mcs/class/System.Data.OracleClient/System.Data.OracleClient/OracleDataReader.cs

   1 //
   2 // OracleDataReader.cs
   3 //
   4 // Part of the Mono class libraries at
   5 // mcs/class/System.Data.OracleClient/System.Data.OracleClient
   6 //
   7 // Assembly: System.Data.OracleClient.dll
   8 // Namespace: System.Data.OracleClient
   9 //
  10 // Authors: Tim Coleman <tim@timcoleman.com>
  11 //          Daniel Morgan <danmorg@sc.rr.com>
  12 //
  13 // Copyright (C) Tim Coleman, 2003
  14 // Copyright (C) Daniel Morgan, 2003, 2005
  15 //
  16 // Licensed under the MIT/X11 License.
  17 //
  18
  19 using System;
  20 using System.Collections;
  21 using System.Collections.Specialized;
  22 using System.ComponentModel;
  23 using System.Data;
  24 using System.Data.Common;
  25 using System.Data.OracleClient.Oci;
  26 using System.Globalization;
  27 using System.Runtime.InteropServices;
  28 using System.Text;
  29
  30 namespace System.Data.OracleClient
  31 {
  32         public sealed class OracleDataReader :
  33 #if NET_2_0
  34                 DbDataReader
  35 #else
  36                 MarshalByRefObject, IDataReader, IDisposable, IDataRecord, IEnumerable
  37 #endif
  38         {
  39                 #region Fields
  40
  41                 OracleCommand command;
  42                 ArrayList dataTypeNames;
  43 #if !NET_2_0
  44                 bool disposed;
  45 #endif
  46                 bool isClosed;
  47                 bool hasRows;
  48                 DataTable schemaTable;
  49                 CommandBehavior behavior;
  50
  51                 int recordsAffected = -1;
  52                 OciStatementType statementType;
  53                 OciStatementHandle statement;
  54
  55                 #endregion // Fields
  56
  57                 #region Constructors
  58
  59                 internal OracleDataReader (OracleCommand command, OciStatementHandle statement, bool extHasRows, CommandBehavior behavior)
  60                 {
  61                         this.command = command;
  62                         this.hasRows = extHasRows;
  63                         this.schemaTable = ConstructSchemaTable ();
  64                         this.statement = statement;
  65                         this.statementType = statement.GetStatementType ();
  66                         this.behavior = behavior;
  67                 }
  68
  69                 ~OracleDataReader ()
  70                 {
  71                         Dispose (false);
  72                 }
  73
  74                 #endregion // Constructors
  75
  76                 #region Properties
  77
  78                 public
  79 #if NET_2_0
  80                 override
  81 #endif
  82                 int Depth {
  83                         get { return 0; }
  84                 }
  85
  86                 public
  87 #if NET_2_0
  88                 override
  89 #endif
  90                 int FieldCount {
  91                         get { return statement.ColumnCount; }
  92                 }
  93
  94                 public
  95 #if NET_2_0
  96                 override
  97 #endif
  98                 bool HasRows {
  99                         get { return hasRows; }
 100                 }
 101
 102                 public
 103 #if NET_2_0
 104                 override
 105 #endif
 106                 bool IsClosed {
 107                         get { return isClosed; }
 108                 }
 109
 110                 public
 111 #if NET_2_0
 112                 override
 113 #endif
 114                 object this [string name] {
 115                         get { return GetValue (GetOrdinal (name)); }
 116                 }
 117
 118                 public
 119 #if NET_2_0
 120                 override
 121 #endif
 122                 object this [int i] {
 123                         get { return GetValue (i); }
 124                 }
 125
 126                 public
 127 #if NET_2_0
 128                 override
 129 #endif
 130                 int RecordsAffected {
 131                         get {
 132                                 return GetRecordsAffected ();
 133                         }
 134                 }
 135
 136                 #endregion // Properties
 137
 138                 #region Methods
 139
 140                 public
 141 #if NET_2_0
 142                 override
 143 #endif
 144                 void Close ()
 145                 {
 146                         if (!isClosed) {
 147                                 GetRecordsAffected ();
 148                                 if (command != null)
 149                                         command.CloseDataReader ();
 150                         }
 151                         if (statement != null) {
 152                                 statement.Dispose();
 153                                 statement = null;
 154                         }
 155 #if NET_2_0
 156                         if (schemaTable != null) {
 157                                 schemaTable.Dispose ();
 158                                 schemaTable = null;
 159                         }
 160 #endif
 161                         isClosed = true;
 162                 }
 163
 164                 private static DataTable ConstructSchemaTable ()
 165                 {
 166                         Type booleanType = typeof (bool);
 167                         Type stringType = typeof (string);
 168                         Type intType = typeof (int);
 169                         Type typeType = typeof (Type);
 170                         Type shortType = typeof (short);
 171
