Mercurial > pub > bltoolkit
diff Source/Data/Linq/Builder/DistinctBuilder.cs @ 0:f990fcb411a9
Копия текущей версии из github
author | cin |
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date | Thu, 27 Mar 2014 21:46:09 +0400 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Source/Data/Linq/Builder/DistinctBuilder.cs Thu Mar 27 21:46:09 2014 +0400 @@ -0,0 +1,35 @@ +using System; +using System.Linq.Expressions; + +namespace BLToolkit.Data.Linq.Builder +{ + using BLToolkit.Linq; + + class DistinctBuilder : MethodCallBuilder + { + protected override bool CanBuildMethodCall(ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo) + { + return methodCall.IsQueryable("Distinct"); + } + + protected override IBuildContext BuildMethodCall(ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo) + { + var sequence = builder.BuildSequence(new BuildInfo(buildInfo, methodCall.Arguments[0])); + var sql = sequence.SqlQuery; + + if (sql.Select.TakeValue != null || sql.Select.SkipValue != null) + sequence = new SubQueryContext(sequence); + + sequence.SqlQuery.Select.IsDistinct = true; + sequence.ConvertToIndex(null, 0, ConvertFlags.All); + + return sequence; + } + + protected override SequenceConvertInfo Convert( + ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo, ParameterExpression param) + { + return null; + } + } +}