mcs/class/System.Data/System.Data.SqlClient/SqlDataReader.cs

   1 //
   2 // System.Data.SqlClient.SqlDataReader.cs
   3 //
   4 // Author:
   5 //   Rodrigo Moya (rodrigo@ximian.com)
   6 //   Daniel Morgan (danmorg@sc.rr.com)
   7 //   Tim Coleman (tim@timcoleman.com)
   8 //
   9 // (C) Ximian, Inc 2002
  10 // (C) Daniel Morgan 2002
  11 // Copyright (C) Tim Coleman, 2002
  12 //
  13
  14 //
  15 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  16 //
  17 // Permission is hereby granted, free of charge, to any person obtaining
  18 // a copy of this software and associated documentation files (the
  19 // "Software"), to deal in the Software without restriction, including
  20 // without limitation the rights to use, copy, modify, merge, publish,
  21 // distribute, sublicense, and/or sell copies of the Software, and to
  22 // permit persons to whom the Software is furnished to do so, subject to
  23 // the following conditions:
  24 //
  25 // The above copyright notice and this permission notice shall be
  26 // included in all copies or substantial portions of the Software.
  27 //
  28 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  29 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  30 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  31 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  32 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  33 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  34 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  35 //
  36
  37 using Mono.Data.Tds.Protocol;
  38 using System;
  39 using System.IO;
  40 using System.Text;
  41 using System.Collections;
  42 using System.ComponentModel;
  43 using System.Data;
  44 using System.Data.Common;
  45 using System.Data.SqlTypes;
  46 using System.Globalization;
  47 using System.Xml;
  48
  49 namespace System.Data.SqlClient
  50 {
  51 #if NET_2_0
  52         public class SqlDataReader : DbDataReader, IDataReader, IDisposable, IDataRecord
  53 #else
  54         public sealed class SqlDataReader : MarshalByRefObject, IEnumerable, IDataReader, IDisposable, IDataRecord
  55 #endif // NET_2_0
  56         {
  57                 #region Fields
  58
  59                 SqlCommand command;
  60                 bool disposed;
  61                 bool isClosed;
  62                 bool moreResults;
  63                 int resultsRead;
  64                 int rowsRead;
  65                 DataTable schemaTable;
  66                 bool haveRead;
  67                 bool readResult;
  68                 bool readResultUsed;
  69 #if NET_2_0
  70                 int visibleFieldCount;
  71 #endif
  72
  73                 #endregion // Fields
  74
  75                 const int COLUMN_NAME_IDX = 0;
  76                 const int COLUMN_ORDINAL_IDX = 1;
  77                 const int COLUMN_SIZE_IDX = 2;
  78                 const int NUMERIC_PRECISION_IDX = 3;
  79                 const int NUMERIC_SCALE_IDX = 4;
  80                 const int IS_UNIQUE_IDX = 5;
  81                 const int IS_KEY_IDX = 6;
  82                 const int BASE_SERVER_NAME_IDX = 7;
  83                 const int BASE_CATALOG_NAME_IDX = 8;
  84                 const int BASE_COLUMN_NAME_IDX = 9;
  85                 const int BASE_SCHEMA_NAME_IDX = 10;
  86                 const int BASE_TABLE_NAME_IDX = 11;
  87                 const int DATA_TYPE_IDX = 12;
  88                 const int ALLOW_DBNULL_IDX = 13;
  89                 const int PROVIDER_TYPE_IDX = 14;
  90                 const int IS_ALIASED_IDX = 15;
  91                 const int IS_EXPRESSION_IDX = 16;
  92                 const int IS_IDENTITY_IDX = 17;
  93                 const int IS_AUTO_INCREMENT_IDX = 18;
  94                 const int IS_ROW_VERSION_IDX = 19;
  95                 const int IS_HIDDEN_IDX = 20;
  96                 const int IS_LONG_IDX = 21;
  97                 const int IS_READ_ONLY_IDX = 22;
  98                 const int PROVIDER_SPECIFIC_TYPE_IDX = 23;
  99                 const int DATA_TYPE_NAME_IDX = 24;
 100                 const int XML_SCHEMA_COLLCTN_DB_IDX = 25;
 101                 const int XML_SCHEMA_COLLCTN_OWN_SCHEMA_IDX = 26;
 102                 const int XML_SCHEMA_COLLCTN_NAME_IDX = 27;
 103                 const int UDT_ASMBLY_QUALIFIED_NAME_IDX = 28;
 104                 const int NON_VER_PROVIDER_TYPE_IDX = 29;
 105                 const int IS_COLUMN_SET = 30;
 106
 107                 #region Constructors
 108
 109                 internal SqlDataReader (SqlCommand command)
 110                 {
 111                         this.command = command;
 112                         command.Tds.RecordsAffected = -1;
 113                         NextResult ();
 114                 }
 115
 116                 #endregion // Constructors
 117
 118                 #region Properties
 119
 120                 public
 121 #if NET_2_0
 122                 override
 123 #endif // NET_2_0
 124                 int Depth {
 125                         get { return 0; }
 126                 }
 127
 128                 public
 129 #if NET_2_0
 130                 override
 131 #endif // NET_2_0
 132                 int FieldCount {
 133                         get {
 134                                 ValidateState ();
 135                                 return command.Tds.Columns.Count;
 136                         }
 137                 }
 138
 139                 public
 140 #if NET_2_0
 141                 override
 142 #endif // NET_2_0
 143                 bool IsClosed {
 144                         get { return isClosed; }
 145                 }
 146
 147                 public
 148 #if NET_2_0
 149                 override
 150 #endif // NET_2_0
 151                 object this [int i] {
 152                         get { return GetValue (i); }
 153                 }
 154
 155                 public
 156 #if NET_2_0
 157                 override
 158 #endif // NET_2_0
 159                 object this [string name] {
 160                         get { return GetValue (GetOrdinal (name)); }
 161                 }
 162
 163                 public
 164 #if NET_2_0
 165                 override
 166 #endif // NET_2_0
 167                 int RecordsAffected {
 168                         get {
 169                                 return command.Tds.RecordsAffected;
 170                         }
 171                 }
 172
 173                 public
 174 #if NET_2_0
 175                 override
 176 #endif // NET_2_0
 177                 bool HasRows {
 178                         get {
 179                                 ValidateState ();
 180
 181                                 if (rowsRead > 0)
 182                                         return true;
 183                                 if (!haveRead)
 184                                         readResult = ReadRecord ();
 185                                 return readResult;
 186                         }
 187                 }
 188 #if NET_2_0
 189                 public override int VisibleFieldCount {
 190                         get { return visibleFieldCount; }
 191                 }
 192
 193                 protected SqlConnection Connection {
 194                         get { return command.Connection; }
 195                 }
 196
 197                 protected bool IsCommandBehavior (CommandBehavior condition) {
 198                         return condition == command.CommandBehavior;
 199                 }
 200 #endif
 201
 202                 #endregion // Properties
 203
 204                 #region Methods
 205
 206                 public
 207 #if NET_2_0
 208                 override
 209 #endif // NET_2_0
 210                 void Close ()
 211                 {
 212                         if (IsClosed)
 213                                 return;
 214                         // skip to end & read output parameters.
