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
  47 namespace System.Data.SqlClient
  48 {
  49 #if NET_2_0
  50         public class SqlDataReader : DbDataReader, IDataReader, IDisposable, IDataRecord
  51 #else
  52         public sealed class SqlDataReader : MarshalByRefObject, IEnumerable, IDataReader, IDisposable, IDataRecord
  53 #endif // NET_2_0
  54         {
  55                 #region Fields
  56
  57                 SqlCommand command;
  58                 ArrayList dataTypeNames;
  59                 bool disposed;
  60                 bool isClosed;
  61                 bool moreResults;
  62                 int resultsRead;
  63                 int rowsRead;
  64                 DataTable schemaTable;
  65                 bool hasRows;
  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
  99                 #region Constructors
 100
 101                 internal SqlDataReader (SqlCommand command)
 102                 {
 103                         readResult = false;
 104                         haveRead = false;
 105                         readResultUsed = false;
 106                         this.command = command;
 107                         resultsRead = 0;
 108                         isClosed = false;
 109                         command.Tds.RecordsAffected = -1;
 110 #if NET_2_0
 111                         visibleFieldCount = 0;
 112 #endif
 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 { return command.Tds.Columns.Count; }
 134                 }
 135
 136                 public
 137 #if NET_2_0
 138                 override
 139 #endif // NET_2_0
 140                 bool IsClosed {
 141                         get { return isClosed; }
 142                 }
 143
 144                 public
 145 #if NET_2_0
 146                 override
 147 #endif // NET_2_0
 148                 object this [int i] {
 149                         get { return GetValue (i); }
 150                 }
 151
 152                 public
 153 #if NET_2_0
 154                 override
 155 #endif // NET_2_0
 156                 object this [string name] {
 157                         get { return GetValue (GetOrdinal (name)); }
 158                 }
 159
 160                 public
 161 #if NET_2_0
 162                 override
 163 #endif // NET_2_0
 164                 int RecordsAffected {
 165                         get {
 166                                 return command.Tds.RecordsAffected;
 167                         }
 168                 }
 169
 170                 public
 171 #if NET_2_0
 172                 override
 173 #endif // NET_2_0
 174                 bool HasRows {
 175                         get {
 176                                 if (haveRead)
 177                                         return readResult;
 178
 179                                 haveRead = true;
 180                                 readResult = ReadRecord ();
 181                                 return readResult;
 182                         }
 183                 }
 184 #if NET_2_0
 185                 public override int VisibleFieldCount {
 186                         get { return visibleFieldCount; }
 187                 }
 188
 189                 protected SqlConnection Connection {
 190                         get { return command.Connection; }
 191                 }
 192
 193                 protected bool IsCommandBehavior (CommandBehavior condition) {
 194                         return condition == command.CommandBehavior;
 195                 }
 196 #endif
 197
 198                 #endregion // Properties
 199
 200                 #region Methods
 201
 202                 public
 203 #if NET_2_0
 204                 override
 205 #endif // NET_2_0
 206                 void Close ()
 207                 {
 208                         if (IsClosed)
 209                                 return;
 210                         // skip to end & read output parameters.
 211                         while (NextResult ())
 212                                 ;
 213                         isClosed = true;
 214                         command.CloseDataReader ();
 215                 }
 216
 217                 private static DataTable ConstructSchemaTable ()
 218                 {
 219                         Type booleanType = typeof (bool);
 220                         Type stringType = typeof (string);
 221                         Type intType = typeof (int);
 222                         Type typeType = typeof (Type);
 223                         Type shortType = typeof (short);
 224
 225                         DataTable schemaTable = new DataTable ("SchemaTable");
 226                         schemaTable.Columns.Add ("ColumnName", stringType);
 227                         schemaTable.Columns.Add ("ColumnOrdinal", intType);
 228                         schemaTable.Columns.Add ("ColumnSize", intType);
 229                         schemaTable.Columns.Add ("NumericPrecision", shortType);
 230                         schemaTable.Columns.Add ("NumericScale", shortType);
 231                         schemaTable.Columns.Add ("IsUnique", booleanType);
 232                         schemaTable.Columns.Add ("IsKey", booleanType);
 233                         schemaTable.Columns.Add ("BaseServerName", stringType);
 234                         schemaTable.Columns.Add ("BaseCatalogName", stringType);
 235                         schemaTable.Columns.Add ("BaseColumnName", stringType);
 236                         schemaTable.Columns.Add ("BaseSchemaName", stringType);
 237                         schemaTable.Columns.Add ("BaseTableName", stringType);
 238                         schemaTable.Columns.Add ("DataType", typeType);
 239                         schemaTable.Columns.Add ("AllowDBNull", booleanType);
 240                         schemaTable.Columns.Add ("ProviderType", intType);
 241                         schemaTable.Columns.Add ("IsAliased", booleanType);
 242                         schemaTable.Columns.Add ("IsExpression", booleanType);
 243                         schemaTable.Columns.Add ("IsIdentity", booleanType);
 244                         schemaTable.Columns.Add ("IsAutoIncrement", booleanType);
 245                         schemaTable.Columns.Add ("IsRowVersion", booleanType);
 246                         schemaTable.Columns.Add ("IsHidden", booleanType);
 247                         schemaTable.Columns.Add ("IsLong", booleanType);
 248                         schemaTable.Columns.Add ("IsReadOnly", booleanType);
 249
 250                         return schemaTable;
 251                 }
 252
 253                 private void GetSchemaRowTypeName (TdsColumnType ctype, int csize, out string typeName)
 254                 {
 255                         int dbType;
 256                         bool isLong;
 257                         Type fieldType;
 258
 259                         GetSchemaRowType (ctype, csize, out dbType, out fieldType, out isLong, out typeName);
 260                 }
 261
 262                 private void GetSchemaRowFieldType (TdsColumnType ctype, int csize, out Type fieldType)
 263                 {
 264                         int dbType;
 265                         bool isLong;
 266                         string typeName;
 267
 268                         GetSchemaRowType (ctype, csize, out dbType, out fieldType, out isLong, out typeName);
 269                 }
 270
 271                 private void GetSchemaRowDbType (TdsColumnType ctype, int csize, out int dbType)
 272                 {
 273                         Type fieldType;
 274                         bool isLong;
 275                         string typeName;
 276
 277                         GetSchemaRowType (ctype, csize, out dbType, out fieldType, out isLong, out typeName);
 278                 }
 279
 280                 private void GetSchemaRowType (TdsColumnType ctype, int csize,
 281                                                out int dbType, out Type fieldType,
 282                                                out bool isLong, out string typeName)
 283                 {
 284                         dbType = -1;
