Mercurial > pub > bltoolkit

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

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Копия текущей версии из github
author cin
date Thu, 27 Mar 2014 21:46:09 +0400
parents
children
comparison
equal deleted inserted replaced
-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 ScalarSelectBuilder : ISequenceBuilder
10 {
11 public int BuildCounter { get; set; }
12
13 public bool CanBuild(ExpressionBuilder builder, BuildInfo buildInfo)
14 {
15 return
16 buildInfo.Expression.NodeType == ExpressionType.Lambda &&
17 ((LambdaExpression)buildInfo.Expression).Parameters.Count == 0;
18 }
19
20 public IBuildContext BuildSequence(ExpressionBuilder builder, BuildInfo buildInfo)
21 {
22 return new ScalarSelectContext(builder)
23 {
24 Parent = buildInfo.Parent,
25 Expression = buildInfo.Expression,
26 SqlQuery = buildInfo.SqlQuery
27 };
28 }
29
30 public SequenceConvertInfo Convert(ExpressionBuilder builder, BuildInfo buildInfo, ParameterExpression param)
31 {
32 return null;
33 }
34
35 public bool IsSequence(ExpressionBuilder builder, BuildInfo buildInfo)
36 {
37 return true;
38 }
39
40 class ScalarSelectContext : IBuildContext
41 {
42 public ScalarSelectContext(ExpressionBuilder builder)
43 {
44 Builder = builder;
45
46 builder.Contexts.Add(this);
47 }
48
49 #if DEBUG
50 public string _sqlQueryText { get { return SqlQuery == null ? "" : SqlQuery.SqlText; } }
51 #endif
52
53 public ExpressionBuilder Builder { get; set; }
54 public Expression Expression { get; set; }
55 public SqlQuery SqlQuery { get; set; }
56 public IBuildContext Parent { get; set; }
57
58 public void BuildQuery<T>(Query<T> query, ParameterExpression queryParameter)
59 {
60 var expr = BuildExpression(null, 0);
61 var mapper = Builder.BuildMapper<T>(expr);
62
63 query.SetQuery(mapper.Compile());
64 }
65
66 public Expression BuildExpression(Expression expression, int level)
67 {
68 if (expression == null)
69 expression = ((LambdaExpression)Expression).Body.Unwrap();
70
71 switch (expression.NodeType)
72 {
73 case ExpressionType.New:
74 case ExpressionType.MemberInit:
75 {
76 var expr = Builder.BuildExpression(this, expression);
77
78 if (SqlQuery.Select.Columns.Count == 0)
79 SqlQuery.Select.Expr(new SqlValue(1));
80
81 return expr;
82 }
83
84 default :
85 {
86 var expr = Builder.ConvertToSql(this, expression, false);
87 var idx = SqlQuery.Select.Add(expr);
88
89 return Builder.BuildSql(expression.Type, idx);
90 }
91 }
92
93 }
94
95 public SqlInfo[] ConvertToSql(Expression expression, int level, ConvertFlags flags)
96 {
97 throw new NotImplementedException();
98 }
99
100 public SqlInfo[] ConvertToIndex(Expression expression, int level, ConvertFlags flags)
101 {
102 throw new NotImplementedException();
103 }
104
105 public IsExpressionResult IsExpression(Expression expression, int level, RequestFor requestFlag)
106 {
107 switch (requestFlag)
108 {
109 case RequestFor.Expression : return IsExpressionResult.True;
110 default : return IsExpressionResult.False;
111 }
112 }
113
114 public IBuildContext GetContext(Expression expression, int level, BuildInfo buildInfo)
115 {
116 throw new NotImplementedException();
117 }
118
119 public int ConvertToParentIndex(int index, IBuildContext context)
120 {
121 throw new NotImplementedException();
122 }
123
124 public void SetAlias(string alias)
125 {
126 }
127
128 public ISqlExpression GetSubQuery(IBuildContext context)
129 {
130 return null;
131 }
132 }
133 }
134 }