mcs/class/Mono.Data.SqliteClient/Mono.Data.SqliteClient/SqliteDataReader.cs

   1 //
   2 // Mono.Data.SqliteClient.SqliteDataReader.cs
   3 //
   4 // Provides a means of reading a forward-only stream of rows from a Sqlite
   5 // database file.
   6 //
   7 // Author(s): Vladimir Vukicevic  <vladimir@pobox.com>
   8 //            Everaldo Canuto  <everaldo_canuto@yahoo.com.br>
   9 //
  10 // Copyright (C) 2002  Vladimir Vukicevic
  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;
  33 using System.Runtime.InteropServices;
  34 using System.Collections;
  35 using System.Data;
  36 using System.Data.Common;
  37
  38 namespace Mono.Data.SqliteClient
  39 {
  40         public class SqliteDataReader : MarshalByRefObject, IEnumerable, IDataReader, IDisposable, IDataRecord
  41         {
  42
  43                 #region Fields
  44
  45                 private SqliteCommand command;
  46                 private ArrayList rows;
  47                 private ArrayList columns;
  48                 private Hashtable column_names;
  49                 private int current_row;
  50                 private bool closed;
  51                 private bool reading;
  52                 private int records_affected;
  53
  54                 #endregion
  55
  56                 #region Constructors and destructors
  57
  58                 internal SqliteDataReader (SqliteCommand cmd)
  59                 {
  60                         command = cmd;
  61                         rows = new ArrayList ();
  62                         columns = new ArrayList ();
  63                         column_names = new Hashtable ();
  64                         closed = false;
  65                         current_row = -1;
  66                         reading = true;
  67                 }
  68
  69                 #endregion
  70
  71                 #region Properties
  72
  73                 public int Depth {
  74                         get { return 0; }
  75                 }
  76
  77                 public int FieldCount {
  78                         get { return columns.Count; }
  79                 }
  80
  81                 public object this[string name] {
  82                         get { return ((ArrayList) rows[current_row])[(int) column_names[name]]; }
  83                 }
  84
  85                 public object this[int i] {
  86                         get { return ((ArrayList) rows[current_row])[i]; }
  87                 }
  88
  89                 public bool IsClosed {
  90                         get { return closed; }
  91                 }
  92
  93                 public int RecordsAffected {
  94                         get { return records_affected; }
  95                 }
  96
  97                 #endregion
  98
  99                 #region Internal Methods
 100
 101                 internal unsafe int SqliteCallback (ref object o, int argc, sbyte **argv, sbyte **colnames)
 102                 {
 103                         // cache names of columns if we need to
 104                         if (column_names.Count == 0) {
 105                                 for (int i = 0; i < argc; i++) {
 106                                         string col = new String (colnames[i]);
 107                                         columns.Add (col);
 108                                         column_names[col.ToLower ()] = i;
 109                                 }
 110                         }
 111
 112                         ArrayList data_row = new ArrayList (argc);
 113                         for (int i = 0; i < argc; i++) {
 114                                 if (argv[i] != ((sbyte *)0)) {
 115                                         data_row.Add(new String (argv[i]));
 116                                 } else {
 117                                         data_row.Add(null);
 118                                 }
 119                         }
 120                         rows.Add (data_row);
 121                         return 0;
 122                 }
 123
 124                 internal void ReadingDone ()
 125                 {
 126                         records_affected = command.NumChanges ();
 127                         reading = false;
 128                 }
 129
 130                 #endregion
 131
 132                 #region  Public Methods
 133
 134                 public void Close ()
 135                 {
 136                         closed = true;
 137                 }
 138
 139                 public void Dispose ()
 140                 {
 141                         Close ();
 142                 }
 143
 144                 IEnumerator IEnumerable.GetEnumerator ()
 145                 {
 146                         return new DbEnumerator (this);
