mcs/class/System.Data/System.Data/RelatedDataView.cs

   1 //\r
   2 // System.Data.RelatedDataView\r
   3 //\r
   4 // Author:\r
   5 //   Konstantin Triger (kostat@mainsoft.com)\r
   6 //\r
   7 \r
   8 using System;\r
   9 using System.Collections;\r
  10 using Mono.Data.SqlExpressions;\r
  11 using System.Data.Common;\r
  12 \r
  13 namespace System.Data\r
  14 {\r
  15         /// <summary>\r
  16         /// Summary description for RelatedDataView.\r
  17         /// </summary>\r
  18         internal class RelatedDataView : DataView, IExpression\r
  19         {\r
  20                 #region Fields\r
  21                 \r
  22                 object[] _keyValues;\r
  23                 DataColumn[] _columns;\r
  24 \r
  25                 #endregion // Fields\r
  26 \r
  27                 #region Constructors\r
  28                 internal RelatedDataView(DataColumn[] relatedColumns,object[] keyValues)\r
  29                 {\r
  30                         dataTable = relatedColumns[0].Table;\r
  31                         _columns = relatedColumns;\r
  32                         _keyValues = keyValues;\r
  33 \r
  34                         UpdateIndex(true);\r
  35                 }\r
  36 \r
  37                 #endregion // Constructors\r
  38 \r
  39                 #region Methods\r
  40 \r
  41                 internal override IExpression FilterExpression {\r
  42                         get {\r
  43                                 return this;\r
  44                         }\r
  45                 }\r
  46 \r
  47 \r
  48                 #endregion // Methods\r
  49 \r
  50                 #region IExpression Members\r
  51 \r
  52                 public object Eval(DataRow row) {\r
  53                         return EvalBoolean(row);\r
  54                 }\r
  55 \r
  56                 public bool EvalBoolean(DataRow row) {\r
  57                         for (int i = 0; i < _columns.Length; i++)\r
  58                                 if (!row[_columns[i]].Equals(_keyValues[i]))\r
  59                                         return false;\r
  60 \r
  61                         IExpression filter = base.FilterExpression;\r
  62                         return filter != null ? filter.EvalBoolean(row) : true;\r
  63                 }\r
  64 \r
  65                 public bool DependsOn(DataColumn other) {\r
  66                         for (int i = 0; i < _columns.Length; i++)\r
  67                                 if (_columns[i] == other)\r
  68                                         return true;\r
  69 \r
  70                         IExpression filter = base.FilterExpression;\r
  71                         return filter != null ? filter.DependsOn(other) : false;\r
  72                 }\r
  73 \r
  74                 #endregion\r
  75         }\r
  76 }\r