 285                         typeName = string.Empty;
 286                         isLong = false;
 287                         fieldType = typeof (Type);
 288
 289                         switch (ctype) {
 290                                 case TdsColumnType.Int1:
 291                                 case TdsColumnType.Int2:
 292                                 case TdsColumnType.Int4:
 293                                 case TdsColumnType.IntN:
 294                                         switch (csize) {
 295                                         case 1:
 296                                                 typeName = "tinyint";
 297                                                 dbType = (int) SqlDbType.TinyInt;
 298                                                 fieldType = typeof (byte);
 299                                                 isLong = false;
 300                                                 break;
 301                                         case 2:
 302                                                 typeName = "smallint";
 303                                                 dbType = (int) SqlDbType.SmallInt;
 304                                                 fieldType = typeof (short);
 305                                                 isLong = false;
 306                                                 break;
 307                                         case 4:
 308                                                 typeName = "int";
 309                                                 dbType = (int) SqlDbType.Int;
 310                                                 fieldType = typeof (int);
 311                                                 isLong = false;
 312                                                 break;
 313                                         case 8:
 314                                                 typeName = "bigint";
 315                                                 dbType = (int) SqlDbType.BigInt;
 316                                                 fieldType = typeof (long);
 317                                                 isLong = false;
 318                                                 break;
 319                                         }
 320                                         break;
 321                                 case TdsColumnType.Real:
 322                                 case TdsColumnType.Float8:
 323                                 case TdsColumnType.FloatN:
 324                                         switch (csize) {
 325                                         case 4:
 326                                                 typeName = "real";
 327                                                 dbType = (int) SqlDbType.Real;
 328                                                 fieldType = typeof (float);
 329                                                 isLong = false;
 330                                                 break;
 331                                         case 8:
 332                                                 typeName = "float";
 333                                                 dbType = (int) SqlDbType.Float;
 334                                                 fieldType = typeof (double);
 335                                                 isLong = false;
 336                                                 break;
 337                                         }
 338                                         break;
 339                                 case TdsColumnType.Image :
 340                                         typeName = "image";
 341                                         dbType = (int) SqlDbType.Image;
 342                                         fieldType = typeof (byte[]);
 343                                         isLong = true;
 344                                         break;
 345                                 case TdsColumnType.Text :
 346                                         typeName = "text";
 347                                         dbType = (int) SqlDbType.Text;
 348                                         fieldType = typeof (string);
 349                                         isLong = true;
 350                                         break;
 351                                 case TdsColumnType.UniqueIdentifier :
 352                                         typeName = "uniqueidentifier";
 353                                         dbType = (int) SqlDbType.UniqueIdentifier;
 354                                         fieldType = typeof (Guid);
 355                                         isLong = false;
 356                                         break;
 357                                 case TdsColumnType.VarBinary :
 358                                 case TdsColumnType.BigVarBinary :
 359                                         typeName = "varbinary";
 360                                         dbType = (int) SqlDbType.VarBinary;
 361                                         fieldType = typeof (byte[]);
 362                                         isLong = true;
 363                                         break;
 364                                 case TdsColumnType.VarChar :
 365                                 case TdsColumnType.BigVarChar :
 366                                         typeName = "varchar";
 367                                         dbType = (int) SqlDbType.VarChar;
 368                                         fieldType = typeof (string);
 369                                         isLong = false;
 370                                         break;
 371                                 case TdsColumnType.Binary :
 372                                 case TdsColumnType.BigBinary :
 373                                         typeName = "binary";
 374                                         dbType = (int) SqlDbType.Binary;
 375                                         fieldType = typeof (byte[]);
 376                                         isLong = true;
 377                                         break;
 378                                 case TdsColumnType.Char :
 379                                 case TdsColumnType.BigChar :
 380                                         typeName = "char";
 381                                         dbType = (int) SqlDbType.Char;
 382                                         fieldType = typeof (string);
 383                                         isLong = false;
 384                                         break;
 385                                 case TdsColumnType.Bit :
 386                                 case TdsColumnType.BitN :
 387                                         typeName = "bit";
 388                                         dbType = (int) SqlDbType.Bit;
 389                                         fieldType = typeof (bool);
 390                                         isLong = false;
 391                                         break;
 392                                 case TdsColumnType.DateTime4 :
 393                                 case TdsColumnType.DateTime :
 394                                 case TdsColumnType.DateTimeN :
 395                                         typeName = "datetime";
 396                                         dbType = (int) SqlDbType.DateTime;
 397                                         fieldType = typeof (DateTime);
 398                                         isLong = false;
 399                                         break;
 400                                 case TdsColumnType.Money :
 401                                 case TdsColumnType.MoneyN :
 402                                 case TdsColumnType.Money4 :
 403                                         typeName = "money";
 404                                         dbType = (int) SqlDbType.Money;
 405                                         fieldType = typeof (decimal);
 406                                         isLong = false;
 407                                         break;
 408                                 case TdsColumnType.NText :
 409                                         typeName = "ntext";
