mcs/class/System.Data/System.Data.OleDb/OleDbDataReader.cs

   1 //
   2 // System.Data.OleDb.OleDbDataReader
   3 //
   4 // Author:
   5 //   Rodrigo Moya (rodrigo@ximian.com)
   6 //   Tim Coleman (tim@timcoleman.com)
   7 //
   8 // Copyright (C) Rodrigo Moya, 2002
   9 // Copyright (C) Tim Coleman, 2002
  10 // Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
  11 //
  12 // Permission is hereby granted, free of charge, to any person obtaining
  13 // a copy of this software and associated documentation files (the
  14 // "Software"), to deal in the Software without restriction, including
  15 // without limitation the rights to use, copy, modify, merge, publish,
  16 // distribute, sublicense, and/or sell copies of the Software, and to
  17 // permit persons to whom the Software is furnished to do so, subject to
  18 // the following conditions:
  19 //
  20 // The above copyright notice and this permission notice shall be
  21 // included in all copies or substantial portions of the Software.
  22 //
  23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  30 //
  31
  32 using System.Collections;
  33 using System.ComponentModel;
  34 using System.Data.Common;
  35 using System.Runtime.InteropServices;
  36
  37 namespace System.Data.OleDb
  38 {
  39         public sealed class OleDbDataReader : DbDataReader, IDisposable
  40         {
  41                 #region Fields
  42
  43                 private OleDbCommand command;
  44                 private bool open;
  45                 private ArrayList gdaResults;
  46                 private int currentResult;
  47                 private int currentRow;
  48                 private bool disposed;
  49
  50                 #endregion
  51
  52                 #region Constructors
  53
  54                 internal OleDbDataReader (OleDbCommand command, ArrayList results)
  55                 {
  56                         this.command = command;
  57                         open = true;
  58                         if (results != null)
  59                                 gdaResults = results;
  60                         else
  61                                 gdaResults = new ArrayList ();
  62                         currentResult = -1;
  63                         currentRow = -1;
  64                 }
  65
  66                 #endregion
  67
  68                 #region Properties
  69
  70                 public
  71                 override
  72                 int Depth {
  73                         get {
  74                                 return 0; // no nested selects supported
  75                         }
  76                 }
  77
  78                 public
  79                 override
  80                 int FieldCount {
  81                         get {
  82                                 if (currentResult < 0 || currentResult >= gdaResults.Count)
  83                                         return 0;
  84
  85                                 return libgda.gda_data_model_get_n_columns (
  86                                         (IntPtr) gdaResults[currentResult]);
  87                         }
  88                 }
  89
  90                 public
  91                 override
  92                 bool IsClosed {
  93                         get {
  94                                 return !open;
  95                         }
  96                 }
  97
  98                 public
  99                 override
 100                 object this[string name] {
 101                         get {
 102                                 int pos;
 103
 104                                 if (currentResult == -1)
 105                                         throw new InvalidOperationException ();
 106
 107                                 pos = libgda.gda_data_model_get_column_position (
 108                                         (IntPtr) gdaResults[currentResult],
 109                                         name);
 110                                 if (pos == -1)
 111                                         throw new IndexOutOfRangeException ();
 112
 113                                 return this[pos];
 114                         }
 115                 }
 116
 117                 public
 118                 override
 119                 object this[int index] {
 120                         get {
 121                                 return (object) GetValue (index);
 122                         }
 123                 }
 124
 125                 public
 126                 override
 127                 int RecordsAffected {
 128                         get {
 129                                 int total_rows;
 130
 131                                 if (currentResult < 0 || currentResult >= gdaResults.Count)
 132                                         return 0;
 133
 134                                 total_rows = libgda.gda_data_model_get_n_rows (
 135                                         (IntPtr) gdaResults[currentResult]);
 136                                 if (total_rows > 0) {
 137                                         if (FieldCount > 0) {