 215                         while (NextResult ())
 216                                 ;
 217                         isClosed = true;
 218                         command.CloseDataReader ();
 219                 }
 220
 221                 private static DataTable ConstructSchemaTable ()
 222                 {
 223                         Type booleanType = typeof (bool);
 224                         Type stringType = typeof (string);
 225                         Type intType = typeof (int);
 226 #if NET_2_0
 227                         Type typeType = typeof (Type);
 228 #endif
 229                         Type shortType = typeof (short);
 230
 231                         DataTable schemaTable = new DataTable ("SchemaTable");
 232                         schemaTable.Columns.Add ("ColumnName", stringType);
 233                         schemaTable.Columns.Add ("ColumnOrdinal", intType);
 234                         schemaTable.Columns.Add ("ColumnSize", intType);
 235                         schemaTable.Columns.Add ("NumericPrecision", shortType);
 236                         schemaTable.Columns.Add ("NumericScale", shortType);
 237                         schemaTable.Columns.Add ("IsUnique", booleanType);
 238                         schemaTable.Columns.Add ("IsKey", booleanType);
 239                         schemaTable.Columns.Add ("BaseServerName", stringType);
 240                         schemaTable.Columns.Add ("BaseCatalogName", stringType);
 241                         schemaTable.Columns.Add ("BaseColumnName", stringType);
 242                         schemaTable.Columns.Add ("BaseSchemaName", stringType);
 243                         schemaTable.Columns.Add ("BaseTableName", stringType);
 244 #if NET_2_0
 245                         schemaTable.Columns.Add ("DataType", typeType);
 246 #else
 247                         schemaTable.Columns.Add ("DataType", typeof (object));
 248 #endif
 249                         schemaTable.Columns.Add ("AllowDBNull", booleanType);
 250                         schemaTable.Columns.Add ("ProviderType", intType);
 251                         schemaTable.Columns.Add ("IsAliased", booleanType);
 252                         schemaTable.Columns.Add ("IsExpression", booleanType);
 253                         schemaTable.Columns.Add ("IsIdentity", booleanType);
 254                         schemaTable.Columns.Add ("IsAutoIncrement", booleanType);
 255                         schemaTable.Columns.Add ("IsRowVersion", booleanType);
 256                         schemaTable.Columns.Add ("IsHidden", booleanType);
 257                         schemaTable.Columns.Add ("IsLong", booleanType);
 258                         schemaTable.Columns.Add ("IsReadOnly", booleanType);
 259 #if NET_2_0
 260                         schemaTable.Columns.Add ("ProviderSpecificDataType", typeType);
 261                         schemaTable.Columns.Add ("DataTypeName", stringType);
 262                         schemaTable.Columns.Add ("XmlSchemaCollectionDatabase", stringType);
 263                         schemaTable.Columns.Add ("XmlSchemaCollectionOwningSchema", stringType);
 264                         schemaTable.Columns.Add ("XmlSchemaCollectionName", stringType);
 265                         schemaTable.Columns.Add ("UdtAssemblyQualifiedName", stringType);
 266                         schemaTable.Columns.Add ("NonVersionedProviderType", intType);
 267                         schemaTable.Columns.Add ("IsColumnSet", booleanType);
 268 #endif
 269
 270                         return schemaTable;
 271                 }
 272
 273                 private string GetSchemaRowTypeName (TdsColumnType ctype, int csize, short precision, short scale)
 274                 {
 275                         int dbType;
 276                         bool isLong;
 277                         Type fieldType;
 278
 279                         string typeName;
 280                         GetSchemaRowType (ctype, csize, precision, scale,
 281                                 out dbType, out fieldType, out isLong,
 282                                 out typeName);
 283                         return typeName;
 284                 }
 285
 286                 private Type GetSchemaRowFieldType (TdsColumnType ctype, int csize, short precision, short scale)
 287                 {
 288                         int dbType;
 289                         bool isLong;
 290                         Type fieldType;
 291                         string typeName;
 292
 293                         GetSchemaRowType (ctype, csize, precision, scale,
 294                                 out dbType, out fieldType, out isLong,
 295                                 out typeName);
 296                         return fieldType;
 297                 }
 298
 299                 SqlDbType GetSchemaRowDbType (int ordinal)
 300                 {
 301                         int csize;
 302                         short precision, scale;
 303                         TdsColumnType ctype;
 304                         TdsDataColumn column;
 305
 306                         if (ordinal < 0 || ordinal >= command.Tds.Columns.Count)
 307                                 throw new IndexOutOfRangeException ();
 308
 309                         column = command.Tds.Columns [ordinal];
 310 #if NET_2_0
 311                         ctype = (TdsColumnType) column.ColumnType;
 312                         csize = (int) column.ColumnSize;
 313                         precision = (short) (column.NumericPrecision ?? 0);
 314                         scale = (short) (column.NumericScale ?? 0);
 315 #else
 316                         ctype = (TdsColumnType) column ["ColumnType"];
 317                         csize = (int) column ["ColumnSize"];
 318                         precision = (short) ((byte) column ["NumericPrecision"]);
 319                         scale = (short) ((byte) column ["NumericScale"]);
 320 #endif
 321                         return GetSchemaRowDbType (ctype, csize, precision, scale);
 322                 }
 323
 324                 private SqlDbType GetSchemaRowDbType (TdsColumnType ctype, int csize, short precision, short scale)
 325                 {
 326                         Type fieldType;
 327                         bool isLong;
 328                         string typeName;
 329                         int dbType;
 330
 331                         GetSchemaRowType (ctype, csize, precision, scale,
 332                                 out dbType, out fieldType, out isLong,
 333                                 out typeName);
 334                         return (SqlDbType) dbType;
 335                 }
 336
 337                 private void GetSchemaRowType (TdsColumnType ctype, int csize,
 338                                                short precision, short scale,
 339                                                out int dbType, out Type fieldType,
 340                                                out bool isLong, out string typeName)
 341                 {
 342                         dbType = -1;
 343                         typeName = string.Empty;
 344                         isLong = false;
 345                         fieldType = typeof (Type);
 346
 347                         switch (ctype) {
 348                                 case TdsColumnType.Int1:
 349                                 case TdsColumnType.Int2:
 350                                 case TdsColumnType.Int4:
 351                                 case TdsColumnType.IntN:
 352                                 case TdsColumnType.BigInt:
 353                                         switch (csize) {
 354                                         case 1:
 355                                                 typeName = "tinyint";
 356                                                 dbType = (int) SqlDbType.TinyInt;
 357                                                 fieldType = typeof (byte);
 358                                                 isLong = false;
 359                                                 break;
 360                                         case 2:
 361                                                 typeName = "smallint";
 362                                                 dbType = (int) SqlDbType.SmallInt;
 363                                                 fieldType = typeof (short);
 364                                                 isLong = false;
 365                                                 break;
 366                                         case 4:
 367                                                 typeName = "int";
 368                                                 dbType = (int) SqlDbType.Int;
 369                                                 fieldType = typeof (int);
 370                                                 isLong = false;
 371                                                 break;
 372                                         case 8:
 373                                                 typeName = "bigint";
 374                                                 dbType = (int) SqlDbType.BigInt;
 375                                                 fieldType = typeof (long);
 376                                                 isLong = false;
 377                                                 break;
 378                                         }
 379                                         break;
 380                                 case TdsColumnType.Real:
 381                                 case TdsColumnType.Float8:
 382                                 case TdsColumnType.FloatN:
 383                                         switch (csize) {
 384                                         case 4:
 385                                                 typeName = "real";
 386                                                 dbType = (int) SqlDbType.Real;
 387                                                 fieldType = typeof (float);
 388                                                 isLong = false;
 389                                                 break;
 390                                         case 8:
 391                                                 typeName = "float";
 392                                                 dbType = (int) SqlDbType.Float;
 393                                                 fieldType = typeof (double);
 394                                                 isLong = false;
 395                                                 break;