 172                         DataTable schemaTable = new DataTable ("SchemaTable");
 173                         schemaTable.Columns.Add ("ColumnName", stringType);
 174                         schemaTable.Columns.Add ("ColumnOrdinal", intType);
 175                         schemaTable.Columns.Add ("ColumnSize", intType);
 176                         schemaTable.Columns.Add ("NumericPrecision", shortType);
 177                         schemaTable.Columns.Add ("NumericScale", shortType);
 178                         schemaTable.Columns.Add ("DataType", typeType);
 179                         schemaTable.Columns.Add ("ProviderType", intType);
 180                         schemaTable.Columns.Add ("IsLong", booleanType);
 181                         schemaTable.Columns.Add ("AllowDBNull", booleanType);
 182                         schemaTable.Columns.Add ("IsAliased", booleanType);
 183                         schemaTable.Columns.Add ("IsExpression", booleanType);
 184                         schemaTable.Columns.Add ("IsKey", booleanType);
 185                         schemaTable.Columns.Add ("IsUnique", booleanType);
 186                         schemaTable.Columns.Add ("BaseSchemaName", stringType);
 187                         schemaTable.Columns.Add ("BaseTableName", stringType);
 188                         schemaTable.Columns.Add ("BaseColumnName", stringType);
 189
 190                         return schemaTable;
 191                 }
 192
 193 #if !NET_2_0
 194                 private void Dispose (bool disposing)
 195                 {
 196                         if (!disposed) {
 197                                 if (disposing)
 198                                         Close ();
 199                                 disposed = true;
 200                         }
 201                 }
 202
 203                 public void Dispose ()
 204                 {
 205                         Dispose (true);
 206                         GC.SuppressFinalize (this);
 207                 }
 208 #endif
 209
 210                 public
 211 #if NET_2_0
 212                 override
 213 #endif
 214                 bool GetBoolean (int i)
 215                 {
 216                         throw new NotSupportedException ();
 217                 }
 218
 219                 public
 220 #if NET_2_0
 221                 override
 222 #endif
 223                 byte GetByte (int i)
 224                 {
 225                         throw new NotSupportedException ();
 226                 }
 227
 228                 public
 229 #if NET_2_0
 230                 override
 231 #endif
 232                 long GetBytes (int i, long fieldOffset, byte[] buffer2, int bufferoffset, int length)
 233                 {
 234                         byte[] value = (byte[]) GetValue (i);
 235
 236                         if (buffer2 == null)
 237                                 return value.Length; // Return length of data
 238
 239                         // Copy data into buffer
 240                         long lobLength = value.Length;
 241                         if ((lobLength - fieldOffset) < length)
 242                                 length = (int) (lobLength - fieldOffset);
 243                         Array.Copy (value, (int) fieldOffset, buffer2,
 244                                 bufferoffset, length);
 245                         return length; // return actual read count
 246                 }
 247
 248                 public
 249 #if NET_2_0
 250                 override
 251 #endif
 252                 char GetChar (int i)
 253                 {
 254                         throw new NotSupportedException ();
 255                 }
 256
 257                 public
 258 #if NET_2_0
 259                 override
 260 #endif
 261                 long GetChars (int i, long fieldOffset, char[] buffer2, int bufferoffset, int length)
 262                 {
 263                         char [] value = (char[]) GetValue (i);
 264                         Array.Copy (value, (int) fieldOffset, buffer2,
 265                                 bufferoffset, length);
 266                         return (value.Length - fieldOffset);
 267                 }
 268
 269 #if !NET_2_0
 270                 [MonoTODO]
 271                 public IDataReader GetData (int i)
 272                 {
 273                         throw new NotImplementedException ();
 274                 }
 275 #endif
 276
 277                 public
 278 #if NET_2_0
 279                 override
 280 #endif
 281                 string GetDataTypeName (int i)
 282                 {
 283                         return dataTypeNames [i].ToString ().ToUpper ();
 284                 }
 285
 286                 public
 287 #if NET_2_0
 288                 override
 289 #endif
 290                 DateTime GetDateTime (int i)
 291                 {
 292                         IConvertible c = (IConvertible) GetValue (i);
 293                         return c.ToDateTime (CultureInfo.CurrentCulture);
 294                 }
 295
 296                 public
 297 #if NET_2_0
 298                 override
 299 #endif
 300                 decimal GetDecimal (int i)
 301                 {
 302                         IConvertible c = (IConvertible) GetValue (i);
 303                         return c.ToDecimal (CultureInfo.CurrentCulture);
 304                 }
 305
 306                 public
 307 #if NET_2_0
 308                 override
 309 #endif
 310                 double GetDouble (int i)
 311                 {
 312                         IConvertible c = (IConvertible) GetValue (i);