 138                                                 // It's a SELECT statement
 139                                                 return -1;
 140                                         }
 141                                 }
 142
 143                                 return FieldCount > 0 ? -1 : total_rows;
 144                         }
 145                 }
 146
 147                 [MonoTODO]
 148                 public
 149                 override
 150                 bool HasRows {
 151                         get {
 152                                 throw new NotImplementedException ();
 153                         }
 154                 }
 155
 156                 [MonoTODO]
 157                 public override int VisibleFieldCount {
 158                         get {
 159                                 throw new NotImplementedException ();
 160                         }
 161                 }
 162
 163                 #endregion
 164
 165                 #region Methods
 166
 167                 public
 168                 override
 169                 void Close ()
 170                 {
 171                         for (int i = 0; i < gdaResults.Count; i++) {
 172                                 IntPtr obj = (IntPtr) gdaResults[i];
 173                                 libgda.FreeObject (obj);
 174                         }
 175
 176                         gdaResults.Clear ();
 177                         gdaResults = null;
 178
 179                         open = false;
 180                         currentResult = -1;
 181                         currentRow = -1;
 182                 }
 183
 184                 public
 185                 override
 186                 bool GetBoolean (int ordinal)
 187                 {
 188                         IntPtr value;
 189
 190                         if (currentResult == -1)
 191                                 throw new InvalidCastException ();
 192
 193                         value = libgda.gda_data_model_get_value_at ((IntPtr) gdaResults[currentResult],
 194                                                                     ordinal, currentRow);
 195                         if (value == IntPtr.Zero)
 196                                 throw new InvalidCastException ();
 197
 198                         if (libgda.gda_value_get_type (value) != GdaValueType.Boolean)
 199                                 throw new InvalidCastException ();
 200                         return libgda.gda_value_get_boolean (value);
 201                 }
 202
 203                 public
 204                 override
 205                 byte GetByte (int ordinal)
 206                 {
 207                         IntPtr value;
 208
 209                         if (currentResult == -1)
 210                                 throw new InvalidCastException ();
 211
 212                         value = libgda.gda_data_model_get_value_at ((IntPtr) gdaResults[currentResult],
 213                                                                     ordinal, currentRow);
 214                         if (value == IntPtr.Zero)
 215                                 throw new InvalidCastException ();
 216
 217                         if (libgda.gda_value_get_type (value) != GdaValueType.Tinyint)
 218                                 throw new InvalidCastException ();
 219                         return libgda.gda_value_get_tinyint (value);
 220                 }
 221
 222                 [MonoTODO]
 223                 public
 224                 override
 225                 long GetBytes (int ordinal, long dataIndex, byte[] buffer, int bufferIndex, int length)
 226                 {
 227                         throw new NotImplementedException ();
 228                 }
 229
 230                 [EditorBrowsableAttribute (EditorBrowsableState.Never)]
 231                 public
 232                 override
 233                 char GetChar (int ordinal)
 234                 {
 235                         IntPtr value;
 236
 237                         if (currentResult == -1)
 238                                 throw new InvalidCastException ();
 239
 240                         value = libgda.gda_data_model_get_value_at ((IntPtr) gdaResults[currentResult],
 241                                 ordinal, currentRow);
 242                         if (value == IntPtr.Zero)
 243                                 throw new InvalidCastException ();
 244
 245                         if (libgda.gda_value_get_type (value) != GdaValueType.Tinyint)
 246                                 throw new InvalidCastException ();
 247                         return (char) libgda.gda_value_get_tinyint (value);
 248                 }
 249
 250                 [MonoTODO]
 251                 public
 252                 override
 253                 long GetChars (int ordinal, long dataIndex, char[] buffer, int bufferIndex, int length)
 254                 {
 255                         throw new NotImplementedException ();
 256                 }
 257
 258                 [MonoTODO]
 259                 [EditorBrowsable (EditorBrowsableState.Advanced)]