 410                                         dbType = (int) SqlDbType.NText;
 411                                         fieldType = typeof (string);
 412                                         isLong = true;
 413                                         break;
 414                                 case TdsColumnType.NVarChar :
 415                                         typeName = "nvarchar";
 416                                         dbType = (int) SqlDbType.NVarChar;
 417                                         fieldType = typeof (string);
 418                                         isLong = false;
 419                                         break;
 420                                 case TdsColumnType.Decimal :
 421                                 case TdsColumnType.Numeric :
 422                                         typeName = "decimal";
 423                                         dbType = (int) SqlDbType.Decimal;
 424                                         fieldType = typeof (decimal);
 425                                         isLong = false;
 426                                         break;
 427                                 case TdsColumnType.NChar :
 428                                         typeName = "nchar";
 429                                         dbType = (int) SqlDbType.NChar;
 430                                         fieldType = typeof (string);
 431                                         isLong = false;
 432                                         break;
 433                                 case TdsColumnType.SmallMoney :
 434                                         typeName = "smallmoney";
 435                                         dbType = (int) SqlDbType.SmallMoney;
 436                                         fieldType = typeof (decimal);
 437                                         isLong = false;
 438                                         break;
 439                                 default :
 440                                         typeName = "variant";
 441                                         dbType = (int) SqlDbType.Variant;
 442                                         fieldType = typeof (object);
 443                                         isLong = false;
 444                                         break;
 445                         }
 446                 }
 447
 448 #if NET_2_0
 449                 new
 450 #endif
 451                 void Dispose (bool disposing)
 452                 {
 453                         if (!disposed) {
 454                                 if (disposing) {
 455                                         if (schemaTable != null)
 456                                                 schemaTable.Dispose ();
 457                                         Close ();
 458                                         command = null;
 459                                 }
 460                                 disposed = true;
 461                         }
 462                 }
 463
 464                 public
 465 #if NET_2_0
 466                 override
 467 #endif // NET_2_0
 468                 bool GetBoolean (int i)
 469                 {
 470                         object value = GetValue (i);
 471                         if (!(value is bool)) {
 472                                 if (value is DBNull) throw new SqlNullValueException ();
 473                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 474                         }
 475                         return (bool) value;
 476                 }
 477
 478                 public
 479 #if NET_2_0
 480                 override
 481 #endif // NET_2_0
 482                 byte GetByte (int i)
 483                 {
 484                         object value = GetValue (i);
 485                         if (!(value is byte)) {
 486                                 if (value is DBNull) throw new SqlNullValueException ();
 487                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 488                         }
 489                         return (byte) value;
 490                 }
 491
 492                 public
 493 #if NET_2_0
 494                 override
 495 #endif // NET_2_0
 496                 long GetBytes (int i, long dataIndex, byte[] buffer, int bufferIndex, int length)
 497                 {
 498                         if ((command.CommandBehavior & CommandBehavior.SequentialAccess) != 0) {
 499                                 try {
 500                                         long len = ((Tds)command.Tds).GetSequentialColumnValue (i, dataIndex, buffer, bufferIndex, length);
 501                                         if (len == -1)
 502                                                 throw new InvalidCastException ("Invalid attempt to GetBytes on column "
 503                                                                                 + "'" + command.Tds.Columns[i]["ColumnName"] +
 504                                                                                 "'." + "The GetBytes function"
 505                                                                                 + " can only be used on columns of type Text, NText, or Image");
 506                                         return len;
 507                                 } catch (TdsInternalException ex) {
 508                                         command.Connection.Close ();
 509                                         throw SqlException.FromTdsInternalException ((TdsInternalException) ex);
 510                                 }
 511                         }
 512
 513                         object value = GetValue (i);
 514                         if (!(value is byte [])) {
 515                                 if (value is DBNull) throw new SqlNullValueException ();
 516                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 517                         }
 518
 519                         if ( buffer == null )
 520                                 return ((byte []) value).Length; // Return length of data
 521
 522                         // Copy data into buffer
 523                         int availLen = (int) ( ( (byte []) value).Length - dataIndex);
 524                         if (availLen < length)
 525                                 length = availLen;
 526                         Array.Copy ((byte []) value, (int) dataIndex, buffer, bufferIndex, length);
 527                         return length; // return actual read count
 528                 }
 529
 530                 [EditorBrowsableAttribute (EditorBrowsableState.Never)]
 531                 public
 532 #if NET_2_0
 533                 override
 534 #endif // NET_2_0
 535                 char GetChar (int i)
 536                 {
 537                         object value = GetValue (i);
 538                         if (!(value is char)) {
 539                                 if (value is DBNull) throw new SqlNullValueException ();
 540                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 541                         }
 542                         return (char) value;
 543                 }
 544
 545                 public
 546 #if NET_2_0
 547                 override
 548 #endif // NET_2_0
 549                 long GetChars (int i, long dataIndex, char[] buffer, int bufferIndex, int length)
 550                 {
 551                         if ((command.CommandBehavior & CommandBehavior.SequentialAccess) != 0) {
 552                                 Encoding encoding = null;
 553                                 byte mul = 1;
 554                                 TdsColumnType colType = (TdsColumnType) command.Tds.Columns[i]["ColumnType"];
 555                                 switch (colType) {
 556                                         case TdsColumnType.Text :
 557                                         case TdsColumnType.VarChar:
 558                                         case TdsColumnType.Char:
 559                                         case TdsColumnType.BigVarChar:
 560                                                 encoding = Encoding.ASCII;
 561                                                 break;