 396                                         }
 397                                         break;
 398                                 case TdsColumnType.Image :
 399                                         typeName = "image";
 400                                         dbType = (int) SqlDbType.Image;
 401                                         fieldType = typeof (byte[]);
 402                                         isLong = true;
 403                                         break;
 404                                 case TdsColumnType.Text :
 405                                         typeName = "text";
 406                                         dbType = (int) SqlDbType.Text;
 407                                         fieldType = typeof (string);
 408                                         isLong = true;
 409                                         break;
 410                                 case TdsColumnType.UniqueIdentifier :
 411                                         typeName = "uniqueidentifier";
 412                                         dbType = (int) SqlDbType.UniqueIdentifier;
 413                                         fieldType = typeof (Guid);
 414                                         isLong = false;
 415                                         break;
 416                                 case TdsColumnType.VarBinary :
 417                                 case TdsColumnType.BigVarBinary :
 418                                         typeName = "varbinary";
 419                                         dbType = (int) SqlDbType.VarBinary;
 420                                         fieldType = typeof (byte[]);
 421                                         isLong = false;
 422                                         break;
 423                                 case TdsColumnType.VarChar :
 424                                 case TdsColumnType.BigVarChar :
 425                                         typeName = "varchar";
 426                                         dbType = (int) SqlDbType.VarChar;
 427                                         fieldType = typeof (string);
 428                                         isLong = false;
 429                                         break;
 430                                 case TdsColumnType.Binary :
 431                                 case TdsColumnType.BigBinary :
 432                                         typeName = "binary";
 433                                         dbType = (int) SqlDbType.Binary;
 434                                         fieldType = typeof (byte[]);
 435                                         isLong = false;
 436                                         break;
 437                                 case TdsColumnType.Char :
 438                                 case TdsColumnType.BigChar :
 439                                         typeName = "char";
 440                                         dbType = (int) SqlDbType.Char;
 441                                         fieldType = typeof (string);
 442                                         isLong = false;
 443                                         break;
 444                                 case TdsColumnType.Bit :
 445                                 case TdsColumnType.BitN :
 446                                         typeName = "bit";
 447                                         dbType = (int) SqlDbType.Bit;
 448                                         fieldType = typeof (bool);
 449                                         isLong = false;
 450                                         break;
 451                                 case TdsColumnType.DateTime4 :
 452                                 case TdsColumnType.DateTime :
 453                                 case TdsColumnType.DateTimeN :
 454                                         switch (csize) {
 455                                         case 4:
 456                                                 typeName = "smalldatetime";
 457                                                 dbType = (int) SqlDbType.SmallDateTime;
 458                                                 fieldType = typeof (DateTime);
 459                                                 isLong = false;
 460                                                 break;
 461                                         case 8:
 462                                                 typeName = "datetime";
 463                                                 dbType = (int) SqlDbType.DateTime;
 464                                                 fieldType = typeof (DateTime);
 465                                                 isLong = false;
 466                                                 break;
 467                                         }
 468                                         break;
 469                                 case TdsColumnType.Money :
 470                                 case TdsColumnType.MoneyN :
 471                                 case TdsColumnType.Money4 :
 472                                         switch (csize) {
 473                                         case 4:
 474                                                 typeName = "smallmoney";
 475                                                 dbType = (int) SqlDbType.SmallMoney;
 476                                                 fieldType = typeof (decimal);
 477                                                 isLong = false;
 478                                                 break;
 479                                         case 8:
 480                                                 typeName = "money";
 481                                                 dbType = (int) SqlDbType.Money;
 482                                                 fieldType = typeof (decimal);
 483                                                 isLong = false;
 484                                                 break;
 485                                         }
 486                                         break;
 487                                 case TdsColumnType.NText :
 488                                         typeName = "ntext";
 489                                         dbType = (int) SqlDbType.NText;
 490                                         fieldType = typeof (string);
 491                                         isLong = true;
 492                                         break;
 493                                 case TdsColumnType.NVarChar :
 494                                         typeName = "nvarchar";
 495                                         dbType = (int) SqlDbType.NVarChar;
 496                                         fieldType = typeof (string);
 497                                         isLong = false;
 498                                         break;
 499                                 case TdsColumnType.Decimal :
 500                                 case TdsColumnType.Numeric :
 501                                         // TDS 7.0 returns bigint as decimal(19,0)
 502                                         if (precision == 19 && scale == 0) {
 503                                                 typeName = "bigint";
 504                                                 dbType = (int) SqlDbType.BigInt;
 505                                                 fieldType = typeof (long);
 506                                         } else {
 507                                                 typeName = "decimal";
 508                                                 dbType = (int) SqlDbType.Decimal;
 509                                                 fieldType = typeof (decimal);
 510                                         }
 511                                         isLong = false;
 512                                         break;
 513                                 case TdsColumnType.NChar :
 514                                         typeName = "nchar";
 515                                         dbType = (int) SqlDbType.NChar;
 516                                         fieldType = typeof (string);
 517                                         isLong = false;
 518                                         break;
 519                                 case TdsColumnType.SmallMoney :
 520                                         typeName = "smallmoney";
 521                                         dbType = (int) SqlDbType.SmallMoney;
 522                                         fieldType = typeof (decimal);
 523                                         isLong = false;
 524                                         break;
 525                                 default :
 526                                         typeName = "variant";
 527                                         dbType = (int) SqlDbType.Variant;
 528                                         fieldType = typeof (object);
 529                                         isLong = false;
 530                                         break;
 531                         }
 532                 }
 533
 534 #if NET_2_0
 535                 new
 536 #endif
 537                 void Dispose (bool disposing)
 538                 {
 539                         if (!disposed) {
 540                                 if (disposing) {
 541                                         if (schemaTable != null)
 542                                                 schemaTable.Dispose ();
 543                                         Close ();
 544                                         command = null;
 545                                 }
 546                                 disposed = true;
 547                         }
 548                 }
 549
 550                 public
 551 #if NET_2_0
 552                 override
 553 #endif // NET_2_0
 554                 bool GetBoolean (int i)
 555                 {
 556                         object value = GetValue (i);
 557                         if (!(value is bool)) {
 558                                 if (value is DBNull) throw new SqlNullValueException ();
 559                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 560                         }
 561                         return (bool) value;
 562                 }
 563
 564                 public
 565 #if NET_2_0
 566                 override
 567 #endif // NET_2_0
 568                 byte GetByte (int i)
 569                 {
 570                         object value = GetValue (i);
 571                         if (!(value is byte)) {