 260                 public new OleDbDataReader GetData (int ordinal)
 261                 {
 262                         throw new NotImplementedException ();
 263                 }
 264
 265                 protected override DbDataReader GetDbDataReader (int ordinal)
 266                 {
 267                         return this.GetData (ordinal);
 268                 }
 269
 270                 public
 271                 override
 272                 string GetDataTypeName (int index)
 273                 {
 274                         IntPtr attrs;
 275                         GdaValueType type;
 276
 277                         if (currentResult == -1)
 278                                 return "unknown";
 279
 280
 281                         attrs = libgda.gda_data_model_describe_column ((IntPtr) gdaResults[currentResult],
 282                                 index);
 283                         if (attrs == IntPtr.Zero)
 284                                 return "unknown";
 285
 286                         type = libgda.gda_field_attributes_get_gdatype (attrs);
 287                         libgda.gda_field_attributes_free (attrs);
 288
 289                         return libgda.gda_type_to_string (type);
 290                 }
 291
 292                 public
 293                 override
 294                 DateTime GetDateTime (int ordinal)
 295                 {
 296                         IntPtr value;
 297
 298                         if (currentResult == -1)
 299                                 throw new InvalidCastException ();
 300
 301                         value = libgda.gda_data_model_get_value_at ((IntPtr) gdaResults[currentResult],
 302                                 ordinal, currentRow);
 303                         if (value == IntPtr.Zero)
 304                                 throw new InvalidCastException ();
 305
 306                         if (libgda.gda_value_get_type (value) == GdaValueType.Date) {
 307                                 GdaDate gdt;
 308
 309                                 gdt = (GdaDate) Marshal.PtrToStructure (libgda.gda_value_get_date (value),
 310                                                                         typeof (GdaDate));
 311                                 return new DateTime ((int) gdt.year, (int) gdt.month, (int) gdt.day);
 312                         } else if (libgda.gda_value_get_type (value) == GdaValueType.Time) {
 313                                 GdaTime gdt;
 314
 315                                 gdt = (GdaTime) Marshal.PtrToStructure (libgda.gda_value_get_time (value),
 316                                                                         typeof (GdaTime));
 317                                 return new DateTime (0, 0, 0, (int) gdt.hour, (int) gdt.minute, (int) gdt.second, 0);
 318                         } else if (libgda.gda_value_get_type (value) == GdaValueType.Timestamp) {
 319                                 GdaTimestamp gdt;
 320
 321                                 gdt = (GdaTimestamp) Marshal.PtrToStructure (libgda.gda_value_get_timestamp (value),
 322                                         typeof (GdaTimestamp));
 323
 324                                 return new DateTime ((int) gdt.year, (int) gdt.month, (int) gdt.day,
 325                                         (int) gdt.hour, (int) gdt.minute, (int) gdt.second,
 326                                         (int) gdt.fraction);
 327                         }
 328
 329                         throw new InvalidCastException ();
 330                 }
 331
 332                 [MonoTODO]
 333                 public
 334                 override
 335                 decimal GetDecimal (int ordinal)
 336                 {
 337                         throw new NotImplementedException ();
 338                 }
 339
 340                 public
 341                 override
 342                 double GetDouble (int ordinal)
 343                 {
 344                         IntPtr value;
 345
 346                         if (currentResult == -1)
 347                                 throw new InvalidCastException ();
 348
 349                         value = libgda.gda_data_model_get_value_at ((IntPtr) gdaResults[currentResult],
 350                                                                     ordinal, currentRow);
 351                         if (value == IntPtr.Zero)
 352                                 throw new InvalidCastException ();
 353
 354                         if (libgda.gda_value_get_type (value) != GdaValueType.Double)
 355                                 throw new InvalidCastException ();
 356                         return libgda.gda_value_get_double (value);
 357                 }
 358
 359                 public
 360                 override
 361                 Type GetFieldType (int index)
 362                 {
 363                         IntPtr value;
 364                         GdaValueType type;
 365
 366                         if (currentResult == -1)
 367                                 throw new IndexOutOfRangeException ();