 562                                         case TdsColumnType.NText :
 563                                         case TdsColumnType.NVarChar:
 564                                         case TdsColumnType.NChar:
 565                                                 encoding = Encoding.Unicode;
 566                                                 mul = 2;
 567                                                 break;
 568                                         default :
 569                                                 return -1;
 570                                 }
 571
 572                                 long count = 0;
 573                                 if (buffer == null) {
 574                                         count = GetBytes (i,0,(byte[]) null,0,0);
 575                                         return (count/mul);
 576                                 }
 577
 578                                 length *= mul;
 579                                 byte[] arr = new byte [length];
 580                                 count = GetBytes (i, dataIndex, arr, 0, length);
 581                                 if (count == -1)
 582                                         throw new InvalidCastException ("Specified cast is not valid");
 583
 584                                 Char[] val = encoding.GetChars (arr, 0, (int)count);
 585                                 val.CopyTo (buffer, bufferIndex);
 586                                 return val.Length;
 587                         }
 588
 589                         char [] valueBuffer;
 590                         object value = GetValue (i);
 591
 592                         if (value is char[])
 593                                 valueBuffer = (char[])value;
 594                         else if (value is string)
 595                                 valueBuffer = ((string)value).ToCharArray();
 596                         else {
 597                                 if (value is DBNull) throw new SqlNullValueException ();
 598                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 599                         }
 600
 601                         if ( buffer == null ) {
 602                                 // Return length of data
 603                                 return valueBuffer.Length;
 604                         }
 605                         else {
 606                                 // Copy data into buffer
 607                                 Array.Copy (valueBuffer, (int) dataIndex, buffer, bufferIndex, length);
 608                                 return valueBuffer.Length - dataIndex;
 609                         }
 610                 }
 611
 612 #if !NET_2_0
 613                 [EditorBrowsableAttribute (EditorBrowsableState.Never)]
 614                 public new IDataReader GetData (int i)
 615                 {
 616                         return ((IDataReader) this [i]);
 617                 }
 618 #endif
 619
 620                 public
 621 #if NET_2_0
 622                 override
 623 #endif // NET_2_0
 624                 string GetDataTypeName (int i)
 625                 {
 626                         TdsColumnType ctype;
 627                         string datatypeName;
 628                         int csize;
 629
 630                         if (i < 0 || i >= command.Tds.Columns.Count)
 631                                 throw new IndexOutOfRangeException ();
 632 #if NET_2_0
 633                         ctype = (TdsColumnType) command.Tds.Columns[i].ColumnType;
 634                         csize = (int) command.Tds.Columns[i].ColumnSize;
 635 #else
 636                         ctype = (TdsColumnType) command.Tds.Columns[i]["ColumnType"];
 637                         csize = (int) command.Tds.Columns[i]["ColumnSize"];
 638 #endif
 639                         GetSchemaRowTypeName (ctype, csize, out datatypeName);
 640                         return datatypeName;
 641                 }
 642
 643                 public
 644 #if NET_2_0
 645                 override
 646 #endif // NET_2_0
 647                 DateTime GetDateTime (int i)
 648                 {
 649                         object value = GetValue (i);
 650                         if (!(value is DateTime)) {
 651                                 if (value is DBNull) throw new SqlNullValueException ();
 652                                 else throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 653                         }
 654                         return (DateTime) value;
 655                 }
 656
 657                 public
 658 #if NET_2_0
 659                 override
 660 #endif // NET_2_0
 661                 decimal GetDecimal (int i)
 662                 {
 663                         object value = GetValue (i);
 664                         if (!(value is decimal)) {
 665                                 if (value is DBNull) throw new SqlNullValueException ();
 666                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 667                         }
 668                         return (decimal) value;
 669                 }
 670
 671                 public
 672 #if NET_2_0
 673                 override
 674 #endif // NET_2_0
 675                 double GetDouble (int i)
 676                 {
 677                         object value = GetValue (i);
 678                         if (!(value is double)) {
 679                                 if (value is DBNull) throw new SqlNullValueException ();
 680                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 681                         }
 682                         return (double) value;
 683                 }
 684
 685                 public
 686 #if NET_2_0
 687                 override
 688 #endif // NET_2_0
 689                 Type GetFieldType (int i)
 690                 {
 691                         TdsColumnType ctype;
 692                         Type fieldType;
 693                         int csize;
 694
 695                         if (i < 0 || i >= command.Tds.Columns.Count)
 696                                 throw new IndexOutOfRangeException ();
 697 #if NET_2_0
 698                         ctype = (TdsColumnType) command.Tds.Columns[i].ColumnType;
 699                         csize = (int) command.Tds.Columns[i].ColumnSize;
 700 #else
 701                         ctype = (TdsColumnType) command.Tds.Columns[i]["ColumnType"];
 702                         csize = (int) command.Tds.Columns[i]["ColumnSize"];
 703 #endif
 704                         GetSchemaRowFieldType (ctype, csize, out fieldType);
 705                         return fieldType;
 706                 }
 707
 708                 public
 709 #if NET_2_0
 710                 override
 711 #endif // NET_2_0
 712                 float GetFloat (int i)
 713                 {
 714                         object value = GetValue (i);
 715                         if (!(value is float)) {
 716                                 if (value is DBNull) throw new SqlNullValueException ();
 717                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 718                         }
 719                         return (float) value;
 720                 }
 721
 722                 public
 723 #if NET_2_0
 724                 override
 725 #endif // NET_2_0
 726                 Guid GetGuid (int i)
 727                 {
 728                         object value = GetValue (i);
 729                         if (!(value is Guid)) {
 730                                 if (value is DBNull) throw new SqlNullValueException ();
 731                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 732                         }
 733                         return (Guid) value;
 734                 }
 735
 736                 public
 737 #if NET_2_0
 738                 override
 739 #endif // NET_2_0
 740                 short GetInt16 (int i)
 741                 {
 742                         object value = GetValue (i);
 743                         if (!(value is short)) {
 744                                 if (value is DBNull) throw new SqlNullValueException ();
 745                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 746                         }