 313                         return c.ToDouble (CultureInfo.CurrentCulture);
 314                 }
 315
 316                 public
 317 #if NET_2_0
 318                 override
 319 #endif
 320                 Type GetFieldType (int i)
 321                 {
 322                         OciDefineHandle defineHandle = (OciDefineHandle) statement.Values [i];
 323                         return defineHandle.FieldType;
 324                 }
 325
 326                 public
 327 #if NET_2_0
 328                 override
 329 #endif
 330                 float GetFloat (int i)
 331                 {
 332                         IConvertible c = (IConvertible) GetValue (i);
 333                         return c.ToSingle (CultureInfo.CurrentCulture);
 334                 }
 335
 336                 public
 337 #if NET_2_0
 338                 override
 339 #endif
 340                 Guid GetGuid (int i)
 341                 {
 342                         throw new NotSupportedException ();
 343                 }
 344
 345                 public
 346 #if NET_2_0
 347                 override
 348 #endif
 349                 short GetInt16 (int i)
 350                 {
 351                         throw new NotSupportedException ();
 352                 }
 353
 354                 public
 355 #if NET_2_0
 356                 override
 357 #endif
 358                 int GetInt32 (int i)
 359                 {
 360                         IConvertible c = (IConvertible) GetValue (i);
 361                         return c.ToInt32 (CultureInfo.CurrentCulture);
 362                 }
 363
 364                 public
 365 #if NET_2_0
 366                 override
 367 #endif
 368                 long GetInt64 (int i)
 369                 {
 370                         IConvertible c = (IConvertible) GetValue (i);
 371                         return c.ToInt64 (CultureInfo.CurrentCulture);
 372                 }
 373
 374                 public
 375 #if NET_2_0
 376                 override
 377 #endif
 378                 string GetName (int i)
 379                 {
 380                         return statement.GetParameter (i).GetName ();
 381                 }
 382
 383                 [MonoTODO]
 384                 public OracleBFile GetOracleBFile (int i)
 385                 {
 386                         throw new NotImplementedException ();
 387                 }
 388
 389                 [MonoTODO]
 390                 public OracleBinary GetOracleBinary (int i)
 391                 {
 392                         if (IsDBNull (i))
 393                                 throw new InvalidOperationException("The value is null");
 394
 395                         return new OracleBinary ((byte[]) GetValue (i));
 396                 }
 397
 398                 public OracleLob GetOracleLob (int i)
 399                 {
 400                         if (IsDBNull (i))
 401                                 throw new InvalidOperationException("The value is null");
 402
 403                         OracleLob output = (OracleLob) ((OciDefineHandle) statement.Values [i]).GetValue (
 404                                 command.Connection.SessionFormatProvider, command.Connection);
 405                         output.connection = command.Connection;
 406                         return output;
 407                 }
 408
 409                 public OracleNumber GetOracleNumber (int i)
 410                 {
 411                         if (IsDBNull (i))
 412                                 throw new InvalidOperationException("The value is null");
 413
 414                         return new OracleNumber (GetDecimal (i));
 415                 }
 416
 417                 public OracleDateTime GetOracleDateTime (int i)
 418                 {
 419                         if (IsDBNull (i))
 420                                 throw new InvalidOperationException("The value is null");
 421
 422                         return new OracleDateTime (GetDateTime (i));
 423                 }
 424
 425                 public OracleMonthSpan GetOracleMonthSpan (int i)
 426                 {
 427                         if (IsDBNull (i))
 428                                 throw new InvalidOperationException("The value is null");
 429
 430                         OracleMonthSpan output = (OracleMonthSpan) ((OciDefineHandle) statement.Values [i]).GetValue (
 431                                 command.Connection.SessionFormatProvider, command.Connection);
 432                         return output;
 433                 }
 434
 435                 public OracleString GetOracleString (int i)
 436                 {
 437                         if (IsDBNull (i))
 438                                 throw new InvalidOperationException("The value is null");
 439
 440                         return new OracleString (GetString (i));
 441                 }
 442
 443                 public object GetOracleValue (int i)
 444                 {
 445                         OciDefineHandle defineHandle = (OciDefineHandle) statement.Values [i];
 446
 447                         switch (defineHandle.DataType) {
 448                         case OciDataType.Raw:
 449                                 return GetOracleBinary (i);
 450                         case OciDataType.Date:
 451                                 return GetOracleDateTime (i);
 452                         case OciDataType.Clob:
 453                         case OciDataType.Blob:
 454                                 return GetOracleLob (i);
 455                         case OciDataType.Integer:
 456                         case OciDataType.Number:
 457                         case OciDataType.Float:
 458                                 return GetOracleNumber (i);
 459                         case OciDataType.VarChar2:
 460                         case OciDataType.String:
 461                         case OciDataType.VarChar:
 462                         case OciDataType.Char:
 463                         case OciDataType.CharZ:
 464                         case OciDataType.OciString:
 465                         case OciDataType.LongVarChar:
 466                         case OciDataType.Long:
 467                         case OciDataType.RowIdDescriptor:
 468                                 return GetOracleString (i);
 469                         case OciDataType.IntervalDayToSecond:
 470                                 return GetOracleTimeSpan (i);
 471                         case OciDataType.IntervalYearToMonth:
 472                                 return GetOracleMonthSpan (i);
 473                         default:
 474                                 throw new NotImplementedException ();
 475                         }
 476                 }
 477
 478                 public int GetOracleValues (object[] values)
 479                 {
 480                         int len = values.Length;
 481                         int count = statement.ColumnCount;
 482                         int retval = 0;
 483
 484                         if (len > count)
 485                                 retval = count;
 486                         else
 487                                 retval = len;
 488
 489                         for (int i = 0; i < retval; i += 1)
 490                                 values [i] = GetOracleValue (i);
 491
 492                         return retval;
 493                 }
 494
 495                 public OracleTimeSpan GetOracleTimeSpan (int i)
 496                 {
 497                         return new OracleTimeSpan (GetTimeSpan (i));
 498                 }
 499
 500                 public
 501 #if NET_2_0
 502                 override
 503 #endif
 504                 int GetOrdinal (string name)
 505                 {
 506                         int i = GetOrdinalInternal (name);
 507                         if (i == -1)
 508                                 throw new IndexOutOfRangeException ();
 509                         return i;
 510                 }
 511
 512                 private int GetOrdinalInternal (string name)
 513                 {
 514                         int i;
 515
 516                         for (i = 0; i < statement.ColumnCount; i += 1) {
 517                                 if (String.Compare (statement.GetParameter(i).GetName(), name, false) == 0)
 518                                         return i;
 519                         }
 520
 521                         for (i = 0; i < statement.ColumnCount; i += 1) {
 522                                 if (String.Compare (statement.GetParameter(i).GetName(), name, true) == 0)
 523                                         return i;
 524                         }
 525
 526                         return -1;
 527                 }
 528
 529                 private int GetRecordsAffected ()
 530                 {
 531                         if (statementType == OciStatementType.Select)
 532                                 return -1;
 533                         else {
 534                                 if (!isClosed) {
 535                                         if (recordsAffected == -1)
 536                                                 if (statement != null)
 537                                                         recordsAffected = statement.GetAttributeInt32 (OciAttributeType.RowCount, command.ErrorHandle);
 538                                 }
 539                         }
 540
 541                         return recordsAffected;
 542                 }
 543
 544                 // get the KeyInfo about table columns (primary key)
 545                 private StringCollection GetKeyInfo (out string ownerName, out string tableName)
 546                 {
 547                         ArrayList tables = new ArrayList ();
 548                         ParseSql (command.CommandText, ref tables);
 549                         // TODO: handle multiple tables
 550                         GetOwnerAndName ((string)tables[0], out ownerName, out tableName);
 551                         return GetKeyColumns (ownerName, tableName);
 552                 }
 553
 554                 // get the columns in a table that have a primary key
 555                 private StringCollection GetKeyColumns(string owner, string table)
 556                 {
 557                         OracleCommand cmd = command.Connection.CreateCommand ();
 558
 559                         StringCollection columns = new StringCollection ();
 560
 561                         if (command.Transaction != null)
 562                                 cmd.Transaction = command.Transaction;
 563
 564                         cmd.CommandText = "select col.column_name " +
 565                                 "from all_constraints pk, all_cons_columns col " +
 566                                 "where pk.owner = '" + owner + "' " +
 567                                 "and pk.table_name = '" + table + "' " +
 568                                 "and pk.constraint_type = 'P' " +
 569                                 "and pk.owner = col.owner " +
 570                                 "and pk.table_name = col.table_name " +
 571                                 "and pk.constraint_name = col.constraint_name";