 147                 }
 148
 149                 public DataTable GetSchemaTable ()
 150                 {
 151                         DataTable dataTableSchema = new DataTable ();
 152
 153                         dataTableSchema.Columns.Add ("ColumnName", typeof (String));
 154                         dataTableSchema.Columns.Add ("ColumnOrdinal", typeof (Int32));
 155                         dataTableSchema.Columns.Add ("ColumnSize", typeof (Int32));
 156                         dataTableSchema.Columns.Add ("NumericPrecision", typeof (Int32));
 157                         dataTableSchema.Columns.Add ("NumericScale", typeof (Int32));
 158                         dataTableSchema.Columns.Add ("IsUnique", typeof (Boolean));
 159                         dataTableSchema.Columns.Add ("IsKey", typeof (Boolean));
 160                         dataTableSchema.Columns.Add ("BaseCatalogName", typeof (String));
 161                         dataTableSchema.Columns.Add ("BaseColumnName", typeof (String));
 162                         dataTableSchema.Columns.Add ("BaseSchemaName", typeof (String));
 163                         dataTableSchema.Columns.Add ("BaseTableName", typeof (String));
 164                         dataTableSchema.Columns.Add ("DataType", typeof(Type));
 165                         dataTableSchema.Columns.Add ("AllowDBNull", typeof (Boolean));
 166                         dataTableSchema.Columns.Add ("ProviderType", typeof (Int32));
 167                         dataTableSchema.Columns.Add ("IsAliased", typeof (Boolean));
 168                         dataTableSchema.Columns.Add ("IsExpression", typeof (Boolean));
 169                         dataTableSchema.Columns.Add ("IsIdentity", typeof (Boolean));
 170                         dataTableSchema.Columns.Add ("IsAutoIncrement", typeof (Boolean));
 171                         dataTableSchema.Columns.Add ("IsRowVersion", typeof (Boolean));
 172                         dataTableSchema.Columns.Add ("IsHidden", typeof (Boolean));
 173                         dataTableSchema.Columns.Add ("IsLong", typeof (Boolean));
 174                         dataTableSchema.Columns.Add ("IsReadOnly", typeof (Boolean));
 175
 176                         dataTableSchema.BeginLoadData();
 177                         for (int i = 0; i < this.FieldCount; i += 1 ) {
 178
 179                                 DataRow schemaRow = dataTableSchema.NewRow ();
 180
 181                                 schemaRow["ColumnName"] = columns[i];
 182                                 schemaRow["ColumnOrdinal"] = i;
 183                                 schemaRow["ColumnSize"] = 0;
 184                                 schemaRow["NumericPrecision"] = 0;
 185                                 schemaRow["NumericScale"] = 0;
 186                                 schemaRow["IsUnique"] = false;
 187                                 schemaRow["IsKey"] = false;
 188                                 schemaRow["BaseCatalogName"] = "";
 189                                 schemaRow["BaseColumnName"] = columns[i];
 190                                 schemaRow["BaseSchemaName"] = "";
 191                                 schemaRow["BaseTableName"] = "";
 192                                 schemaRow["DataType"] = typeof(string);
 193                                 schemaRow["AllowDBNull"] = true;
 194                                 schemaRow["ProviderType"] = 0;
 195                                 schemaRow["IsAliased"] = false;
 196                                 schemaRow["IsExpression"] = false;
 197                                 schemaRow["IsIdentity"] = false;
 198                                 schemaRow["IsAutoIncrement"] = false;
 199                                 schemaRow["IsRowVersion"] = false;
 200                                 schemaRow["IsHidden"] = false;
 201                                 schemaRow["IsLong"] = false;
 202                                 schemaRow["IsReadOnly"] = false;
 203
 204                                 dataTableSchema.Rows.Add (schemaRow);
 205                                 schemaRow.AcceptChanges();
 206                         }
 207                         dataTableSchema.EndLoadData();
 208
 209                         return dataTableSchema;
 210                 }
 211
 212                 public bool NextResult ()
 213                 {
 214                         current_row++;
 215
 216                         return (current_row < rows.Count);
 217                 }
 218
 219                 public bool Read ()
 220                 {
 221                         return NextResult ();
 222                 }
 223
 224                 #endregion
 225
 226                 #region IDataRecord getters
 227
 228                 public bool GetBoolean (int i)