 747                         return (short) value;
 748                 }
 749
 750                 public
 751 #if NET_2_0
 752                 override
 753 #endif // NET_2_0
 754                 int GetInt32 (int i)
 755                 {
 756                         object value = GetValue (i);
 757                         if (!(value is int)) {
 758                                 if (value is DBNull) throw new SqlNullValueException ();
 759                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 760                         }
 761                         return (int) value;
 762                 }
 763
 764                 public
 765 #if NET_2_0
 766                 override
 767 #endif // NET_2_0
 768                 long GetInt64 (int i)
 769                 {
 770                         object value = GetValue (i);
 771                         if (!(value is long)) {
 772                                 if (value is DBNull) throw new SqlNullValueException ();
 773                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 774                         }
 775                         return (long) value;
 776                 }
 777
 778                 public
 779 #if NET_2_0
 780                 override
 781 #endif // NET_2_0
 782                 string GetName (int i)
 783                 {
 784                         if (i < 0 || i >= command.Tds.Columns.Count)
 785                                 throw new IndexOutOfRangeException ();
 786 #if NET_2_0
 787                         return (string) command.Tds.Columns[i].ColumnName;
 788 #else
 789                         return (string) command.Tds.Columns[i]["ColumnName"];
 790 #endif
 791                 }
 792
 793                 public
 794 #if NET_2_0
 795                 override
 796 #endif // NET_2_0
 797                 int GetOrdinal (string name)
 798                 {
 799                         string colName;
 800                         foreach (TdsDataColumn schema in command.Tds.Columns) {
 801 #if NET_2_0
 802                                 colName = schema.ColumnName;
 803                                 if (colName.Equals (name) || String.Compare (colName, name, true) == 0)
 804                                         return (int) schema.ColumnOrdinal;
 805 #else
 806                                 colName = (string) schema["ColumnName"];
 807                                 if (colName.Equals (name) || String.Compare (colName, name, true) == 0)
 808                                         return (int) schema["ColumnOrdinal"];
 809 #endif
 810                         }
 811                         throw new IndexOutOfRangeException ();
 812                 }
 813
 814                 public
 815 #if NET_2_0
 816                 override
 817 #endif // NET_2_0
 818                 DataTable GetSchemaTable ()
 819                 {
 820                         ValidateState ();
 821
 822                         if (schemaTable == null)
 823                                 schemaTable = ConstructSchemaTable ();
 824
 825                         if (schemaTable.Rows != null && schemaTable.Rows.Count > 0)
 826                                 return schemaTable;
 827
 828                         if (!moreResults)
 829                                 return null;
 830
 831                         dataTypeNames = new ArrayList (command.Tds.Columns.Count);
 832
 833                         foreach (TdsDataColumn schema in command.Tds.Columns) {
 834                                 DataRow row = schemaTable.NewRow ();
 835
 836 #if NET_2_0
 837                                 row [COLUMN_NAME_IDX]           = GetSchemaValue (schema.ColumnName);
 838                                 row [COLUMN_ORDINAL_IDX]                = GetSchemaValue (schema.ColumnOrdinal);
 839                                 row [IS_UNIQUE_IDX]             = GetSchemaValue (schema.IsUnique);
 840                                 row [IS_AUTO_INCREMENT_IDX]             = GetSchemaValue (schema.IsAutoIncrement);
 841                                 row [IS_ROW_VERSION_IDX]                = GetSchemaValue (schema.IsRowVersion);
 842                                 row [IS_HIDDEN_IDX]             = GetSchemaValue (schema.IsHidden);
 843                                 row [IS_IDENTITY_IDX]           = GetSchemaValue (schema.IsIdentity);
 844                                 row [COLUMN_SIZE_IDX]           = GetSchemaValue (schema.ColumnSize);
 845                                 row [NUMERIC_PRECISION_IDX]     = GetSchemaValue (schema.NumericPrecision);
 846                                 row [NUMERIC_SCALE_IDX]         = GetSchemaValue (schema.NumericScale);
 847                                 row [IS_KEY_IDX]                        = GetSchemaValue (schema.IsKey);
 848                                 row [IS_ALIASED_IDX]            = GetSchemaValue (schema.IsAliased);
 849                                 row [IS_EXPRESSION_IDX]         = GetSchemaValue (schema.IsExpression);
 850                                 row [IS_READ_ONLY_IDX]          = GetSchemaValue (schema.IsReadOnly);
 851                                 row [BASE_SERVER_NAME_IDX]              = GetSchemaValue (schema.BaseServerName);
 852                                 row [BASE_CATALOG_NAME_IDX]             = GetSchemaValue (schema.BaseCatalogName);
 853                                 row [BASE_COLUMN_NAME_IDX]              = GetSchemaValue (schema.BaseColumnName);
 854                                 row [BASE_SCHEMA_NAME_IDX]              = GetSchemaValue (schema.BaseSchemaName);
 855                                 row [BASE_TABLE_NAME_IDX]               = GetSchemaValue (schema.BaseTableName);
 856                                 row [ALLOW_DBNULL_IDX]          = GetSchemaValue (schema.AllowDBNull);
 857 #else
 858                                 row ["ColumnName"]              = GetSchemaValue (schema, "ColumnName");
 859                                 row ["ColumnOrdinal"]           = GetSchemaValue (schema, "ColumnOrdinal");
 860                                 row ["IsUnique"]                = GetSchemaValue (schema, "IsUnique");
 861                                 row ["IsAutoIncrement"]         = GetSchemaValue (schema, "IsAutoIncrement");
 862                                 row ["IsRowVersion"]            = GetSchemaValue (schema, "IsRowVersion");
 863                                 row ["IsHidden"]                = GetSchemaValue (schema, "IsHidden");
 864                                 row ["IsIdentity"]              = GetSchemaValue (schema, "IsIdentity");
 865                                 row ["ColumnSize"]              = GetSchemaValue (schema, "ColumnSize");
 866                                 row ["NumericPrecision"]        = GetSchemaValue (schema, "NumericPrecision");
 867                                 row ["NumericScale"]            = GetSchemaValue (schema, "NumericScale");
 868                                 row ["IsKey"]                   = GetSchemaValue (schema, "IsKey");
 869                                 row ["IsAliased"]               = GetSchemaValue (schema, "IsAliased");
 870                                 row ["IsExpression"]            = GetSchemaValue (schema, "IsExpression");
 871                                 row ["IsReadOnly"]              = GetSchemaValue (schema, "IsReadOnly");
 872                                 row ["BaseServerName"]          = GetSchemaValue (schema, "BaseServerName");
 873                                 row ["BaseCatalogName"]         = GetSchemaValue (schema, "BaseCatalogName");
 874                                 row ["BaseColumnName"]          = GetSchemaValue (schema, "BaseColumnName");
 875                                 row ["BaseSchemaName"]          = GetSchemaValue (schema, "BaseSchemaName");
 876                                 row ["BaseTableName"]           = GetSchemaValue (schema, "BaseTableName");
 877                                 row ["AllowDBNull"]             = GetSchemaValue (schema, "AllowDBNull");
 878 #endif
 879                                 // We don't always get the base column name.
