mcs/class/Npgsql/Npgsql/NpgsqlDataReader.cs

   1 \r
   2 // Npgsql.NpgsqlDataReader.cs\r
   3 // \r
   4 // Author:\r
   5 //      Francisco Jr. (fxjrlists@yahoo.com.br)\r
   6 //\r
   7 //      Copyright (C) 2002 The Npgsql Development Team\r
   8 //\r
   9 \r
  10 // This library is free software; you can redistribute it and/or\r
  11 // modify it under the terms of the GNU Lesser General Public\r
  12 // License as published by the Free Software Foundation; either\r
  13 // version 2.1 of the License, or (at your option) any later version.\r
  14 // \r
  15 // This library is distributed in the hope that it will be useful,\r
  16 // but WITHOUT ANY WARRANTY; without even the implied warranty of\r
  17 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU\r
  18 // Lesser General Public License for more details.\r
  19 // \r
  20 // You should have received a copy of the GNU Lesser General Public\r
  21 // License along with this library; if not, write to the Free Software\r
  22 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA\r
  23 \r
  24 using System;\r
  25 using System.Data;\r
  26 using System.Collections;\r
  27 \r
  28 \r
  29 namespace Npgsql\r
  30 {       \r
  31         public class NpgsqlDataReader : IDataReader, IEnumerable\r
  32         {\r
  33           private NpgsqlConnection      _connection;\r
  34         private ArrayList                               _resultsets;\r
  35                 private ArrayList                                       _responses;\r
  36           private Int32                                                 _rowIndex;\r
  37                 private Int32                                                   _resultsetIndex;\r
  38                 private NpgsqlResultSet         _currentResultset;\r
  39                 private DataTable                                       _currentResultsetSchema;\r
  40                 \r
  41                 \r
  42                 // Logging related values\r
  43     private static readonly String CLASSNAME = "NpgsqlDataReader";\r
  44                 \r
  45           internal NpgsqlDataReader( ArrayList resultsets, ArrayList responses, NpgsqlConnection connection)\r
  46           {\r
  47             _resultsets                                 = resultsets;\r
  48                 _responses                                      = responses;\r
  49                 _connection                             = connection;\r
  50                 _rowIndex                                               = -1;\r
  51                 _resultsetIndex                 = 0;\r
  52                 \r
  53                 _currentResultset       = (NpgsqlResultSet)_resultsets[_resultsetIndex];\r
  54                 \r
  55                 \r
  56                 \r
  57           }\r
  58           \r
  59           private Boolean CanRead()\r
  60           {\r
  61                 NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".CanRead() ", LogLevel.Debug);\r
  62                 /*if (_currentResultset == null)\r
  63                         return false;*/\r
  64                 return (_currentResultset != null);\r
  65                 \r
  66           }\r
  67           \r
  68           \r
  69           public void Dispose()\r
  70           {\r
  71                 \r
  72           }\r
  73 \r
  74           public Int32 Depth \r
  75           {\r
  76                 get\r
  77                 {\r
  78                         NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".get_Depth() ", LogLevel.Debug);\r
  79                         return 0;\r
  80                 }\r
  81           }\r
  82           \r
  83           public Boolean IsClosed\r
  84           {\r
  85                 get\r
  86                 {\r
  87                         NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".get_IsClosed()", LogLevel.Debug);\r
  88                         return false; \r
  89                 }\r
  90           }\r
  91           \r
  92           public Int32 RecordsAffected \r
  93           {\r
  94                 get\r
  95                 {\r
  96                         NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".get_RecordsAffected()", LogLevel.Debug);\r
  97                         \r
  98                         /*if (_currentResultset == null)\r
  99                                 return 0;       //[FIXME] Get the actual number of rows deleted, updated or inserted.\r
 100                         return -1;\r
 101                         */\r
 102                         \r
 103                         if (CanRead())\r
 104                                 return -1;\r
 105                         \r
 106                         String[] ret_string_tokens = ((String)_responses[_resultsetIndex]).Split(null); // whitespace separator.\r
 107                                 \r