 572                                 if (value is DBNull) throw new SqlNullValueException ();
 573                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 574                         }
 575                         return (byte) value;
 576                 }
 577
 578                 public
 579 #if NET_2_0
 580                 override
 581 #endif // NET_2_0
 582                 long GetBytes (int i, long dataIndex, byte[] buffer, int bufferIndex, int length)
 583                 {
 584                         if ((command.CommandBehavior & CommandBehavior.SequentialAccess) != 0) {
 585                                 ValidateState ();
 586                                 EnsureDataAvailable ();
 587
 588                                 try {
 589                                         long len = ((Tds)command.Tds).GetSequentialColumnValue (i, dataIndex, buffer, bufferIndex, length);
 590                                         if (len == -1)
 591                                                 throw CreateGetBytesOnInvalidColumnTypeException (i);
 592                                         if (len == -2)
 593 #if NET_2_0
 594                                                 throw new SqlNullValueException ();
 595 #else
 596                                                 return 0;
 597 #endif
 598                                         return len;
 599                                 } catch (TdsInternalException ex) {
 600                                         command.Connection.Close ();
 601                                         throw SqlException.FromTdsInternalException ((TdsInternalException) ex);
 602                                 }
 603                         }
 604
 605                         object value = GetValue (i);
 606                         if (!(value is byte [])) {
 607                                 SqlDbType type = GetSchemaRowDbType (i);
 608                                 switch (type) {
 609                                 case SqlDbType.Image:
 610                                         if (value is DBNull)
 611                                                 throw new SqlNullValueException ();
 612                                         break;
 613                                 case SqlDbType.Text:
 614 #if NET_2_0
 615                                         string text = value as string;
 616                                         if (text != null)
 617                                                 value = Encoding.Default.GetBytes (text);
 618                                         else
 619                                                 value = null;
 620                                         break;
 621 #else
 622                                         throw new InvalidCastException ();
 623 #endif
 624                                 case SqlDbType.NText:
 625 #if NET_2_0
 626                                         string ntext = value as string;
 627                                         if (ntext != null)
 628                                                 value = Encoding.Unicode.GetBytes (ntext);
 629                                         else
 630                                                 value = null;
 631                                         break;
 632 #else
 633                                         throw new InvalidCastException ();
 634 #endif
 635                                 default:
 636                                         throw CreateGetBytesOnInvalidColumnTypeException (i);
 637                                 }
 638                         }
 639
 640                         if (buffer == null)
 641                                 return ((byte []) value).Length; // Return length of data
 642
 643                         // Copy data into buffer
 644                         int availLen = (int) ( ( (byte []) value).Length - dataIndex);
 645                         if (availLen < length)
 646                                 length = availLen;
 647                         if (dataIndex < 0)
 648                                 return 0;
 649
 650                         Array.Copy ((byte []) value, (int) dataIndex, buffer, bufferIndex, length);
 651                         return length; // return actual read count
 652                 }
 653
 654                 [EditorBrowsableAttribute (EditorBrowsableState.Never)]
 655                 public
 656 #if NET_2_0
 657                 override
 658 #endif // NET_2_0
 659                 char GetChar (int i)
 660                 {
 661                         throw new NotSupportedException ();
 662                 }
 663
 664                 public
 665 #if NET_2_0
 666                 override
 667 #endif // NET_2_0
 668                 long GetChars (int i, long dataIndex, char[] buffer, int bufferIndex, int length)
 669                 {
 670                         if ((command.CommandBehavior & CommandBehavior.SequentialAccess) != 0) {
 671                                 ValidateState ();
 672                                 EnsureDataAvailable ();
 673
 674                                 if (i < 0 || i >= command.Tds.Columns.Count)
 675                                         throw new IndexOutOfRangeException ();
 676
 677                                 Encoding encoding = null;
 678                                 byte mul = 1;
 679                                 TdsColumnType colType = (TdsColumnType) command.Tds.Columns[i]["ColumnType"];
 680                                 switch (colType) {
 681                                         case TdsColumnType.Text :
 682                                         case TdsColumnType.VarChar:
 683                                         case TdsColumnType.Char:
 684                                         case TdsColumnType.BigVarChar:
 685                                                 encoding = Encoding.ASCII;
 686                                                 break;
 687                                         case TdsColumnType.NText :
 688                                         case TdsColumnType.NVarChar:
 689                                         case TdsColumnType.NChar:
 690                                                 encoding = Encoding.Unicode;
 691                                                 mul = 2;
 692                                                 break;
 693                                         default :
 694                                                 return -1;
 695                                 }
 696
 697                                 long count = 0;
 698                                 if (buffer == null) {
 699                                         count = GetBytes (i,0,(byte[]) null,0,0);
 700                                         return (count/mul);
 701                                 }
 702
 703                                 length *= mul;
 704                                 byte[] arr = new byte [length];
 705                                 count = GetBytes (i, dataIndex, arr, 0, length);
 706                                 if (count == -1)
 707                                         throw new InvalidCastException ("Specified cast is not valid");
 708
 709                                 Char[] val = encoding.GetChars (arr, 0, (int)count);
 710                                 val.CopyTo (buffer, bufferIndex);
 711                                 return val.Length;
 712                         }
 713
 714                         char [] valueBuffer;
 715                         object value = GetValue (i);
 716
 717                         if (value is char[])
 718                                 valueBuffer = (char[])value;
 719                         else if (value is string)
 720                                 valueBuffer = ((string)value).ToCharArray();
 721                         else {
 722                                 if (value is DBNull) throw new SqlNullValueException ();
 723                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 724                         }
 725
 726                         if ( buffer == null ) {
 727                                 // Return length of data
 728                                 return valueBuffer.Length;
 729                         }
 730                         else {
 731                                 // Copy data into buffer
 732                                 Array.Copy (valueBuffer, (int) dataIndex, buffer, bufferIndex, length);
 733                                 return valueBuffer.Length - dataIndex;
 734                         }
 735                 }
 736
 737 #if !NET_2_0
 738                 [EditorBrowsableAttribute (EditorBrowsableState.Never)]
 739                 public new IDataReader GetData (int i)
 740                 {
 741                         return ((IDataReader) this [i]);
 742                 }
 743 #endif
 744
 745                 public
 746 #if NET_2_0
 747                 override
 748 #endif // NET_2_0
 749                 string GetDataTypeName (int i)
 750                 {
 751                         TdsDataColumn column;
 752                         TdsColumnType ctype;
 753                         int csize;
 754                         short precision;
 755                         short scale;
 756
 757                         ValidateState ();
 758
 759                         if (i < 0 || i >= command.Tds.Columns.Count)
 760                                 throw new IndexOutOfRangeException ();
 761
 762                         column = command.Tds.Columns [i];
 763 #if NET_2_0
 764                         ctype = (TdsColumnType) column.ColumnType;
 765                         csize = (int) column.ColumnSize;
 766                         precision = (short) (column.NumericPrecision ?? 0);
 767                         scale = (short) (column.NumericScale ?? 0);
 768 #else
 769                         ctype = (TdsColumnType) column ["ColumnType"];
 770                         csize = (int) column ["ColumnSize"];
 771                         precision = (short) ((byte) column ["NumericPrecision"]);
 772                         scale = (short) ((byte) column ["NumericScale"]);
 773 #endif
 774                         return GetSchemaRowTypeName (ctype, csize, precision, scale);
 775                 }
 776
 777                 public
 778 #if NET_2_0
 779                 override
 780 #endif // NET_2_0
 781                 DateTime GetDateTime (int i)
 782                 {