 572
 573                         OracleDataReader rdr = cmd.ExecuteReader ();
 574                         while (rdr.Read ())
 575                                 columns.Add (rdr.GetString (0));
 576
 577                         rdr.Close();
 578                         rdr = null;
 579                         cmd.Dispose();
 580                         cmd = null;
 581
 582                         return columns;
 583                 }
 584
 585                 // parse the list of table names in the SQL
 586                 // TODO: parse the column aliases and table aliases too
 587                 //       and determine if a column is a true table column
 588                 //       or an expression
 589                 private void ParseSql (string sql, ref ArrayList tables) {
 590                         if (sql == String.Empty)
 591                                 return;
 592
 593                         char[] chars = sql.ToCharArray ();
 594                         StringBuilder wb = new StringBuilder ();
 595
 596                         bool bFromFound = false;
 597                         bool bEnd = false;
 598                         int i = 0;
 599                         bool bTableFound = false;
 600
 601                         for (; !bEnd && i < chars.Length; i++) {
 602                                 char ch = chars[i];
 603
 604                                 if (Char.IsLetter (ch)) {
 605                                         wb.Append (ch);
 606                                 } else if (Char.IsWhiteSpace (ch)) {
 607                                         if (wb.Length > 0) {
 608                                                 if (!bFromFound) {
 609                                                         string word = wb.ToString ().ToUpper ();
 610                                                         if (word.Equals ("FROM")) {
 611                                                                 bFromFound = true;
 612                                                         }
 613                                                         wb = null;
 614                                                         wb = new StringBuilder ();
 615                                                         bTableFound = false;
 616                                                 } else {
 617                                                         switch (wb.ToString ().ToUpper ()) {
 618                                                         case "WHERE":
 619                                                         case "ORDER":
 620                                                         case "GROUP":
 621                                                                 bEnd = true;
 622                                                                 bTableFound = false;
 623                                                                 break;
 624                                                         default:
 625                                                                 if (bTableFound)
 626                                                                         bTableFound = false; // this is done in case of a table alias
 627                                                                 else {
 628                                                                         bTableFound = true;
 629                                                                         tables.Add (wb.ToString ().ToUpper ());
 630                                                                 }
 631                                                                 wb = null;
 632                                                                 wb = new StringBuilder ();
 633                                                                 break;
 634                                                         }
 635                                                 }
 636                                         }
 637                                 } else if (bFromFound) {
 638                                         switch (ch) {
 639                                         case ',':
 640                                                 if (bTableFound)
 641                                                         bTableFound = false;
 642                                                 else
 643                                                         tables.Add (wb.ToString ().ToUpper ());
 644                                                 wb = null;
 645                                                 wb = new StringBuilder ();
 646                                                 break;
 647                                         case '$':
 648                                         case '_':
 649                                         case '.':
 650                                                 wb.Append (ch);
 651                                                 break;
 652                                         }
 653                                 }
 654                         }
 655                         if (!bEnd) {
 656                                 if (wb.Length > 0) {
 657                                         if (!bFromFound && wb.ToString ().ToUpper ().Equals ("FROM"))
 658                                                 bFromFound = true;
 659                                         if (bFromFound) {
 660                                                 switch(wb.ToString ().ToUpper ()) {
 661                                                 case "WHERE":