 108                                 return Int32.Parse(ret_string_tokens[ret_string_tokens.Length - 1]);\r
 109                 }\r
 110             \r
 111           }\r
 112           \r
 113           public void Close()\r
 114           {\r
 115             \r
 116           }\r
 117           \r
 118           public Boolean NextResult()\r
 119           {\r
 120                 NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".NextResult()", LogLevel.Debug);\r
 121             //throw new NotImplementedException();\r
 122                 \r
 123                 //[FIXME] Should the currentResultset not be modified\r
 124                 // in case there aren't any more resultsets?\r
 125                 // SqlClient modify to a invalid resultset and throws exceptions\r
 126                 // when trying to access any data.\r
 127                 \r
 128                                 \r
 129                 if((_resultsetIndex + 1) < _resultsets.Count)\r
 130                 {\r
 131                         _resultsetIndex++;\r
 132                         _rowIndex = -1;\r
 133                         _currentResultset = (NpgsqlResultSet)_resultsets[_resultsetIndex];\r
 134                         return true;\r
 135                 }\r
 136                 else\r
 137                         return false;\r
 138                 \r
 139           }\r
 140           \r
 141           public Boolean Read()\r
 142           {\r
 143                 NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".Read()", LogLevel.Debug);\r
 144                 \r
 145                 if (!CanRead())\r
 146                         return false;\r
 147                 \r
 148             _rowIndex++;\r
 149                 return (_rowIndex < _currentResultset.Count);\r
 150           }\r
 151           \r
 152           public DataTable GetSchemaTable()\r
 153           {\r
 154                 NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".GetSchemaTable()", LogLevel.Debug);\r
 155             //throw new NotImplementedException();\r
 156                 \r
 157                 if (!CanRead())\r
 158                         return null; //[FIXME] Should we return null or throw an exception??\r
 159                 \r
 160                 if(_currentResultsetSchema == null)\r
 161                         _currentResultsetSchema = GetResultsetSchema();\r
 162                 \r
 163                 return _currentResultsetSchema;\r
 164                 \r
 165           }\r
 166           \r
 167           \r
 168           public Int32 FieldCount\r
 169           {\r
 170                 get\r
 171                 {\r
 172                         \r
 173                         NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".get_FieldCount()", LogLevel.Debug);\r
 174                         //return ((_currentResultset == null) ? 0 : _currentResultset.RowDescription.NumFields);\r
 175                         if (CanRead())\r
 176                                 return _currentResultset.RowDescription.NumFields;\r
 177                         else\r
 178                                 return -1;\r
 179                                 \r
 180                 }\r
 181             \r
 182           }\r
 183           \r
 184           public String GetName(Int32 i)\r
 185           {\r
 186             //throw new NotImplementedException();\r
 187                 NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".GetName(Int32)", LogLevel.Debug);\r
 188                 \r
 189                 if (CanRead())\r
 190                         return _currentResultset.RowDescription[i].name;\r
 191                 else\r
 192                         return String.Empty;\r
 193           }\r
 194           \r
 195           public String GetDataTypeName(Int32 i)\r
 196           {\r
 197                   // FIXME: have a type name instead of the oid\r
 198                  return (_currentResultset.RowDescription[i].type_oid).ToString();\r
 199           }\r
 200           \r
 201           public Type GetFieldType(Int32 i)\r
 202           {\r
 203                 NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".GetFieldType(Int32)", LogLevel.Debug);\r
 204                 //[FIXME] hack\r
 205                         \r
 206                 return Type.GetType(PGUtil.GetSystemTypeFromDbType(_currentResultset.RowDescription[i].type_oid));\r
 207           }\r
 208           \r
 209           public Object GetValue(Int32 i)\r
 210           {\r
 211                 NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".GetValue(Int32)", LogLevel.Debug);\r
 212                 if (i < 0 || _rowIndex < 0)\r
 213                         throw new InvalidOperationException("Cannot read data.");\r
 214                 return ((NpgsqlAsciiRow)_currentResultset[_rowIndex])[i];\r