 783                         object value = GetValue (i);
 784                         if (!(value is DateTime)) {
 785                                 if (value is DBNull) throw new SqlNullValueException ();
 786                                 else throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 787                         }
 788                         return (DateTime) value;
 789                 }
 790
 791                 public
 792 #if NET_2_0
 793                 override
 794 #endif // NET_2_0
 795                 decimal GetDecimal (int i)
 796                 {
 797                         object value = GetValue (i);
 798                         if (!(value is decimal)) {
 799                                 if (value is DBNull) throw new SqlNullValueException ();
 800                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 801                         }
 802                         return (decimal) value;
 803                 }
 804
 805                 public
 806 #if NET_2_0
 807                 override
 808 #endif // NET_2_0
 809                 double GetDouble (int i)
 810                 {
 811                         object value = GetValue (i);
 812                         if (!(value is double)) {
 813                                 if (value is DBNull) throw new SqlNullValueException ();
 814                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 815                         }
 816                         return (double) value;
 817                 }
 818
 819                 public
 820 #if NET_2_0
 821                 override
 822 #endif // NET_2_0
 823                 Type GetFieldType (int i)
 824                 {
 825                         TdsDataColumn column;
 826                         TdsColumnType ctype;
 827                         int csize;
 828                         short precision;
 829                         short scale;
 830
 831                         ValidateState ();
 832
 833                         if (i < 0 || i >= command.Tds.Columns.Count)
 834                                 throw new IndexOutOfRangeException ();
 835
 836                         column = command.Tds.Columns [i];
 837 #if NET_2_0
 838                         ctype = (TdsColumnType) column.ColumnType;
 839                         csize = (int) column.ColumnSize;
 840                         precision = (short) (column.NumericPrecision ?? 0);
 841                         scale = (short) (column.NumericScale ?? 0);
 842 #else
 843                         ctype = (TdsColumnType) column ["ColumnType"];
 844                         csize = (int) column ["ColumnSize"];
 845                         precision = (short) ((byte) column ["NumericPrecision"]);
 846                         scale = (short) ((byte) column ["NumericScale"]);
 847 #endif
 848                         return GetSchemaRowFieldType (ctype, csize, precision,
 849                                 scale);
 850                 }
 851
 852                 public
 853 #if NET_2_0
 854                 override
 855 #endif // NET_2_0
 856                 float GetFloat (int i)
 857                 {
 858                         object value = GetValue (i);
 859                         if (!(value is float)) {
 860                                 if (value is DBNull) throw new SqlNullValueException ();
 861                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 862                         }
 863                         return (float) value;
 864                 }
 865
 866                 public
 867 #if NET_2_0
 868                 override
 869 #endif // NET_2_0
 870                 Guid GetGuid (int i)
 871                 {
 872                         object value = GetValue (i);
 873                         if (!(value is Guid)) {
 874                                 if (value is DBNull) throw new SqlNullValueException ();
 875                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 876                         }
 877                         return (Guid) value;
 878                 }
 879
 880                 public
 881 #if NET_2_0
 882                 override
 883 #endif // NET_2_0
 884                 short GetInt16 (int i)
 885                 {
 886                         object value = GetValue (i);
 887                         if (!(value is short)) {
 888                                 if (value is DBNull) throw new SqlNullValueException ();
 889                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 890                         }
 891                         return (short) value;
 892                 }
 893
 894                 public
 895 #if NET_2_0
 896                 override
 897 #endif // NET_2_0
 898                 int GetInt32 (int i)
 899                 {
 900                         object value = GetValue (i);
 901                         if (!(value is int)) {
 902                                 if (value is DBNull) throw new SqlNullValueException ();
 903                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 904                         }
 905                         return (int) value;
 906                 }
 907
 908                 public
 909 #if NET_2_0
 910                 override
 911 #endif // NET_2_0
 912                 long GetInt64 (int i)
 913                 {
 914                         object value = GetValue (i);
 915                         if (!(value is long)) {
 916                                 if (value is DBNull) throw new SqlNullValueException ();
 917                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 918                         }
 919                         return (long) value;
 920                 }
 921
 922                 public
 923 #if NET_2_0
 924                 override
 925 #endif // NET_2_0
 926                 string GetName (int i)
 927                 {
 928                         ValidateState ();
 929
 930                         if (i < 0 || i >= command.Tds.Columns.Count)
 931                                 throw new IndexOutOfRangeException ();
 932 #if NET_2_0
 933                         return (string) command.Tds.Columns[i].ColumnName;
 934 #else
 935                         return (string) command.Tds.Columns[i]["ColumnName"];
 936 #endif
 937                 }
 938
 939                 public
 940 #if NET_2_0
 941                 override
 942 #endif // NET_2_0
 943                 int GetOrdinal (string name)
 944                 {
 945                         ValidateState ();
 946
 947                         if (name == null)
 948                                 throw new ArgumentNullException ("fieldName");
 949
 950                         string colName;
 951                         foreach (TdsDataColumn schema in command.Tds.Columns) {
 952 #if NET_2_0
 953                                 colName = schema.ColumnName;
 954                                 if (colName.Equals (name) || String.Compare (colName, name, true) == 0)
 955                                         return (int) schema.ColumnOrdinal;
 956 #else
 957                                 colName = (string) schema["ColumnName"];
 958                                 if (colName.Equals (name) || String.Compare (colName, name, true) == 0)
 959                                         return (int) schema["ColumnOrdinal"];
 960 #endif
 961                         }
 962                         throw new IndexOutOfRangeException ();
 963                 }
 964
 965                 public
 966 #if NET_2_0
 967                 override
 968 #endif // NET_2_0
 969                 DataTable GetSchemaTable ()
 970                 {
 971                         ValidateState ();
 972
 973                         if (schemaTable == null)
 974                                 schemaTable = ConstructSchemaTable ();
 975
 976                         if (schemaTable.Rows != null && schemaTable.Rows.Count > 0)
 977                                 return schemaTable;
 978
 979                         if (!moreResults)
 980                                 return null;
 981
 982                         foreach (TdsDataColumn schema in command.Tds.Columns) {
 983                                 DataRow row = schemaTable.NewRow ();
 984
 985 #if NET_2_0
 986                                 row [COLUMN_NAME_IDX]           = GetSchemaValue (schema.ColumnName);
 987                                 row [COLUMN_ORDINAL_IDX]                = GetSchemaValue (schema.ColumnOrdinal);
 988                                 row [IS_UNIQUE_IDX]             = GetSchemaValue (schema.IsUnique);
 989                                 row [IS_AUTO_INCREMENT_IDX]             = GetSchemaValue (schema.IsAutoIncrement);
 990                                 row [IS_ROW_VERSION_IDX]                = GetSchemaValue (schema.IsRowVersion);
 991                                 row [IS_HIDDEN_IDX]             = GetSchemaValue (schema.IsHidden);
 992                                 row [IS_IDENTITY_IDX]           = GetSchemaValue (schema.IsIdentity);
 993                                 row [NUMERIC_PRECISION_IDX]     = GetSchemaValue (schema.NumericPrecision);
 994                                 row [IS_KEY_IDX]                        = GetSchemaValue (schema.IsKey);
 995                                 row [IS_ALIASED_IDX]            = GetSchemaValue (schema.IsAliased);
 996                                 row [IS_EXPRESSION_IDX]         = GetSchemaValue (schema.IsExpression);
 997                                 row [IS_READ_ONLY_IDX]          = GetSchemaValue (schema.IsReadOnly);
 998                                 row [BASE_SERVER_NAME_IDX]              = GetSchemaValue (schema.BaseServerName);
 999                                 row [BASE_CATALOG_NAME_IDX]             = GetSchemaValue (schema.BaseCatalogName);
1000                                 row [BASE_COLUMN_NAME_IDX]              = GetSchemaValue (schema.BaseColumnName);
1001                                 row [BASE_SCHEMA_NAME_IDX]              = GetSchemaValue (schema.BaseSchemaName);
1002                                 row [BASE_TABLE_NAME_IDX]               = GetSchemaValue (schema.BaseTableName);
1003                                 row [ALLOW_DBNULL_IDX]          = GetSchemaValue (schema.AllowDBNull);
1004                                 row [PROVIDER_SPECIFIC_TYPE_IDX] = DBNull.Value;
1005                                 row [DATA_TYPE_NAME_IDX] = GetSchemaValue (schema.DataTypeName);
1006                                 row [XML_SCHEMA_COLLCTN_DB_IDX] = DBNull.Value;