 880                                 if (row [BASE_COLUMN_NAME_IDX] == DBNull.Value)
 881                                         row [BASE_COLUMN_NAME_IDX] = row [COLUMN_NAME_IDX];
 882
 883                                 TdsColumnType ctype;
 884                                 int csize, dbType;
 885                                 Type fieldType;
 886                                 bool isLong;
 887                                 string typeName;
 888 #if NET_2_0
 889                                 ctype = (TdsColumnType) schema.ColumnType;
 890                                 csize = (int) schema.ColumnSize;
 891 #else
 892                                 ctype = (TdsColumnType) schema ["ColumnType"];
 893                                 csize = (int) schema ["ColumnSize"];
 894 #endif
 895
 896                                 GetSchemaRowType (ctype, csize, out dbType,
 897                                                                         out fieldType, out isLong, out typeName);
 898
 899                                 dataTypeNames.Add (typeName);
 900                                 row [PROVIDER_TYPE_IDX] = dbType;
 901                                 row [DATA_TYPE_IDX] = fieldType;
 902                                 row [IS_LONG_IDX] = isLong;
 903 #if NET_2_0
 904                                 if ((bool)row [IS_HIDDEN_IDX] == false)
 905                                         visibleFieldCount += 1;
 906 #endif
 907
 908                                 schemaTable.Rows.Add (row);
 909                         }
 910                         return schemaTable;
 911                 }
 912
 913                 private static object GetSchemaValue (TdsDataColumn schema, string key)
 914                 {
 915                         object val = schema [key];
 916                         if (val != null)
 917                                 return val;
 918                         else
 919                                 return DBNull.Value;
 920                 }
 921
 922                 static object GetSchemaValue (object value)
 923                 {
 924                         if (value == null)
 925                                 return DBNull.Value;
 926
 927                         return value;
 928                 }
 929
 930                 public
 931 #if NET_2_0
 932                 virtual
 933 #endif
 934                 SqlBinary GetSqlBinary (int i)
 935                 {
 936                         object value = GetSqlValue (i);
 937                         if (!(value is SqlBinary))
 938                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 939                         return (SqlBinary) value;
 940                 }
 941
 942                 public
 943 #if NET_2_0
 944                 virtual
 945 #endif
 946                 SqlBoolean GetSqlBoolean (int i)
 947                 {
 948                         object value = GetSqlValue (i);
 949                         if (!(value is SqlBoolean))
 950                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 951                         return (SqlBoolean) value;
 952                 }
 953
 954                 public
 955 #if NET_2_0
 956                 virtual
 957 #endif
 958                 SqlByte GetSqlByte (int i)
 959                 {
 960                         object value = GetSqlValue (i);
 961                         if (!(value is SqlByte))
 962                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 963                         return (SqlByte) value;
 964                 }
 965
 966                 public
 967 #if NET_2_0
 968                 virtual
 969 #endif
 970                 SqlDateTime GetSqlDateTime (int i)
 971                 {
 972                         object value = GetSqlValue (i);
 973                         if (!(value is SqlDateTime))
 974                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 975                         return (SqlDateTime) value;
 976                 }
 977
 978                 public
 979 #if NET_2_0
 980                 virtual
 981 #endif
 982                 SqlDecimal GetSqlDecimal (int i)
 983                 {
 984                         object value = GetSqlValue (i);
 985                         if (!(value is SqlDecimal))
 986                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 987                         return (SqlDecimal) value;
 988                 }
 989
 990                 public
 991 #if NET_2_0
 992                 virtual
 993 #endif
 994                 SqlDouble GetSqlDouble (int i)
 995                 {
 996                         object value = GetSqlValue (i);
 997                         if (!(value is SqlDouble))
 998                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
 999                         return (SqlDouble) value;
1000                 }
1001
1002                 public
1003 #if NET_2_0
1004                 virtual
1005 #endif
1006                 SqlGuid GetSqlGuid (int i)
1007                 {
1008                         object value = GetSqlValue (i);
1009                         if (!(value is SqlGuid))
1010                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1011                         return (SqlGuid) value;
1012                 }
1013
1014                 public
1015 #if NET_2_0
1016                 virtual
1017 #endif
1018                 SqlInt16 GetSqlInt16 (int i)
1019                 {
1020                         object value = GetSqlValue (i);
1021                         if (!(value is SqlInt16))
1022                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1023                         return (SqlInt16) value;
1024                 }
1025
1026                 public
1027 #if NET_2_0
1028                 virtual
1029 #endif
1030                 SqlInt32 GetSqlInt32 (int i)
1031                 {
1032                         object value = GetSqlValue (i);
1033                         if (!(value is SqlInt32))
1034                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1035                         return (SqlInt32) value;
1036                 }
1037
1038                 public
1039 #if NET_2_0
1040                 virtual
1041 #endif
1042                 SqlInt64 GetSqlInt64 (int i)
1043                 {
1044                         object value = GetSqlValue (i);
1045                         // TDS 7.0 returns bigint as decimal(19,0)
1046                         if (value is SqlDecimal) {
1047                                 TdsDataColumn schema = command.Tds.Columns[i];
1048                                 byte precision, scale;
1049
1050 #if NET_2_0
1051                                 precision = (byte)schema.NumericPrecision;
1052                                 scale = (byte)schema.NumericScale;
1053 #else
1054                                 precision = (byte)schema["NumericPrecision"];
1055                                 scale = (byte)schema["NumericScale"];
1056 #endif
1057                                 if (precision == 19 && scale == 0)
1058                                         value = (SqlInt64) (SqlDecimal) value;
1059                         }
1060                         if (!(value is SqlInt64))
1061                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1062                         return (SqlInt64) value;
1063                 }
1064
1065                 public
1066 #if NET_2_0
1067                 virtual
1068 #endif
1069                 SqlMoney GetSqlMoney (int i)
1070                 {
1071                         object value = GetSqlValue (i);
1072                         if (!(value is SqlMoney))
1073                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1074                         return (SqlMoney) value;
1075                 }
1076
1077                 public
1078 #if NET_2_0
1079                 virtual
1080 #endif
1081                 SqlSingle GetSqlSingle (int i)
1082                 {
1083                         object value = GetSqlValue (i);
1084                         if (!(value is SqlSingle))
1085                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1086                         return (SqlSingle) value;
1087                 }
1088
1089                 public
1090 #if NET_2_0
1091                 virtual
1092 #endif
1093                 SqlString GetSqlString (int i)
1094                 {
1095                         object value = GetSqlValue (i);
1096                         if (!(value is SqlString))
1097                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1098                         return (SqlString) value;
1099                 }
1100
1101 #if NET_2_0
1102                 public virtual SqlXml GetSqlXml (int i)
