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comparison Source/Data/Linq/Builder/IntersectBuilder.cs @ 0:f990fcb411a9

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Копия текущей версии из github
author cin
date Thu, 27 Mar 2014 21:46:09 +0400
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-1:000000000000 0:f990fcb411a9
1 using System;
2 using System.Linq.Expressions;
3
4 namespace BLToolkit.Data.Linq.Builder
5 {
6 using BLToolkit.Linq;
7 using Data.Sql;
8
9 class IntersectBuilder : MethodCallBuilder
10 {
11 protected override bool CanBuildMethodCall(ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo)
12 {
13 return methodCall.Arguments.Count == 2 && methodCall.IsQueryable("Except", "Intersect");
14 }
15
16 protected override IBuildContext BuildMethodCall(ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo)
17 {
18 var sequence = builder.BuildSequence(new BuildInfo(buildInfo, methodCall.Arguments[0]));
19 var query = builder.BuildSequence(new BuildInfo(buildInfo, methodCall.Arguments[1], new SqlQuery()));
20 var except = query.SqlQuery;
21
22 sequence = new SubQueryContext(sequence);
23
24 var sql = sequence.SqlQuery;
25
26 except.ParentSql = sql;
27
28 if (methodCall.Method.Name == "Except")
29 sql.Where.Not.Exists(except);
30 else
31 sql.Where.Exists(except);
32
33 var keys1 = sequence.ConvertToSql(null, 0, ConvertFlags.Key);
34 var keys2 = query. ConvertToSql(null, 0, ConvertFlags.Key);
35
36 if (keys1.Length != keys2.Length)
37 throw new InvalidOperationException();
38
39 for (var i = 0; i < keys1.Length; i++)
40 {
41 except.Where
42 .Expr(keys1[i].Sql)
43 .Equal
44 .Expr(keys2[i].Sql);
45 }
46
47 return sequence;
48 }
49
50 protected override SequenceConvertInfo Convert(
51 ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo, ParameterExpression param)
52 {
53 return null;
54 }
55 }
56 }