 215           }\r
 216           \r
 217           public Int32 GetValues(Object[] values)\r
 218           {\r
 219                 NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".GetValues(Object[])", LogLevel.Debug);\r
 220                 \r
 221                 // Only the number of elements in the array are filled.\r
 222                 // It's also possible to pass an array with more that FieldCount elements.\r
 223                 Int32 maxColumnIndex = (values.Length < FieldCount) ? values.Length : FieldCount;\r
 224                 \r
 225                 for (Int32 i = 0; i < maxColumnIndex; i++)\r
 226                         values[i] = GetValue(i);\r
 227                 \r
 228                 return maxColumnIndex;\r
 229                 \r
 230           }\r
 231           \r
 232           public Int32 GetOrdinal(String name)\r
 233           {\r
 234                 return _currentResultset.RowDescription.FieldIndex(name);\r
 235           }\r
 236           \r
 237           public Object this [ Int32 i ]\r
 238           {\r
 239                 get\r
 240                 {\r
 241                         NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".this[Int32]", LogLevel.Debug);\r
 242                         return GetValue(i);\r
 243                 }\r
 244           }\r
 245           \r
 246           public Object this [ String name ]\r
 247           {\r
 248                 get\r
 249                 {\r
 250                         //throw new NotImplementedException();\r
 251                         NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".this[String]", LogLevel.Debug);\r
 252                         return GetValue(_currentResultset.RowDescription.FieldIndex(name));\r
 253                 }\r
 254           }\r
 255           \r
 256           public Boolean GetBoolean(Int32 i)\r
 257           {\r
 258             // Should this be done using the GetValue directly and not by converting to String\r
 259                 // and parsing from there?\r
 260                 NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".GetBoolean(Int32)", LogLevel.Debug);\r
 261                 \r
 262                 switch ((String) this[i])\r
 263                 {\r
 264                         case "t":\r
 265                                 return true;\r
 266                                 \r
 267                         case "f":\r
 268                                 return false;\r
 269                                 \r
 270                         default:\r
 271                                 throw new System.InvalidCastException();\r
 272                         \r
 273                 }\r
 274                 \r
 275           }\r
 276           \r
 277           public Byte GetByte(Int32 i)\r
 278           {\r
 279             throw new NotImplementedException();\r
 280           }\r
 281           \r
 282           public Int64 GetBytes(Int32 i, Int64 fieldOffset, Byte[] buffer, Int32 bufferoffset, Int32 length)\r
 283           {\r
 284             throw new NotImplementedException();\r
 285           }\r
 286           \r
 287           public Char GetChar(Int32 i)\r
 288           {\r
 289             throw new NotImplementedException();\r
 290           }\r
 291           \r
 292           public Int64 GetChars(Int32 i, Int64 fieldoffset, Char[] buffer, Int32 bufferoffset, Int32 length)\r
 293           {\r
 294                         String          str;\r
 295 \r
 296                         str = GetString(i);\r
 297                 if (buffer == null)\r
 298                         return str.Length;\r
 299                 \r
 300                         str.ToCharArray(bufferoffset, length).CopyTo(buffer, 0);\r
 301                         return buffer.GetLength(0);\r
 302           }\r
 303           \r
 304           public Guid GetGuid(Int32 i)\r
 305           {\r
 306             throw new NotImplementedException();\r
 307           }\r
 308           \r
 309           public Int16 GetInt16(Int32 i)\r
 310           {\r
 311             // Should this be done using the GetValue directly and not by converting to String\r
 312                 // and parsing from there?\r
 313                 NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".GetInt16(Int32)", LogLevel.Debug);\r
 314                 try\r
 315                 {\r
 316                     return Int16.Parse((String) this[i]);\r
 317                 } catch (System.FormatException)\r
 318                 {\r
 319                         throw new System.InvalidCastException();\r
 320                 }\r
 321                 \r
 322 \r
 323           }\r
 324           \r
 325           public Int32 GetInt32(Int32 i)\r
 326           {\r
 327             // Should this be done using the GetValue directly and not by converting to String\r
