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comparison Source/Data/Linq/Builder/JoinBuilder.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.Collections.Generic;
3 using System.Linq;
4 using System.Linq.Expressions;
5
6 namespace BLToolkit.Data.Linq.Builder
7 {
8 using BLToolkit.Linq;
9 using Data.Sql;
10
11 class JoinBuilder : MethodCallBuilder
12 {
13 protected override bool CanBuildMethodCall(ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo)
14 {
15 if (!methodCall.IsQueryable("Join", "GroupJoin") || methodCall.Arguments.Count != 5)
16 return false;
17
18 var body = ((LambdaExpression)methodCall.Arguments[2].Unwrap()).Body.Unwrap();
19
20 if (body.NodeType == ExpressionType .MemberInit)
21 {
22 var mi = (MemberInitExpression)body;
23 bool throwExpr;
24
25 if (mi.NewExpression.Arguments.Count > 0 || mi.Bindings.Count == 0)
26 throwExpr = true;
27 else
28 throwExpr = mi.Bindings.Any(b => b.BindingType != MemberBindingType.Assignment);
29
30 if (throwExpr)
31 throw new NotSupportedException(string.Format("Explicit construction of entity type '{0}' in join is not allowed.", body.Type));
32 }
33
34 return true;
35 }
36
37 protected override IBuildContext BuildMethodCall(ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo)
38 {
39 var isGroup = methodCall.Method.Name == "GroupJoin";
40 var outerContext = builder.BuildSequence(new BuildInfo(buildInfo, methodCall.Arguments[0], buildInfo.SqlQuery));
41 var innerContext = builder.BuildSequence(new BuildInfo(buildInfo, methodCall.Arguments[1], new SqlQuery()));
42 var countContext = builder.BuildSequence(new BuildInfo(buildInfo, methodCall.Arguments[1], new SqlQuery()));
43
44 var context = new SubQueryContext(outerContext);
45 innerContext = isGroup ? new GroupJoinSubQueryContext(innerContext, methodCall) : new SubQueryContext(innerContext);
46 countContext = new SubQueryContext(countContext);
47
48 var join = isGroup ? innerContext.SqlQuery.WeakLeftJoin() : innerContext.SqlQuery.InnerJoin();
49 var sql = context.SqlQuery;
50
51 sql.From.Tables[0].Joins.Add(join.JoinedTable);
52
53 var selector = (LambdaExpression)methodCall.Arguments[4].Unwrap();
54
55 context.SetAlias(selector.Parameters[0].Name);
56 innerContext.SetAlias(selector.Parameters[1].Name);
57
58 var outerKeyLambda = ((LambdaExpression)methodCall.Arguments[2].Unwrap());
59 var innerKeyLambda = ((LambdaExpression)methodCall.Arguments[3].Unwrap());
60
61 var outerKeySelector = outerKeyLambda.Body.Unwrap();
62 var innerKeySelector = innerKeyLambda.Body.Unwrap();
63
64 var outerParent = context. Parent;
65 var innerParent = innerContext.Parent;
66 var countParent = countContext.Parent;
67
68 var outerKeyContext = new ExpressionContext(buildInfo.Parent, context, outerKeyLambda);
69 var innerKeyContext = new InnerKeyContext (buildInfo.Parent, innerContext, innerKeyLambda);
70 var countKeyContext = new ExpressionContext(buildInfo.Parent, countContext, innerKeyLambda);
71
72 // Process counter.
73 //
74 var counterSql = ((SubQueryContext)countContext).SqlQuery;
75
76 // Make join and where for the counter.