1007                                 row [XML_SCHEMA_COLLCTN_OWN_SCHEMA_IDX] = DBNull.Value;
1008                                 row [XML_SCHEMA_COLLCTN_NAME_IDX] = DBNull.Value;
1009                                 row [UDT_ASMBLY_QUALIFIED_NAME_IDX] = DBNull.Value;
1010                                 row [NON_VER_PROVIDER_TYPE_IDX] = DBNull.Value;
1011                                 row [IS_COLUMN_SET] = DBNull.Value;
1012 #else
1013                                 row [COLUMN_NAME_IDX]           = GetSchemaValue (schema, "ColumnName");
1014                                 row [COLUMN_ORDINAL_IDX]                = GetSchemaValue (schema, "ColumnOrdinal");
1015                                 row [IS_UNIQUE_IDX]             = GetSchemaValue (schema, "IsUnique");
1016                                 row [IS_AUTO_INCREMENT_IDX]             = GetSchemaValue (schema, "IsAutoIncrement");
1017                                 row [IS_ROW_VERSION_IDX]                = GetSchemaValue (schema, "IsRowVersion");
1018                                 row [IS_HIDDEN_IDX]             = GetSchemaValue (schema, "IsHidden");
1019                                 row [IS_IDENTITY_IDX]           = GetSchemaValue (schema, "IsIdentity");
1020                                 row [IS_KEY_IDX]                        = GetSchemaValue (schema, "IsKey");
1021                                 row [IS_ALIASED_IDX]            = GetSchemaValue (schema, "IsAliased");
1022                                 row [IS_EXPRESSION_IDX]         = GetSchemaValue (schema, "IsExpression");
1023                                 row [IS_READ_ONLY_IDX]          = GetSchemaValue (schema, "IsReadOnly");
1024                                 row [BASE_SERVER_NAME_IDX]              = GetSchemaValue (schema, "BaseServerName");
1025                                 row [BASE_CATALOG_NAME_IDX]             = GetSchemaValue (schema, "BaseCatalogName");
1026                                 row [BASE_COLUMN_NAME_IDX]              = GetSchemaValue (schema, "BaseColumnName");
1027                                 row [BASE_SCHEMA_NAME_IDX]              = GetSchemaValue (schema, "BaseSchemaName");
1028                                 row [BASE_TABLE_NAME_IDX]               = GetSchemaValue (schema, "BaseTableName");
1029                                 row [ALLOW_DBNULL_IDX]          = GetSchemaValue (schema, "AllowDBNull");
1030 #endif
1031                                 // We don't always get the base column name.
1032                                 if (row [BASE_COLUMN_NAME_IDX] == DBNull.Value)
1033                                         row [BASE_COLUMN_NAME_IDX] = row [COLUMN_NAME_IDX];
1034
1035                                 TdsColumnType ctype;
1036                                 int csize, dbType;
1037                                 Type fieldType;
1038                                 bool isLong;
1039                                 string typeName;
1040                                 short precision;
1041                                 short scale;
1042 #if NET_2_0
1043                                 ctype = (TdsColumnType) schema.ColumnType;
1044                                 csize = (int) schema.ColumnSize;
1045                                 precision = (short) GetSchemaValue (schema.NumericPrecision);
1046                                 scale = (short) GetSchemaValue (schema.NumericScale);
1047 #else
1048                                 ctype = (TdsColumnType) schema ["ColumnType"];
1049                                 csize = (int) schema ["ColumnSize"];
1050                                 precision = (short) ((byte) GetSchemaValue (schema, "NumericPrecision"));
1051                                 scale = (short) ((byte) GetSchemaValue (schema, "NumericScale"));
1052 #endif
1053
1054                                 GetSchemaRowType (ctype, csize, precision, scale,
1055                                         out dbType, out fieldType, out isLong,
1056                                         out typeName);
1057
1058                                 row [COLUMN_SIZE_IDX] = csize;
1059                                 row [NUMERIC_PRECISION_IDX] = precision;
1060                                 row [NUMERIC_SCALE_IDX] = scale;
1061                                 row [PROVIDER_TYPE_IDX] = dbType;
1062                                 row [DATA_TYPE_IDX] = fieldType;
1063                                 row [IS_LONG_IDX] = isLong;
1064 #if NET_2_0
1065                                 if ((bool)row [IS_HIDDEN_IDX] == false)
1066                                         visibleFieldCount += 1;
1067 #endif
1068
1069                                 schemaTable.Rows.Add (row);
1070                         }
1071                         return schemaTable;
1072                 }
1073
1074                 private static object GetSchemaValue (TdsDataColumn schema, string key)
1075                 {
1076                         object val = schema [key];
1077                         if (val != null)
1078                                 return val;
1079                         else
1080                                 return DBNull.Value;
1081                 }
1082
1083 #if NET_2_0
1084                 static object GetSchemaValue (object value)
1085                 {
1086                         if (value == null)
1087                                 return DBNull.Value;
1088
1089                         return value;
1090                 }
1091 #endif
1092
1093                 public
1094 #if NET_2_0
1095                 virtual
1096 #endif
1097                 SqlBinary GetSqlBinary (int i)
1098                 {
1099                         object value = GetSqlValue (i);
1100                         if (!(value is SqlBinary))
1101                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1102                         return (SqlBinary) value;
1103                 }
1104
1105                 public
1106 #if NET_2_0
1107                 virtual
1108 #endif
1109                 SqlBoolean GetSqlBoolean (int i)
1110                 {
1111                         object value = GetSqlValue (i);
1112                         if (!(value is SqlBoolean))
1113                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1114                         return (SqlBoolean) value;
1115                 }
1116
1117                 public
1118 #if NET_2_0
1119                 virtual
1120 #endif
1121                 SqlByte GetSqlByte (int i)
1122                 {
1123                         object value = GetSqlValue (i);
1124                         if (!(value is SqlByte))
1125                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1126                         return (SqlByte) value;
1127                 }
1128
1129                 public
1130 #if NET_2_0
1131                 virtual
1132 #endif
1133                 SqlDateTime GetSqlDateTime (int i)
1134                 {
1135                         object value = GetSqlValue (i);
1136                         if (!(value is SqlDateTime))
1137                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1138                         return (SqlDateTime) value;
1139                 }
1140
1141                 public
1142 #if NET_2_0
1143                 virtual
1144 #endif
1145                 SqlDecimal GetSqlDecimal (int i)
1146                 {
1147                         object value = GetSqlValue (i);
1148                         if (!(value is SqlDecimal))
1149                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1150                         return (SqlDecimal) value;
1151                 }
1152
1153                 public
1154 #if NET_2_0
1155                 virtual
1156 #endif
1157                 SqlDouble GetSqlDouble (int i)
1158                 {
1159                         object value = GetSqlValue (i);
1160                         if (!(value is SqlDouble))
1161                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1162                         return (SqlDouble) value;
1163                 }
1164
1165                 public
1166 #if NET_2_0
1167                 virtual
1168 #endif
1169                 SqlGuid GetSqlGuid (int i)
1170                 {
1171                         object value = GetSqlValue (i);
1172                         if (!(value is SqlGuid))
1173                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1174                         return (SqlGuid) value;
1175                 }
1176
1177                 public
1178 #if NET_2_0
1179                 virtual
1180 #endif
1181                 SqlInt16 GetSqlInt16 (int i)
1182                 {
1183                         object value = GetSqlValue (i);
1184                         if (!(value is SqlInt16))
1185                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1186                         return (SqlInt16) value;
1187                 }
1188
1189                 public
1190 #if NET_2_0
1191                 virtual
1192 #endif
1193                 SqlInt32 GetSqlInt32 (int i)
1194                 {
1195                         object value = GetSqlValue (i);
1196                         if (!(value is SqlInt32))
1197                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1198                         return (SqlInt32) value;
1199                 }
1200
1201                 public
1202 #if NET_2_0
1203                 virtual
1204 #endif
1205                 SqlInt64 GetSqlInt64 (int i)
1206                 {
1207                         object value = GetSqlValue (i);
1208                         if (!(value is SqlInt64))
1209                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1210                         return (SqlInt64) value;
1211                 }
1212
1213                 public
1214 #if NET_2_0
1215                 virtual
1216 #endif
1217                 SqlMoney GetSqlMoney (int i)
1218                 {
1219                         object value = GetSqlValue (i);
1220                         if (!(value is SqlMoney))
1221                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1222                         return (SqlMoney) value;
1223                 }
1224
1225                 public
1226 #if NET_2_0
1227                 virtual
1228 #endif
1229                 SqlSingle GetSqlSingle (int i)
1230                 {
1231                         object value = GetSqlValue (i);
1232                         if (!(value is SqlSingle))