 328                 // and parsing from there?\r
 329                 NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".GetInt32(Int32)", LogLevel.Debug);\r
 330                 try\r
 331                 {\r
 332                     return Int32.Parse((String) this[i]);\r
 333                 } catch (System.FormatException)\r
 334                 {\r
 335                         throw new System.InvalidCastException();\r
 336                 }\r
 337                 \r
 338 \r
 339           }\r
 340           \r
 341           public Int64 GetInt64(Int32 i)\r
 342           {\r
 343             // Should this be done using the GetValue directly and not by converting to String\r
 344                 // and parsing from there?\r
 345                 NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".GetInt64(Int32)", LogLevel.Debug);\r
 346                 try\r
 347                 {\r
 348                     return Int64.Parse((String) this[i]);\r
 349                 } catch (System.FormatException)\r
 350                 {\r
 351                         throw new System.InvalidCastException();\r
 352                 }\r
 353           }\r
 354           \r
 355           public Single GetFloat(Int32 i)\r
 356           {\r
 357             // Should this be done using the GetValue directly and not by converting to String\r
 358                 // and parsing from there?\r
 359                 NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".GetFloat(Int32)", LogLevel.Debug);\r
 360                 try\r
 361                 {\r
 362                     return Single.Parse((String) this[i]);\r
 363                 } catch (System.FormatException)\r
 364                 {\r
 365                         throw new System.InvalidCastException();\r
 366                 }\r
 367           }\r
 368           \r
 369           public Double GetDouble(Int32 i)\r
 370           {\r
 371             // Should this be done using the GetValue directly and not by converting to String\r
 372                 // and parsing from there?\r
 373                 NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".GetDouble(Int32)", LogLevel.Debug);\r
 374                 try\r
 375                 {\r
 376                     return Double.Parse((String) this[i]);\r
 377                 } catch (System.FormatException)\r
 378                 {\r
 379                         throw new System.InvalidCastException();\r
 380                 }\r
 381           }\r
 382           \r
 383           public String GetString(Int32 i)\r
 384           {\r
 385                 NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".GetString(Int32)", LogLevel.Debug);\r
 386             return (String) GetValue(i);\r
 387           }\r
 388           \r
 389           public Decimal GetDecimal(Int32 i)\r
 390           {\r
 391             // Should this be done using the GetValue directly and not by converting to String\r
 392                 // and parsing from there?\r
 393                 NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".GetDecimal(Int32)", LogLevel.Debug);\r
 394                 try\r
 395                 {\r
 396                     return Decimal.Parse((String) this[i]);\r
 397                 } catch (System.FormatException)\r
 398                 {\r
 399                         throw new System.InvalidCastException();\r
 400                 }\r
 401           }\r
 402           \r
 403           public DateTime GetDateTime(Int32 i)\r
 404           {\r
 405                   // Should this be done using the GetValue directly and not by converting to String\r
 406                   // and parsing from there?\r
 407                   NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".GetInt32(Int32)", LogLevel.Debug);\r
 408                   try {\r
 409                           return DateTime.ParseExact((string) this[i], "dd/MM/yyyy", null);
 410                   } catch (System.FormatException) {\r
 411                           throw new System.InvalidCastException();\r
 412                   }\r
 413           }\r
 414           \r
 415           public IDataReader GetData(Int32 i)\r
 416           {\r
 417             throw new NotImplementedException();\r
 418           }\r
 419           \r
 420           public Boolean IsDBNull(Int32 i)\r
 421           {\r
 422                 //throw new NotImplementedException();\r
 423                 \r
 424                 return ((NpgsqlAsciiRow)_currentResultset[_rowIndex]).IsNull(i);\r
 425           }\r
 426 \r
 427                 private DataTable GetResultsetSchema()\r
 428                 {\r
 429                         DataTable result = null;\r
 430                         NpgsqlEventLog.LogMsg("Entering " + CLASSNAME + ".GetResultsetSchema()", LogLevel.Debug);\r