 662                                                 case "ORDER":
 663                                                 case "GROUP":
 664                                                         bEnd = true;
 665                                                         break;
 666                                                 default:
 667                                                         if (!bTableFound)
 668                                                                 tables.Add (wb.ToString ().ToUpper ());
 669                                                         break;
 670                                                 }
 671                                         }
 672                                 }
 673                         }
 674                 }
 675
 676                 // takes a object name like "owner.name" and parses it into "owner" and "name" strings
 677                 // if object name is only "name", then it gets the username as the owner and returns
 678                 // the name
 679                 private void GetOwnerAndName (string objectName, out string owner, out string name)
 680                 {
 681                         int idx = objectName.IndexOf (".");
 682                         if (idx == -1) {
 683                                 OracleCommand cmd = command.Connection.CreateCommand ();
 684                                 if (command.Transaction != null)
 685                                         cmd.Transaction = command.Transaction;
 686
 687                                 cmd.CommandText = "SELECT USER FROM DUAL";
 688                                 owner = (string) cmd.ExecuteScalar();
 689                                 name = objectName;
 690                                 cmd.Dispose();
 691                                 cmd = null;
 692                         } else {
 693                                 owner = objectName.Substring (0, idx);
 694                                 name = objectName.Substring (idx + 1);
 695                         }
 696                 }
 697
 698                 [MonoTODO("Implement this properly, with all needed information.")]
 699                 public
 700 #if NET_2_0
 701                 override
 702 #endif
 703                 DataTable GetSchemaTable ()
 704                 {
 705                         StringCollection keyinfo = null;
 706
 707                         if (schemaTable.Rows != null && schemaTable.Rows.Count > 0)
 708                                 return schemaTable;
 709
 710                         string owner = String.Empty;
 711                         string table = String.Empty;
 712                         if ((behavior & CommandBehavior.KeyInfo) != 0)
 713                                 keyinfo = GetKeyInfo (out owner, out table);
 714
 715                         dataTypeNames = new ArrayList ();
 716
 717                         for (int i = 0; i < statement.ColumnCount; i += 1) {
 718                                 DataRow row = schemaTable.NewRow ();
 719
 720                                 OciParameterDescriptor parameter = statement.GetParameter (i);
 721
 722                                 dataTypeNames.Add (parameter.GetDataTypeName ());
 723
 724                                 row ["ColumnName"]              = parameter.GetName ();
 725                                 row ["ColumnOrdinal"]           = i + 1;
 726                                 row ["ColumnSize"]              = parameter.GetDataSize ();
 727                                 row ["NumericPrecision"]        = parameter.GetPrecision ();
 728                                 row ["NumericScale"]            = parameter.GetScale ();
 729
 730                                 string sDataTypeName            = parameter.GetDataTypeName ();
 731                                 row ["DataType"]                = parameter.GetFieldType (sDataTypeName);
 732
 733                                 OciDataType ociType = parameter.GetDataType();
 734                                 OracleType oraType = OciParameterDescriptor.OciDataTypeToOracleType (ociType);
 735                                 row ["ProviderType"]            = (int) oraType;
 736
 737                                 if (ociType == OciDataType.Blob || ociType == OciDataType.Clob)
 738                                         row ["IsLong"]          = true;
 739                                 else
 740                                         row ["IsLong"]          = false;
 741
 742                                 row ["AllowDBNull"]             = parameter.GetIsNull ();
 743
 744                                 row ["IsAliased"]               = DBNull.Value; // TODO:
 745                                 row ["IsExpression"]            = DBNull.Value; // TODO:
 746
 747                                 if ((behavior & CommandBehavior.KeyInfo) != 0) {
 748                                         if (keyinfo.IndexOf ((string)row ["ColumnName"]) >= 0)
 749                                                 row ["IsKey"] = true;
 750                                         else
 751                                                 row ["IsKey"] = false;
 752
 753                                         row ["IsUnique"]        = DBNull.Value; // TODO: only set this if CommandBehavior.KeyInfo, otherwise, null
 754                                         row ["BaseSchemaName"]  = owner;
 755                                         row ["BaseTableName"]   = table;
 756                                         row ["BaseColumnName"]  = row ["ColumnName"];
 757                                 } else {