 368
 369                         value = libgda.gda_data_model_get_value_at ((IntPtr) gdaResults[currentResult],
 370                                 index, currentRow);
 371                         if (value == IntPtr.Zero)
 372                                 throw new IndexOutOfRangeException ();
 373
 374                         type = libgda.gda_value_get_type (value);
 375                         switch (type) {
 376                         case GdaValueType.Bigint : return typeof (long);
 377                         case GdaValueType.Boolean : return typeof (bool);
 378                         case GdaValueType.Date : return typeof (DateTime);
 379                         case GdaValueType.Double : return typeof (double);
 380                         case GdaValueType.Integer : return typeof (int);
 381                         case GdaValueType.Single : return typeof (float);
 382                         case GdaValueType.Smallint : return typeof (byte);
 383                         case GdaValueType.String : return typeof (string);
 384                         case GdaValueType.Time : return typeof (DateTime);
 385                         case GdaValueType.Timestamp : return typeof (DateTime);
 386                         case GdaValueType.Tinyint : return typeof (byte);
 387                         }
 388
 389                         return typeof(string); // default
 390                 }
 391
 392                 public
 393                 override
 394                 float GetFloat (int ordinal)
 395                 {
 396                         IntPtr value;
 397
 398                         if (currentResult == -1)
 399                                 throw new InvalidCastException ();
 400
 401                         value = libgda.gda_data_model_get_value_at ((IntPtr) gdaResults[currentResult],
 402                                 ordinal, currentRow);
 403                         if (value == IntPtr.Zero)
 404                                 throw new InvalidCastException ();
 405
 406                         if (libgda.gda_value_get_type (value) != GdaValueType.Single)
 407                                 throw new InvalidCastException ();
 408                         return libgda.gda_value_get_single (value);
 409                 }
 410
 411                 [MonoTODO]
 412                 public
 413                 override
 414                 Guid GetGuid (int ordinal)
 415                 {
 416                         throw new NotImplementedException ();
 417                 }
 418
 419                 public
 420                 override
 421                 short GetInt16 (int ordinal)
 422                 {
 423                         IntPtr value;
 424
 425                         if (currentResult == -1)
 426                                 throw new InvalidCastException ();
 427
 428                         value = libgda.gda_data_model_get_value_at ((IntPtr) gdaResults[currentResult],
 429                                 ordinal, currentRow);
 430                         if (value == IntPtr.Zero)
 431                                 throw new InvalidCastException ();
 432
 433                         if (libgda.gda_value_get_type (value) != GdaValueType.Smallint)
 434                                 throw new InvalidCastException ();
 435                         return (short) libgda.gda_value_get_smallint (value);
 436                 }
 437
 438                 public
 439                 override
 440                 int GetInt32 (int ordinal)
 441                 {
 442                         IntPtr value;
 443
 444                         if (currentResult == -1)
 445                                 throw new InvalidCastException ();
 446
 447                         value = libgda.gda_data_model_get_value_at ((IntPtr) gdaResults[currentResult],
 448                                 ordinal, currentRow);
 449                         if (value == IntPtr.Zero)
 450                                 throw new InvalidCastException ();
 451
 452                         if (libgda.gda_value_get_type (value) != GdaValueType.Integer)
 453                                 throw new InvalidCastException ();
 454                         return libgda.gda_value_get_integer (value);
 455                 }
 456
 457                 public
 458                 override
 459                 long GetInt64 (int ordinal)
 460                 {
 461                         IntPtr value;
 462
 463                         if (currentResult == -1)
 464                                 throw new InvalidCastException ();
 465
 466                         value = libgda.gda_data_model_get_value_at ((IntPtr) gdaResults[currentResult],
 467                                 ordinal, currentRow);
 468                         if (value == IntPtr.Zero)
 469                                 throw new InvalidCastException ();
 470
 471                         if (libgda.gda_value_get_type (value) != GdaValueType.Bigint)
 472                                 throw new InvalidCastException ();
