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 using System;
  11 using System.Collections;
  12 using System.ComponentModel;
  13 using System.Data;
  14
  15 namespace System.Data.Common {
  16         public class DbEnumerator : IEnumerator
  17         {
  18                 #region Fields
  19
  20                 IDataReader reader;
  21                 bool closeReader;
  22                 SchemaInfo[] schema;
  23                 FieldNameLookup lookup;
  24                 int fieldCount;
  25
  26                 #endregion // Fields
  27
  28                 #region Constructors
  29
  30                 public DbEnumerator (IDataReader reader)
  31                         : this (reader, false)
  32                 {
  33                 }
  34
  35                 public DbEnumerator (IDataReader reader, bool closeReader)
  36                 {
  37                         this.reader = reader;
  38                         this.closeReader = closeReader;
  39                         this.lookup = new FieldNameLookup ();
  40                         this.fieldCount = reader.FieldCount;
  41                         LoadSchema (reader.GetSchemaTable ());
  42                 }
  43
  44                 #endregion // Constructors
  45
  46                 #region Properties
  47
  48                 public object Current {
  49                         get {
  50                                 object[] values = new object[fieldCount];
  51                                 reader.GetValues (values);
  52                                 return new DbDataRecord (schema, values, lookup);
  53                         }
  54                 }
  55
  56                 #endregion // Properties
  57
  58                 #region Methods
  59
  60                 private void LoadSchema (DataTable schemaTable)
  61                 {
  62                         schema = new SchemaInfo [fieldCount];
  63                         int index = 0;
  64                         foreach (DataRow row in schemaTable.Rows) {
  65                                 SchemaInfo columnSchema = new SchemaInfo ();
  66
  67                                 lookup.Add ((string) row["ColumnName"]);
  68
  69                                 columnSchema.AllowDBNull = (bool) row ["AllowDBNull"];
  70                                 columnSchema.ColumnName = row ["ColumnName"].ToString ();
  71                                 columnSchema.ColumnOrdinal = (int) row ["ColumnOrdinal"];
  72                                 columnSchema.ColumnSize = (int) row ["ColumnSize"];
  73                                 columnSchema.DataTypeName = reader.GetDataTypeName (index);
  74                                 columnSchema.FieldType = reader.GetFieldType (index);
  75                                 columnSchema.IsReadOnly = (bool) row ["IsReadOnly"];
  76                                 columnSchema.TableName = row ["BaseTableName"].ToString ();
  77
  78                                 if (row ["NumericPrecision"] != DBNull.Value)
  79                                         columnSchema.NumericPrecision = (byte) row ["NumericPrecision"];
  80                                 else
  81                                         columnSchema.NumericPrecision = (byte) 0;
  82
  83                                 if (row ["NumericScale"] != DBNull.Value)
  84                                         columnSchema.NumericScale = (byte) row ["NumericScale"];
  85                                 else
  86                                         columnSchema.NumericScale = (byte) 0;
  87
  88                                 schema [index] = columnSchema;
  89                                 index += 1;
  90                         }
  91                 }
  92
  93                 public bool MoveNext ()
  94                 {
  95                         if (reader.Read ())
  96                                 return true;
  97                         if (closeReader)
  98                                 reader.Close ();
  99                         return false;
 100                 }
 101
 102                 [EditorBrowsable (EditorBrowsableState.Never)]
 103                 public void Reset ()
 104                 {
 105                         throw new NotSupportedException ();
 106                 }
 107
 108                 #endregion // Methods
 109         }
 110 }