mcs/class/System.Data/System.Data.Common/DbEnumerator.cs

   1 //
   2 // System.Data.SqlClient.DbEnumerator.cs
   3 //
   4 // Author:
   5 //   Tim Coleman (tim@timcoleman.com)
   6 //
   7 // Copyright (C) Tim Coleman, 2002
   8 //
   9
  10 //
  11 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  12 //
  13 // Permission is hereby granted, free of charge, to any person obtaining
  14 // a copy of this software and associated documentation files (the
  15 // "Software"), to deal in the Software without restriction, including
  16 // without limitation the rights to use, copy, modify, merge, publish,
  17 // distribute, sublicense, and/or sell copies of the Software, and to
  18 // permit persons to whom the Software is furnished to do so, subject to
  19 // the following conditions:
  20 //
  21 // The above copyright notice and this permission notice shall be
  22 // included in all copies or substantial portions of the Software.
  23 //
  24 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  28 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  29 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  30 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  31 //
  32
  33 using System;
  34 using System.Collections;
  35 using System.ComponentModel;
  36 using System.Data;
  37
  38 namespace System.Data.Common {
  39         public class DbEnumerator : IEnumerator
  40         {
  41                 #region Fields
  42
  43                 IDataReader reader;
  44                 bool closeReader;
  45                 SchemaInfo[] schema;
  46                 FieldNameLookup lookup;
  47                 int fieldCount;
  48
  49                 #endregion // Fields
  50
  51                 #region Constructors
  52
  53                 public DbEnumerator (IDataReader reader)
  54                         : this (reader, false)
  55                 {
  56                 }
  57
  58                 public DbEnumerator (IDataReader reader, bool closeReader)
  59                 {
  60                         this.reader = reader;
  61                         this.closeReader = closeReader;
  62                         this.lookup = new FieldNameLookup ();
  63                         this.fieldCount = reader.FieldCount;
  64                         LoadSchema (reader.GetSchemaTable ());
  65                 }
  66
  67                 #endregion // Constructors
  68
  69                 #region Properties
  70
  71                 public object Current {
  72                         get {
  73                                 object[] values = new object[fieldCount];
  74                                 reader.GetValues (values);
  75                                 return new DbDataRecord (schema, values, lookup);
  76                         }
  77                 }
  78
  79                 #endregion // Properties
  80
  81                 #region Methods
  82
  83                 private void LoadSchema (DataTable schemaTable)
  84                 {
  85                         schema = new SchemaInfo [fieldCount];
  86                         int index = 0;
  87                         foreach (DataRow row in schemaTable.Rows) {
  88                                 SchemaInfo columnSchema = new SchemaInfo ();
  89
  90                                 lookup.Add ((string) row["ColumnName"]);
  91
  92                                 columnSchema.AllowDBNull = (bool) row ["AllowDBNull"];
  93                                 columnSchema.ColumnName = row ["ColumnName"].ToString ();
  94                                 columnSchema.ColumnOrdinal = (int) row ["ColumnOrdinal"];
  95                                 columnSchema.ColumnSize = (int) row ["ColumnSize"];
  96                                 columnSchema.DataTypeName = reader.GetDataTypeName (index);
  97                                 columnSchema.FieldType = reader.GetFieldType (index);
  98                                 columnSchema.IsReadOnly = (bool) row ["IsReadOnly"];
  99                                 columnSchema.TableName = row ["BaseTableName"].ToString ();
 100
 101                                 if (row ["NumericPrecision"] != DBNull.Value)
 102                                         columnSchema.NumericPrecision = Convert.ToByte (row ["NumericPrecision"]);
 103                                 else
 104                                         columnSchema.NumericPrecision = Convert.ToByte (0);
 105
 106                                 if (row ["NumericScale"] != DBNull.Value)
 107                                         columnSchema.NumericScale = Convert.ToByte (row ["NumericScale"]);
 108                                 else
 109                                         columnSchema.NumericScale = Convert.ToByte (0);
 110
 111                                 schema [index] = columnSchema;
 112                                 index += 1;
 113                         }
 114                 }
 115
 116                 public bool MoveNext ()
 117                 {
 118                         if (reader.Read ())
 119                                 return true;
 120                         if (closeReader)
 121                                 reader.Close ();
 122                         return false;
 123                 }
 124
 125                 [EditorBrowsable (EditorBrowsableState.Never)]
 126                 public void Reset ()
 127                 {
 128                         throw new NotSupportedException ();
 129                 }
 130
 131                 #endregion // Methods
 132         }
 133 }