 473                         return libgda.gda_value_get_bigint (value);
 474                 }
 475
 476                 public
 477                 override
 478                 string GetName (int index)
 479                 {
 480                         if (currentResult == -1)
 481                                 return null;
 482
 483                         return libgda.gda_data_model_get_column_title (
 484                                 (IntPtr) gdaResults[currentResult], index);
 485                 }
 486
 487                 public
 488                 override
 489                 int GetOrdinal (string name)
 490                 {
 491                         if (currentResult == -1)
 492                                 throw new IndexOutOfRangeException ();
 493
 494                         for (int i = 0; i < FieldCount; i++) {
 495                                 if (GetName (i) == name)
 496                                         return i;
 497                         }
 498
 499                         throw new IndexOutOfRangeException ();
 500                 }
 501
 502                 public
 503                 override
 504                 DataTable GetSchemaTable ()
 505                 {
 506                         DataTable dataTableSchema = null;
 507                         // Only Results from SQL SELECT Queries
 508                         // get a DataTable for schema of the result
 509                         // otherwise, DataTable is null reference
 510                         if(this.FieldCount > 0) {
 511
 512                                 IntPtr attrs;
 513                                 GdaValueType gdaType;
 514                                 long columnSize = 0;
 515
 516                                 if (currentResult == -1) {
 517                                         // FIXME: throw an exception?
 518 #if DEBUG_OleDbDataReader
 519                                         Console.WriteLine("Error: current result -1");
 520 #endif
 521                                         return null;
 522                                 }
 523
 524                                 dataTableSchema = new DataTable ();
 525
 526                                 dataTableSchema.Columns.Add ("ColumnName", typeof (string));
 527                                 dataTableSchema.Columns.Add ("ColumnOrdinal", typeof (int));
 528                                 dataTableSchema.Columns.Add ("ColumnSize", typeof (int));
 529                                 dataTableSchema.Columns.Add ("NumericPrecision", typeof (int));
 530                                 dataTableSchema.Columns.Add ("NumericScale", typeof (int));
 531                                 dataTableSchema.Columns.Add ("IsUnique", typeof (bool));
 532                                 dataTableSchema.Columns.Add ("IsKey", typeof (bool));
 533                                 DataColumn dc = dataTableSchema.Columns["IsKey"];
 534                                 dc.AllowDBNull = true; // IsKey can have a DBNull
 535                                 dataTableSchema.Columns.Add ("BaseCatalogName", typeof (string));
 536                                 dataTableSchema.Columns.Add ("BaseColumnName", typeof (string));
 537                                 dataTableSchema.Columns.Add ("BaseSchemaName", typeof (string));
 538                                 dataTableSchema.Columns.Add ("BaseTableName", typeof (string));
 539                                 dataTableSchema.Columns.Add ("DataType", typeof(Type));
 540                                 dataTableSchema.Columns.Add ("AllowDBNull", typeof (bool));
 541                                 dataTableSchema.Columns.Add ("ProviderType", typeof (int));
 542                                 dataTableSchema.Columns.Add ("IsAliased", typeof (bool));
 543                                 dataTableSchema.Columns.Add ("IsExpression", typeof (bool));
 544                                 dataTableSchema.Columns.Add ("IsIdentity", typeof (bool));
 545                                 dataTableSchema.Columns.Add ("IsAutoIncrement", typeof (bool));
 546                                 dataTableSchema.Columns.Add ("IsRowVersion", typeof (bool));
 547                                 dataTableSchema.Columns.Add ("IsHidden", typeof (bool));
 548                                 dataTableSchema.Columns.Add ("IsLong", typeof (bool));
 549                                 dataTableSchema.Columns.Add ("IsReadOnly", typeof (bool));
 550
 551                                 DataRow schemaRow;
 552
 553                                 for (int i = 0; i < this.FieldCount; i += 1 ) {
 554
 555                                         schemaRow = dataTableSchema.NewRow ();
 556
 557                                         attrs = libgda.gda_data_model_describe_column ((IntPtr) gdaResults[currentResult],
 558                                                 i);
 559                                         if (attrs == IntPtr.Zero){
 560                                                 // FIXME: throw exception
 561 #if DEBUG_OleDbDataReader