1103                 {
1104                         object value = GetSqlValue (i);
1105                         if (!(value is SqlXml)) {
1106                                 if (value is DBNull) throw new SqlNullValueException ();
1107                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1108                         }
1109                         return (SqlXml) value;
1110                 }
1111 #endif // NET_2_0
1112
1113                 public
1114 #if NET_2_0
1115                 virtual
1116 #endif
1117                 object GetSqlValue (int i)
1118                 {
1119                         int dbType, csize;
1120                         TdsColumnType ctype;
1121
1122                         if (i < 0 || i >= command.Tds.Columns.Count)
1123                                 throw new IndexOutOfRangeException ();
1124 #if NET_2_0
1125                         ctype = (TdsColumnType) command.Tds.Columns[i].ColumnType;
1126                         csize = (int) command.Tds.Columns[i].ColumnSize;
1127 #else
1128                         ctype = (TdsColumnType) command.Tds.Columns[i]["ColumnType"];
1129                         csize = (int) command.Tds.Columns[i]["ColumnSize"];
1130 #endif
1131                         GetSchemaRowDbType (ctype, csize, out dbType);
1132                         SqlDbType type = (SqlDbType) dbType;
1133                         object value = GetValue (i);
1134
1135                         switch (type) {
1136                         case SqlDbType.BigInt:
1137                                 if (value == DBNull.Value)
1138                                         return SqlInt64.Null;
1139                                 return (SqlInt64) ((long) value);
1140                         case SqlDbType.Binary:
1141                         case SqlDbType.Image:
1142                         case SqlDbType.VarBinary:
1143                         case SqlDbType.Timestamp:
1144                                 if (value == DBNull.Value)
1145                                         return SqlBinary.Null;
1146                                 return (SqlBinary) ((byte[]) value);
1147                         case SqlDbType.Bit:
1148                                 if (value == DBNull.Value)
1149                                         return SqlBoolean.Null;
1150                                 return (SqlBoolean) ((bool) value);
1151                         case SqlDbType.Char:
1152                         case SqlDbType.NChar:
1153                         case SqlDbType.NText:
1154                         case SqlDbType.NVarChar:
1155                         case SqlDbType.Text:
1156                         case SqlDbType.VarChar:
1157                                 if (value == DBNull.Value)
1158                                         return SqlString.Null;
1159                                 return (SqlString) ((string) value);
1160                         case SqlDbType.DateTime:
1161                         case SqlDbType.SmallDateTime:
1162                                 if (value == DBNull.Value)
1163                                         return SqlDateTime.Null;
1164                                 return (SqlDateTime) ((DateTime) value);
1165                         case SqlDbType.Decimal:
1166                                 if (value == DBNull.Value)
1167                                         return SqlDecimal.Null;
1168                                 if (value is TdsBigDecimal)
1169                                         return SqlDecimal.FromTdsBigDecimal ((TdsBigDecimal) value);
1170                                 return (SqlDecimal) ((decimal) value);
1171                         case SqlDbType.Float:
1172                                 if (value == DBNull.Value)
1173                                         return SqlDouble.Null;
1174                                 return (SqlDouble) ((double) value);
1175                         case SqlDbType.Int:
1176                                 if (value == DBNull.Value)
1177                                         return SqlInt32.Null;
1178                                 return (SqlInt32) ((int) value);
1179                         case SqlDbType.Money:
1180                         case SqlDbType.SmallMoney:
1181                                 if (value == DBNull.Value)
1182                                         return SqlMoney.Null;
1183                                 return (SqlMoney) ((decimal) value);
1184                         case SqlDbType.Real:
1185                                 if (value == DBNull.Value)
1186                                         return SqlSingle.Null;
1187                                 return (SqlSingle) ((float) value);
1188                         case SqlDbType.UniqueIdentifier:
1189                                 if (value == DBNull.Value)
1190                                         return SqlGuid.Null;
1191                                 return (SqlGuid) ((Guid) value);
1192                         case SqlDbType.SmallInt:
1193                                 if (value == DBNull.Value)
1194                                         return SqlInt16.Null;
1195                                 return (SqlInt16) ((short) value);
1196                         case SqlDbType.TinyInt:
1197                                 if (value == DBNull.Value)
1198                                         return SqlByte.Null;
1199                                 return (SqlByte) ((byte) value);
1200 #if NET_2_0
1201                         case SqlDbType.Xml:
1202                                 if (value == DBNull.Value)
1203                                         return SqlByte.Null;
1204                                 return (SqlXml) value;
1205 #endif
1206                         }
1207
1208                         throw new InvalidOperationException ("The type of this column is unknown.");
1209                 }
1210
1211                 public
1212 #if NET_2_0
1213                 virtual
1214 #endif
1215                 int GetSqlValues (object[] values)
1216                 {
1217                         int count = 0;
1218                         int columnCount = command.Tds.Columns.Count;
1219                         int arrayCount = values.Length;
1220
1221                         if (arrayCount > columnCount)
1222                                 count = columnCount;
1223                         else
1224                                 count = arrayCount;
1225
1226                         for (int i = 0; i < count; i += 1)
1227                                 values [i] = GetSqlValue (i);
1228
1229                         return count;
1230                 }
1231
1232                 public
1233 #if NET_2_0
1234                 override
1235 #endif // NET_2_0
1236                 string GetString (int i)
1237                 {
1238                         object value = GetValue (i);
1239                         if (!(value is string)) {
1240                                 if (value is DBNull) throw new SqlNullValueException ();
1241                                 throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1242                         }
1243                         return (string) value;
1244                 }
1245
1246                 public
1247 #if NET_2_0
1248                 override
1249 #endif // NET_2_0
1250                 object GetValue (int i)
1251                 {
1252                         if (i < 0 || i >= command.Tds.Columns.Count)
1253                                 throw new IndexOutOfRangeException ();
1254
1255                         try {
1256                                 if ((command.CommandBehavior & CommandBehavior.SequentialAccess) != 0) {
1257                                         return ((Tds)command.Tds).GetSequentialColumnValue (i);
1258                                 }
1259                         } catch (TdsInternalException ex) {
1260                                 command.Connection.Close ();
1261                                 throw SqlException.FromTdsInternalException ((TdsInternalException) ex);
1262                         }
1263
1264                         return command.Tds.ColumnValues [i];
1265                 }
1266
1267                 public
1268 #if NET_2_0
1269                 override
1270 #endif // NET_2_0
1271                 int GetValues (object[] values)
1272                 {
1273                         int len = values.Length;
1274                         int bigDecimalIndex = command.Tds.ColumnValues.BigDecimalIndex;
1275
1276                         // If a four-byte decimal is stored, then we can't convert to
1277                         // a native type.  Throw an OverflowException.