 229                 {
 230                         return Convert.ToBoolean ((string) ((ArrayList) rows[current_row])[i]);
 231                 }
 232
 233                 public byte GetByte (int i)
 234                 {
 235                         return Convert.ToByte ((string) ((ArrayList) rows[current_row])[i]);
 236                 }
 237
 238                 public long GetBytes (int i, long fieldOffset, byte[] buffer, int bufferOffset, int length)
 239                 {
 240                         throw new NotImplementedException ();
 241                 }
 242
 243                 public char GetChar (int i)
 244                 {
 245                         return Convert.ToChar ((string) ((ArrayList) rows[current_row])[i]);
 246                 }
 247
 248                 public long GetChars (int i, long fieldOffset, char[] buffer, int bufferOffset, int length)
 249                 {
 250                         throw new NotImplementedException ();
 251                 }
 252
 253                 public IDataReader GetData (int i)
 254                 {
 255                         throw new NotImplementedException ();
 256                 }
 257
 258                 public string GetDataTypeName (int i)
 259                 {
 260                         return "text"; // SQL Lite data type
 261                 }
 262
 263                 public DateTime GetDateTime (int i)
 264                 {
 265                         return Convert.ToDateTime ((string) ((ArrayList) rows[current_row])[i]);
 266                 }
 267
 268                 public decimal GetDecimal (int i)
 269                 {
 270                         return Convert.ToDecimal ((string) ((ArrayList) rows[current_row])[i]);
 271                 }
 272
 273                 public double GetDouble (int i)
 274                 {
 275                         return Convert.ToDouble ((string) ((ArrayList) rows[current_row])[i]);
 276                 }
 277
 278                 public Type GetFieldType (int i)
 279                 {
 280                         return System.Type.GetType ("System.String"); // .NET data type
 281                 }
 282
 283                 public float GetFloat (int i)
 284                 {
 285                         return Convert.ToSingle ((string) ((ArrayList) rows[current_row])[i]);
 286                 }
 287
 288                 public Guid GetGuid (int i)
 289                 {
 290                         throw new NotImplementedException ();
 291                 }
 292
 293                 public short GetInt16 (int i)
 294                 {
 295                         return Convert.ToInt16 ((string) ((ArrayList) rows[current_row])[i]);
 296                 }
 297
 298                 public int GetInt32 (int i)
 299                 {
 300                         return Convert.ToInt32 ((string) ((ArrayList) rows[current_row])[i]);
 301                 }
 302
 303                 public long GetInt64 (int i)
 304                 {
 305                         return Convert.ToInt64 ((string) ((ArrayList) rows[current_row])[i]);
 306                 }
 307
 308                 public string GetName (int i)
 309                 {
 310                         return (string) columns[i];
 311                 }
 312
 313                 public int GetOrdinal (string name)
 314                 {
 315                         return (int) column_names[name];
 316                 }
 317
 318                 public string GetString (int i)
 319                 {
 320                         return ((string) ((ArrayList) rows[current_row])[i]);
 321                 }
 322
 323                 public object GetValue (int i)
 324                 {
 325                         return ((ArrayList) rows[current_row])[i];
 326                 }
 327
 328                 public int GetValues (object[] values)
 329                 {
 330                         int num_to_fill = System.Math.Min (values.Length, columns.Count);
 331                         for (int i = 0; i < num_to_fill; i++) {
 332                                 if (((ArrayList) rows[current_row])[i] != null) {
 333                                         values[i] = ((ArrayList) rows[current_row])[i];
 334                                 } else {
 335                                         values[i] = DBNull.Value;
 336                                 }
 337                         }
 338                         return num_to_fill;
 339                 }
 340
 341                 public bool IsDBNull (int i)
 342                 {
 343                         return (((ArrayList) rows[current_row])[i] == null);
 344                 }
 345
 346                 #endregion
 347         }
 348 }