 431                         // [FIXME] For now, just support fields name.\r
 432                         \r
 433                         NpgsqlRowDescription rd = _currentResultset.RowDescription;\r
 434                         Int16 numFields = rd.NumFields;\r
 435                         if(numFields > 0) {\r
 436                                 result = new DataTable("SchemaTable");          \r
 437 \r
 438                                 result.Columns.Add ("ColumnName", typeof (string));
 439                                 result.Columns.Add ("ColumnOrdinal", typeof (int));
 440                                 result.Columns.Add ("ColumnSize", typeof (int));
 441                                 result.Columns.Add ("NumericPrecision", typeof (int));
 442                                 result.Columns.Add ("NumericScale", typeof (int));
 443                                 result.Columns.Add ("IsUnique", typeof (bool));
 444                                 result.Columns.Add ("IsKey", typeof (bool));
 445                                 DataColumn dc = result.Columns["IsKey"];
 446                                 dc.AllowDBNull = true; // IsKey can have a DBNull
 447                                 result.Columns.Add ("BaseCatalogName", typeof (string));
 448                                 result.Columns.Add ("BaseColumnName", typeof (string));
 449                                 result.Columns.Add ("BaseSchemaName", typeof (string));
 450                                 result.Columns.Add ("BaseTableName", typeof (string));
 451                                 result.Columns.Add ("DataType", typeof(Type));
 452                                 result.Columns.Add ("AllowDBNull", typeof (bool));
 453                                 result.Columns.Add ("ProviderType", typeof (int));
 454                                 result.Columns.Add ("IsAliased", typeof (bool));
 455                                 result.Columns.Add ("IsExpression", typeof (bool));
 456                                 result.Columns.Add ("IsIdentity", typeof (bool));
 457                                 result.Columns.Add ("IsAutoIncrement", typeof (bool));
 458                                 result.Columns.Add ("IsRowVersion", typeof (bool));
 459                                 result.Columns.Add ("IsHidden", typeof (bool));
 460                                 result.Columns.Add ("IsLong", typeof (bool));
 461                                 result.Columns.Add ("IsReadOnly", typeof (bool));
 462 \r
 463                                 DataRow row;\r
 464                         \r
 465                                 for (Int16 i = 0; i < numFields; i++) {\r
 466                                         row = result.NewRow();\r
 467 \r
 468                                         row["ColumnName"] = GetName(i);
 469                                         row["ColumnOrdinal"] = i + 1;
 470                                         row["ColumnSize"] = (int) rd[i].type_size;
 471                                         row["NumericPrecision"] = 0;
 472                                         row["NumericScale"] = 0;
 473                                         row["IsUnique"] = false;
 474                                         row["IsKey"] = DBNull.Value;
 475                                         row["BaseCatalogName"] = "";
 476                                         row["BaseColumnName"] = GetName(i);
 477                                         row["BaseSchemaName"] = "";
 478                                         row["BaseTableName"] = "";\r
 479                                         row["DataType"] = GetFieldType(i);
 480                                         row["AllowDBNull"] = false;
 481                                         row["ProviderType"] = (int) rd[i].type_oid;
 482                                         row["IsAliased"] = false;
 483                                         row["IsExpression"] = false;
 484                                         row["IsIdentity"] = false;
 485                                         row["IsAutoIncrement"] = false;
 486                                         row["IsRowVersion"] = false;
 487                                         row["IsHidden"] = false;
 488                                         row["IsLong"] = false;
 489                                         row["IsReadOnly"] = false;\r
 490 \r
 491                                         result.Rows.Add(row);\r
 492                                 }\r
 493                         }\r
 494                         \r
 495                         return result;\r
 496                         \r
 497                 }\r
 498 \r
 499                 IEnumerator IEnumerable.GetEnumerator () {
 500                         return new System.Data.Common.DbEnumerator (this);
 501                 }\r
 502         }\r
 503 }\r