1278                         if (bigDecimalIndex >= 0 && bigDecimalIndex < len)
1279                                 throw new OverflowException ();
1280                         try {
1281                                 command.Tds.ColumnValues.CopyTo (0, values, 0,
1282                                                                  len > command.Tds.ColumnValues.Count ? command.Tds.ColumnValues.Count : len);
1283                         } catch (TdsInternalException ex) {
1284                                 command.Connection.Close ();
1285                                 throw SqlException.FromTdsInternalException ((TdsInternalException) ex);
1286                         }
1287                         return (len < FieldCount ? len : FieldCount);
1288                 }
1289
1290 #if !NET_2_0
1291                 void IDisposable.Dispose ()
1292                 {
1293                         Dispose (true);
1294                         GC.SuppressFinalize (this);
1295                 }
1296 #endif
1297
1298 #if NET_2_0
1299                 public override IEnumerator GetEnumerator ()
1300 #else
1301                 IEnumerator IEnumerable.GetEnumerator ()
1302 #endif
1303                 {
1304                         return new DbEnumerator (this);
1305                 }
1306
1307                 public
1308 #if NET_2_0
1309                 override
1310 #endif // NET_2_0
1311                 bool IsDBNull (int i)
1312                 {
1313                         return GetValue (i) == DBNull.Value;
1314                 }
1315
1316                 public
1317 #if NET_2_0
1318                 override
1319 #endif // NET_2_0
1320                 bool NextResult ()
1321                 {
1322                         ValidateState ();
1323
1324                         if ((command.CommandBehavior & CommandBehavior.SingleResult) != 0 && resultsRead > 0)
1325                                 return false;
1326
1327                         try {
1328                                 moreResults = command.Tds.NextResult ();
1329                         } catch (TdsInternalException ex) {
1330                                 command.Connection.Close ();
1331                                 throw SqlException.FromTdsInternalException ((TdsInternalException) ex);
1332                         }
1333                         if (!moreResults)
1334                                 command.GetOutputParameters ();
1335                         else {
1336                                 // new schema - don't do anything except reset schemaTable as command.Tds.Columns is already updated
1337                                 schemaTable = null;
1338                                 dataTypeNames = null;
1339                         }
1340
1341                         rowsRead = 0;
1342                         resultsRead += 1;
1343                         return moreResults;
1344                 }
1345
1346                 public
1347 #if NET_2_0
1348                 override
1349 #endif // NET_2_0
1350                 bool Read ()
1351                 {
1352                         ValidateState ();
1353
1354                         if ((command.CommandBehavior & CommandBehavior.SingleRow) != 0 && rowsRead > 0)
1355                                 return false;
1356                         if ((command.CommandBehavior & CommandBehavior.SchemaOnly) != 0)
1357                                 return false;
1358                         if (!moreResults)
1359                                 return false;
1360
1361                         if ((haveRead) && (!readResultUsed))
1362                         {
1363                                 readResultUsed = true;
1364                                 return true;
1365                         }
1366                         return (ReadRecord ());
1367                 }
1368
1369                 internal bool ReadRecord ()
1370                 {
1371                         try {
1372                                 bool result = command.Tds.NextRow ();
1373
1374                                 rowsRead += 1;
1375                                 return result;
1376                         } catch (TdsInternalException ex) {
1377                                 command.Connection.Close ();
1378                                 throw SqlException.FromTdsInternalException ((TdsInternalException) ex);
1379                         }
1380                 }
1381
1382                 void ValidateState ()
1383                 {
1384                         if (IsClosed)
1385                                 throw new InvalidOperationException ("Invalid attempt to read data when reader is closed");
1386                 }
1387
1388 #if NET_2_0
1389                 public override Type GetProviderSpecificFieldType (int i)
1390                 {
1391                         return (GetSqlValue (i).GetType());
1392                 }
1393
1394                 public override object GetProviderSpecificValue (int i)
1395                 {
1396                         return (GetSqlValue (i));
1397                 }
1398
1399                 public override int GetProviderSpecificValues (object [] values)
1400                 {
1401                         return (GetSqlValues (values));
1402                 }
1403
1404                 public virtual SqlBytes GetSqlBytes (int i)
1405                 {
1406                         //object value = GetSqlValue (i);
1407                         //if (!(value is SqlBinary))
1408                         //      throw new InvalidCastException ("Type is " + value.GetType ().ToString ());
1409                         Byte[] val = (byte[])GetValue(i);
1410                         SqlBytes sb = new SqlBytes (val);
1411                         return (sb);
1412                 }
1413 #endif // NET_2_0
1414
1415                 #endregion // Methods
1416         }
1417 }