 562                                                 Console.WriteLine("Error: attrs null");
 563 #endif
 564                                                 return null;
 565                                         }
 566
 567                                         gdaType = libgda.gda_field_attributes_get_gdatype (attrs);
 568                                         columnSize = libgda.gda_field_attributes_get_defined_size (attrs);
 569                                         libgda.gda_field_attributes_free (attrs);
 570
 571                                         schemaRow["ColumnName"] = this.GetName(i);
 572                                         schemaRow["ColumnOrdinal"] = i + 1;
 573
 574                                         schemaRow["ColumnSize"] = (int) columnSize;
 575                                         schemaRow["NumericPrecision"] = 0;
 576                                         schemaRow["NumericScale"] = 0;
 577                                         // TODO: need to get KeyInfo
 578                                         //if((cmdBehavior & CommandBehavior.KeyInfo) == CommandBehavior.KeyInfo) {
 579                                                 // bool IsUnique, IsKey;
 580                                                 // GetKeyInfo(field[i].Name, out IsUnique, out IsKey);
 581                                         //}
 582                                         //else {
 583                                                 schemaRow["IsUnique"] = false;
 584                                                 schemaRow["IsKey"] = DBNull.Value;
 585                                         //}
 586                                         schemaRow["BaseCatalogName"] = "";
 587
 588                                         schemaRow["BaseColumnName"] = this.GetName(i);
 589                                         schemaRow["BaseSchemaName"] = "";
 590                                         schemaRow["BaseTableName"] = "";
 591
 592                                         schemaRow["DataType"] = this.GetFieldType(i);
 593
 594                                         schemaRow["AllowDBNull"] = false;
 595
 596                                         schemaRow["ProviderType"] = (int) gdaType;
 597                                         schemaRow["IsAliased"] = false;
 598                                         schemaRow["IsExpression"] = false;
 599                                         schemaRow["IsIdentity"] = false;
 600                                         schemaRow["IsAutoIncrement"] = false;
 601                                         schemaRow["IsRowVersion"] = false;
 602                                         schemaRow["IsHidden"] = false;
 603                                         schemaRow["IsLong"] = false;
 604                                         schemaRow["IsReadOnly"] = false;
 605
 606                                         schemaRow.AcceptChanges();
 607
 608                                         dataTableSchema.Rows.Add (schemaRow);
 609                                 }
 610
 611 #if DEBUG_OleDbDataReader
 612                                 Console.WriteLine("********** DEBUG Table Schema BEGIN ************");
 613                                 foreach (DataRow myRow in dataTableSchema.Rows) {
 614                                         foreach (DataColumn myCol in dataTableSchema.Columns)
 615                                                 Console.WriteLine(myCol.ColumnName + " = " + myRow[myCol]);
 616                                         Console.WriteLine();
 617                                 }
 618                                 Console.WriteLine("********** DEBUG Table Schema END ************");
 619 #endif // DEBUG_OleDbDataReader
 620
 621                         }
 622
 623                         return dataTableSchema;
 624                 }
 625
 626                 public
 627                 override
 628                 string GetString (int ordinal)
 629                 {
 630                         IntPtr value;
 631
 632                         if (currentResult == -1)
 633                                 throw new InvalidCastException ();
 634
 635                         value = libgda.gda_data_model_get_value_at ((IntPtr) gdaResults[currentResult],
 636                                 ordinal, currentRow);
 637                         if (value == IntPtr.Zero)
 638                                 throw new InvalidCastException ();
 639
 640                         if (libgda.gda_value_get_type (value) != GdaValueType.String)
 641                                 throw new InvalidCastException ();
 642                         return libgda.gda_value_get_string (value);
 643                 }
 644
 645                 [MonoTODO]
 646                 public TimeSpan GetTimeSpan (int ordinal)
 647                 {
 648                         throw new NotImplementedException ();
 649                 }
 650
 651                 public
 652                 override
 653                 object GetValue (int ordinal)
 654                 {
 655                         IntPtr value;