1233                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1234                         return (SqlSingle) value;
1235                 }
1236
1237                 public
1238 #if NET_2_0
1239                 virtual
1240 #endif
1241                 SqlString GetSqlString (int i)
1242                 {
1243                         object value = GetSqlValue (i);
1244                         if (!(value is SqlString))
1245                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1246                         return (SqlString) value;
1247                 }
1248
1249 #if NET_2_0
1250                 public virtual SqlXml GetSqlXml (int i)
1251                 {
1252                         object value = GetSqlValue (i);
1253                         if (!(value is SqlXml)) {
1254                                 if (value is DBNull) {
1255                                         throw new SqlNullValueException ();
1256                                 } else if (command.Tds.TdsVersion <= TdsVersion.tds80 && value is SqlString) {
1257                                         // Workaround for TDS 7/8/8.1 clients
1258                                         // Xml column types are supported only from Sql Server 2005 / TDS 9, however
1259                                         // when a TDS 7/8/8.1 client requests for Xml column data, Sql Server 2005 returns
1260                                         // it as NTEXT
1261                                         MemoryStream stream = null;
1262                                         if (!((SqlString) value).IsNull)
1263                                                 stream = new MemoryStream (Encoding.Unicode.GetBytes (value.ToString()));
1264                                         value = new SqlXml (stream);
1265                                 } else {
1266                                         throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1267                                 }
1268                         }
1269                         return (SqlXml) value;
1270                 }
1271 #endif // NET_2_0
1272
1273                 public
1274 #if NET_2_0
1275                 virtual
1276 #endif
1277                 object GetSqlValue (int i)
1278                 {
1279                         object value = GetValue (i);
1280                         //Console.WriteLine ("Type of value: {0}", value.GetType ());
1281
1282                         SqlDbType type = GetSchemaRowDbType (i);
1283                         switch (type) {
1284                         case SqlDbType.BigInt:
1285                                 if (value == DBNull.Value)
1286                                         return SqlInt64.Null;
1287                                 return (SqlInt64) ((long) value);
1288                         case SqlDbType.Binary:
1289                         case SqlDbType.Image:
1290                         case SqlDbType.VarBinary:
1291                         case SqlDbType.Timestamp:
1292                                 if (value == DBNull.Value)
1293                                         return SqlBinary.Null;
1294                                 return (SqlBinary) ((byte[]) value);
1295                         case SqlDbType.Bit:
1296                                 if (value == DBNull.Value)
1297                                         return SqlBoolean.Null;
1298                                 return (SqlBoolean) ((bool) value);
1299                         case SqlDbType.Char:
1300                         case SqlDbType.NChar:
1301                         case SqlDbType.NText:
1302                         case SqlDbType.NVarChar:
1303                         case SqlDbType.Text:
1304                         case SqlDbType.VarChar:
1305                                 if (value == DBNull.Value)
1306                                         return SqlString.Null;
1307                                 return (SqlString) ((string) value);
1308                         case SqlDbType.DateTime:
1309                         case SqlDbType.SmallDateTime:
1310                                 if (value == DBNull.Value)
1311                                         return SqlDateTime.Null;
1312                                 return (SqlDateTime) ((DateTime) value);
1313                         case SqlDbType.Decimal:
1314                                 if (value == DBNull.Value)
1315                                         return SqlDecimal.Null;
1316                                 if (value is TdsBigDecimal)
1317                                         return SqlDecimal.FromTdsBigDecimal ((TdsBigDecimal) value);
1318                                 if (value is Int64)
1319                                         return (SqlDecimal)((long) value);
1320                                 return (SqlDecimal) ((decimal) value);
1321                         case SqlDbType.Float:
1322                                 if (value == DBNull.Value)
1323                                         return SqlDouble.Null;
1324                                 return (SqlDouble) ((double) value);
1325                         case SqlDbType.Int:
1326                                 if (value == DBNull.Value)
1327                                         return SqlInt32.Null;
1328                                 return (SqlInt32) ((int) value);
1329                         case SqlDbType.Money:
1330                         case SqlDbType.SmallMoney:
1331                                 if (value == DBNull.Value)
1332                                         return SqlMoney.Null;
1333                                 return (SqlMoney) ((decimal) value);
1334                         case SqlDbType.Real:
1335                                 if (value == DBNull.Value)
1336                                         return SqlSingle.Null;
1337                                 return (SqlSingle) ((float) value);
1338                         case SqlDbType.UniqueIdentifier:
1339                                 if (value == DBNull.Value)
1340                                         return SqlGuid.Null;
1341                                 return (SqlGuid) ((Guid) value);
1342                         case SqlDbType.SmallInt:
1343                                 if (value == DBNull.Value)
1344                                         return SqlInt16.Null;
1345                                 return (SqlInt16) ((short) value);
1346                         case SqlDbType.TinyInt:
1347                                 if (value == DBNull.Value)
1348                                         return SqlByte.Null;
1349                                 return (SqlByte) ((byte) value);
1350 #if NET_2_0
1351                         case SqlDbType.Xml:
1352                                 if (value == DBNull.Value)
1353                                         return SqlByte.Null;
1354                                 return (SqlXml) value;
1355 #endif
1356                         }
1357
1358                         throw new InvalidOperationException ("The type of this column is unknown.");
1359                 }
1360
1361                 public
1362 #if NET_2_0
1363                 virtual
1364 #endif
1365                 int GetSqlValues (object[] values)
1366                 {
1367                         ValidateState ();
1368                         EnsureDataAvailable ();
1369
1370                         if (values == null)
1371                                 throw new ArgumentNullException ("values");
1372
1373                         int count = 0;
1374                         int columnCount = command.Tds.Columns.Count;
1375                         int arrayCount = values.Length;
1376
1377                         if (arrayCount > columnCount)
1378                                 count = columnCount;
1379                         else
1380                                 count = arrayCount;
1381
1382                         for (int i = 0; i < count; i += 1)
1383                                 values [i] = GetSqlValue (i);
1384
1385                         return count;
1386                 }
1387
1388                 public
1389 #if NET_2_0
1390                 override
1391 #endif // NET_2_0
1392                 string GetString (int i)
1393                 {
1394                         object value = GetValue (i);
1395                         if (!(value is string)) {
1396                                 if (value is DBNull) throw new SqlNullValueException ();
1397                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1398                         }
1399                         return (string) value;
1400                 }
1401
1402                 public
1403 #if NET_2_0
1404                 override
1405 #endif // NET_2_0
1406                 object GetValue (int i)
1407                 {
1408                         ValidateState ();
1409                         EnsureDataAvailable ();
1410
1411                         if (i < 0 || i >= command.Tds.Columns.Count)
1412                                 throw new IndexOutOfRangeException ();
1413
1414                         try {
1415                                 if ((command.CommandBehavior & CommandBehavior.SequentialAccess) != 0) {
1416                                         return ((Tds)command.Tds).GetSequentialColumnValue (i);
1417                                 }
1418                         } catch (TdsInternalException ex) {
1419                                 command.Connection.Close ();
1420                                 throw SqlException.FromTdsInternalException ((TdsInternalException) ex);
1421                         }
1422
1423                         return command.Tds.ColumnValues [i];
1424                 }
1425
1426                 public
1427 #if NET_2_0
1428                 override
1429 #endif // NET_2_0
1430                 int GetValues (object[] values)
1431                 {
1432                         ValidateState ();
1433                         EnsureDataAvailable ();
1434
1435                         if (values == null)
1436                                 throw new ArgumentNullException ("values");
1437
1438                         int len = values.Length;
1439                         int bigDecimalIndex = command.Tds.ColumnValues.BigDecimalIndex;
1440
1441                         // If a four-byte decimal is stored, then we can't convert to
1442                         // a native type.  Throw an OverflowException.