 758                                         row ["IsKey"]           = DBNull.Value;
 759                                         row ["IsUnique"]        = DBNull.Value;
 760                                         row ["BaseSchemaName"]  = DBNull.Value;
 761                                         row ["BaseTableName"]   = DBNull.Value;
 762                                         row ["BaseColumnName"]  = DBNull.Value;
 763                                 }
 764
 765                                 schemaTable.Rows.Add (row);
 766                         }
 767
 768                         return schemaTable;
 769                 }
 770
 771                 public
 772 #if NET_2_0
 773                 override
 774 #endif
 775                 string GetString (int i)
 776                 {
 777                         return (string) GetValue (i);
 778                 }
 779
 780                 public TimeSpan GetTimeSpan (int i)
 781                 {
 782                         return (TimeSpan) GetValue (i);
 783                 }
 784
 785                 public
 786 #if NET_2_0
 787                 override
 788 #endif
 789                 object GetValue (int i)
 790                 {
 791                         OciDefineHandle defineHandle = (OciDefineHandle) statement.Values [i];
 792
 793                         if (defineHandle.IsNull)
 794                                 return DBNull.Value;
 795
 796                         switch (defineHandle.DataType) {
 797                         case OciDataType.Blob:
 798                         case OciDataType.Clob:
 799                                 OracleLob lob = GetOracleLob (i);
 800                                 object value = lob.Value;
 801                                 lob.Close ();
 802                                 return value;
 803                         default:
 804                                 return defineHandle.GetValue (command.Connection.SessionFormatProvider, command.Connection);
 805                         }
 806                 }
 807
 808                 public
 809 #if NET_2_0
 810                 override
 811 #endif
 812                 int GetValues (object [] values)
 813                 {
 814                         int len = values.Length;
 815                         int count = statement.ColumnCount;
 816                         int retval = 0;
 817
 818                         if (len > count)
 819                                 retval = count;
 820                         else
 821                                 retval = len;
 822
 823                         for (int i = 0; i < retval; i += 1)
 824                                 values [i] = GetValue (i);
 825
 826                         return retval;
 827                 }
 828
 829 #if NET_2_0
 830                 public override IEnumerator GetEnumerator ()
 831 #else
 832                 IEnumerator IEnumerable.GetEnumerator ()
 833 #endif
 834                 {
 835                         return new DbEnumerator (this);
 836                 }
 837
 838                 public
 839 #if NET_2_0
 840                 override
 841 #endif
 842                 bool IsDBNull (int i)
 843                 {
 844                         OciDefineHandle defineHandle = (OciDefineHandle) statement.Values [i];
 845                         return defineHandle.IsNull;
 846                 }
 847
 848                 void ValidateState ()
 849                 {
 850                         if (IsClosed)
 851                                 throw new InvalidOperationException ("Invalid attempt to read data when reader is closed");
 852                 }
 853
 854                 public
 855 #if NET_2_0
 856                 override
 857 #endif
 858                 bool NextResult ()
 859                 {
 860                         ValidateState ();
 861
 862                         if (statement == null)
 863                                 return false;
 864
 865                         statement.Dispose ();
 866                         statement = null;
 867
 868                         statement = command.GetNextResult ();
 869
 870                         if (statement == null)
 871                                 return false;
 872
 873                         return true;
 874                 }
 875
 876                 public
 877 #if NET_2_0
 878                 override
 879 #endif
 880                 bool Read ()
 881                 {
 882                         ValidateState ();
 883
 884                         if (hasRows) {
 885                                 bool retval = statement.Fetch ();
 886                                 hasRows = retval;
 887                                 return retval;
 888                         }
 889                         return false;
 890                 }
 891
 892 #if NET_2_0
 893                 [MonoTODO]
 894                 public override Type GetProviderSpecificFieldType (int i)
 895                 {
 896                         return GetOracleValue (i).GetType ();
 897                 }
 898
 899                 [MonoTODO]
 900                 public override object GetProviderSpecificValue (int i)
 901                 {
 902                         return GetOracleValue (i);
 903                 }
 904
 905                 [MonoTODO]
 906                 public override int GetProviderSpecificValues (object [] values)
 907                 {
 908                         return GetOracleValues (values);
 909                 }
 910 #endif
 911
 912                 #endregion // Methods
 913         }
 914 }