 656                         GdaValueType type;
 657
 658                         if (currentResult == -1)
 659                                 throw new IndexOutOfRangeException ();
 660
 661                         value = libgda.gda_data_model_get_value_at ((IntPtr) gdaResults[currentResult],
 662                                 ordinal, currentRow);
 663                         if (value == IntPtr.Zero)
 664                                 throw new IndexOutOfRangeException ();
 665
 666                         type = libgda.gda_value_get_type (value);
 667                         switch (type) {
 668                         case GdaValueType.Bigint : return GetInt64 (ordinal);
 669                         case GdaValueType.Boolean : return GetBoolean (ordinal);
 670                         case GdaValueType.Date : return GetDateTime (ordinal);
 671                         case GdaValueType.Double : return GetDouble (ordinal);
 672                         case GdaValueType.Integer : return GetInt32 (ordinal);
 673                         case GdaValueType.Single : return GetFloat (ordinal);
 674                         case GdaValueType.Smallint : return GetByte (ordinal);
 675                         case GdaValueType.String : return GetString (ordinal);
 676                         case GdaValueType.Time : return GetDateTime (ordinal);
 677                         case GdaValueType.Timestamp : return GetDateTime (ordinal);
 678                         case GdaValueType.Tinyint : return GetByte (ordinal);
 679                         }
 680
 681                         return (object) libgda.gda_value_stringify (value);
 682                 }
 683
 684                 [MonoTODO]
 685                 public
 686                 override
 687                 int GetValues (object[] values)
 688                 {
 689                         throw new NotImplementedException ();
 690                 }
 691
 692
 693                 public override IEnumerator GetEnumerator()
 694                 {
 695                         return new DbEnumerator(this);
 696                 }
 697
 698                 public
 699                 override
 700                 bool IsDBNull (int ordinal)
 701                 {
 702                         IntPtr value;
 703
 704                         if (currentResult == -1)
 705                                 throw new IndexOutOfRangeException ();
 706
 707                         value = libgda.gda_data_model_get_value_at ((IntPtr) gdaResults[currentResult],
 708                                 ordinal, currentRow);
 709                         if (value == IntPtr.Zero)
 710                                 throw new IndexOutOfRangeException ();
 711
 712                         return libgda.gda_value_is_null (value);
 713                 }
 714
 715                 public
 716                 override
 717                 bool NextResult ()
 718                 {
 719                         int i = currentResult + 1;
 720                         if (i >= 0 && i < gdaResults.Count) {
 721                                 currentResult++;
 722                                 return true;
 723                         }
 724
 725                         return false;
 726                 }
 727
 728                 public
 729                 override
 730                 bool Read ()
 731                 {
 732                         if (currentResult < 0 || currentResult >= gdaResults.Count)
 733                                 return false;
 734
 735                         currentRow++;
 736                         if (currentRow < libgda.gda_data_model_get_n_rows ((IntPtr) gdaResults[currentResult]))
 737                                 return true;
 738
 739                         return false;
 740                 }
 741
 742                 #endregion
 743
 744                 #region Destructors
 745
 746                 private new void Dispose (bool disposing)
 747                 {
 748                         if (!this.disposed) {
 749                                 if (disposing) {
 750                                         // release any managed resources
 751                                         command = null;
 752                                         GC.SuppressFinalize (this);
 753                                 }
 754                                 // release any unmanaged resources
 755                                 if (gdaResults != null) {
 756                                         gdaResults.Clear ();
 757                                         gdaResults = null;
 758                                 }
 759
 760                                 // close any handles
 761                                 if (open)
 762                                         Close ();
 763
 764                                 this.disposed = true;
 765                         }
 766                 }
 767
 768                 void IDisposable.Dispose() {
 769                         Dispose (true);
 770                 }
 771
 772                 #endregion // Destructors
 773         }
 774 }