1443                         if (bigDecimalIndex >= 0 && bigDecimalIndex < len)
1444                                 throw new OverflowException ();
1445                         try {
1446                                 command.Tds.ColumnValues.CopyTo (0, values, 0,
1447                                                                  len > command.Tds.ColumnValues.Count ? command.Tds.ColumnValues.Count : len);
1448                         } catch (TdsInternalException ex) {
1449                                 command.Connection.Close ();
1450                                 throw SqlException.FromTdsInternalException ((TdsInternalException) ex);
1451                         }
1452                         return (len < FieldCount ? len : FieldCount);
1453                 }
1454
1455 #if !NET_2_0
1456                 void IDisposable.Dispose ()
1457                 {
1458                         Dispose (true);
1459                         GC.SuppressFinalize (this);
1460                 }
1461 #endif
1462
1463 #if NET_2_0
1464                 public override IEnumerator GetEnumerator ()
1465 #else
1466                 IEnumerator IEnumerable.GetEnumerator ()
1467 #endif
1468                 {
1469                         return new DbEnumerator (this);
1470                 }
1471
1472                 public
1473 #if NET_2_0
1474                 override
1475 #endif // NET_2_0
1476                 bool IsDBNull (int i)
1477                 {
1478                         return GetValue (i) == DBNull.Value;
1479                 }
1480
1481                 public
1482 #if NET_2_0
1483                 override
1484 #endif // NET_2_0
1485                 bool NextResult ()
1486                 {
1487                         ValidateState ();
1488
1489                         if ((command.CommandBehavior & CommandBehavior.SingleResult) != 0 && resultsRead > 0) {
1490                                 moreResults = false;
1491                                 rowsRead = 0;
1492                                 haveRead = false;
1493                                 return false;
1494                         }
1495
1496                         try {
1497                                 moreResults = command.Tds.NextResult ();
1498                         } catch (TdsInternalException ex) {
1499                                 command.Connection.Close ();
1500                                 throw SqlException.FromTdsInternalException ((TdsInternalException) ex);
1501                         }
1502                         if (!moreResults)
1503                                 command.GetOutputParameters ();
1504                         else {
1505                                 // new schema - don't do anything except reset schemaTable as command.Tds.Columns is already updated
1506                                 schemaTable = null;
1507                         }
1508
1509                         rowsRead = 0;
1510                         haveRead = false;
1511                         resultsRead += 1;
1512                         return moreResults;
1513                 }
1514
1515                 public
1516 #if NET_2_0
1517                 override
1518 #endif // NET_2_0
1519                 bool Read ()
1520                 {
1521                         ValidateState ();
1522
1523                         if (!haveRead || readResultUsed)
1524                                 readResult = ReadRecord ();
1525                         readResultUsed = true;
1526                         return readResult;
1527                 }
1528
1529                 internal bool ReadRecord ()
1530                 {
1531                         readResultUsed = false;
1532
1533                         if ((command.CommandBehavior & CommandBehavior.SingleRow) != 0 && haveRead)
1534                                 return false;
1535                         if ((command.CommandBehavior & CommandBehavior.SchemaOnly) != 0)
1536                                 return false;
1537                         if (!moreResults)
1538                                 return false;
1539
1540                         try {
1541                                 bool result = command.Tds.NextRow ();
1542                                 if (result)
1543                                         rowsRead++;
1544                                 haveRead = true;
1545                                 return result;
1546                         } catch (TdsInternalException ex) {
1547                                 command.Connection.Close ();
1548                                 throw SqlException.FromTdsInternalException ((TdsInternalException) ex);
1549                         }
1550                 }
1551
1552                 void ValidateState ()
1553                 {
1554                         if (IsClosed)
1555                                 throw new InvalidOperationException ("Invalid attempt to read data when reader is closed");
1556                 }
1557
1558                 void EnsureDataAvailable ()
1559                 {
1560                         if (!readResult || !haveRead || !readResultUsed)
1561                                 throw new InvalidOperationException ("No data available.");
1562                 }
1563
1564                 InvalidCastException CreateGetBytesOnInvalidColumnTypeException (int ordinal)
1565                 {
1566                         string message = string.Format (CultureInfo.InvariantCulture,
1567                                 "Invalid attempt to GetBytes on column '{0}'." +
1568                                 "The GetBytes function can only be used on " +
1569                                 "columns of type Text, NText, or Image.",
1570                                 GetName (ordinal));
1571                         return new InvalidCastException (message);
1572                 }
1573
1574 #if NET_2_0
1575                 public override Type GetProviderSpecificFieldType (int i)
1576                 {
1577                         return (GetSqlValue (i).GetType());
1578                 }
1579
1580                 public override object GetProviderSpecificValue (int i)
1581                 {
1582                         return (GetSqlValue (i));
1583                 }
1584
1585                 public override int GetProviderSpecificValues (object [] values)
1586                 {
1587                         return (GetSqlValues (values));
1588                 }
1589
1590                 public virtual SqlBytes GetSqlBytes (int i)
1591                 {
1592                         //object value = GetSqlValue (i);
1593                         //if (!(value is SqlBinary))
1594                         //      throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1595                         Byte[] val = (byte[])GetValue(i);
1596                         SqlBytes sb = new SqlBytes (val);
1597                         return (sb);
1598                 }
1599 #endif // NET_2_0
1600
1601                 #endregion // Methods
1602         }
1603 }