77 //
78 if (outerKeySelector.NodeType == ExpressionType.New)
79 {
80 var new1 = (NewExpression)outerKeySelector;
81 var new2 = (NewExpression)innerKeySelector;
82
83 for (var i = 0; i < new1.Arguments.Count; i++)
84 {
85 var arg1 = new1.Arguments[i];
86 var arg2 = new2.Arguments[i];
87
88 BuildJoin(builder, join, outerKeyContext, arg1, innerKeyContext, arg2, countKeyContext, counterSql);
89 }
90 }
91 else if (outerKeySelector.NodeType == ExpressionType.MemberInit)
92 {
93 var mi1 = (MemberInitExpression)outerKeySelector;
94 var mi2 = (MemberInitExpression)innerKeySelector;
95
96 for (var i = 0; i < mi1.Bindings.Count; i++)
97 {
98 if (mi1.Bindings[i].Member != mi2.Bindings[i].Member)
99 throw new LinqException(string.Format("List of member inits does not match for entity type '{0}'.", outerKeySelector.Type));
100
101 var arg1 = ((MemberAssignment)mi1.Bindings[i]).Expression;
102 var arg2 = ((MemberAssignment)mi2.Bindings[i]).Expression;
103
104 BuildJoin(builder, join, outerKeyContext, arg1, innerKeyContext, arg2, countKeyContext, counterSql);
105 }
106 }
107 else
108 {
109 BuildJoin(builder, join, outerKeyContext, outerKeySelector, innerKeyContext, innerKeySelector, countKeyContext, counterSql);
110 }
111
112 builder.ReplaceParent(outerKeyContext, outerParent);
113 builder.ReplaceParent(innerKeyContext, innerParent);
114 builder.ReplaceParent(countKeyContext, countParent);
115
116 if (isGroup)
117 {
118 counterSql.ParentSql = sql;
119 counterSql.Select.Columns.Clear();
120
121 var inner = (GroupJoinSubQueryContext)innerContext;
122
123 inner.Join = join.JoinedTable;
124 inner.CounterSql = counterSql;
125 return new GroupJoinContext(
126 buildInfo.Parent, selector, context, inner, methodCall.Arguments[1], outerKeyLambda, innerKeyLambda);
127 }
128
129 return new JoinContext(buildInfo.Parent, selector, context, innerContext)
130 #if DEBUG
131 {
132 MethodCall = methodCall
133 }
134 #endif
135 ;
136 }
137
138 protected override SequenceConvertInfo Convert(
139 ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo, ParameterExpression param)
140 {
141 return null;
142 }
143
144 static void BuildJoin(
145 ExpressionBuilder builder,
146 SqlQuery.FromClause.Join join,
147 IBuildContext outerKeyContext, Expression outerKeySelector,
148 IBuildContext innerKeyContext, Expression innerKeySelector,
149 IBuildContext countKeyContext, SqlQuery countSql)
150 {
151 var predicate = builder.ConvertObjectComparison(
152 ExpressionType.Equal,
153 outerKeyContext, outerKeySelector,
154 innerKeyContext, innerKeySelector);
155
156 if (predicate != null)
157 join.JoinedTable.Condition.Conditions.Add(new SqlQuery.Condition(false, predicate));
158 else
159 join
160 .Expr(builder.ConvertToSql(outerKeyContext, outerKeySelector, false)).Equal
161 .Expr(builder.ConvertToSql(innerKeyContext, innerKeySelector, false));
162
163 predicate = builder.ConvertObjectComparison(
164 ExpressionType.Equal,
165 outerKeyContext, outerKeySelector,
166 countKeyContext, innerKeySelector);
167
168 if (predicate != null)
169 countSql.Where.SearchCondition.Conditions.Add(new SqlQuery.Condition(false, predicate));
170 else
171 countSql.Where
172 .Expr(builder.ConvertToSql(outerKeyContext, outerKeySelector, false)).Equal
173 .Expr(builder.ConvertToSql(countKeyContext, innerKeySelector, false));
174 }
175
176 class InnerKeyContext : ExpressionContext
177 {
178 public InnerKeyContext(IBuildContext parent, IBuildContext sequence, LambdaExpression lambda)
179 : base(parent, sequence, lambda)
180 {
181 }
182
183 public override SqlInfo[] ConvertToSql(Expression expression, int level, ConvertFlags flags)
184 {
185 return base
186 .ConvertToSql(expression, level, flags)
187 .Select(idx =>
188 {
189 var n = SqlQuery.Select.Add(idx.Sql);
190
191 return new SqlInfo(idx.Members)
192 {
193 Sql = SqlQuery.Select.Columns[n],
194 Index = n
195 };
196 })
197 .ToArray();
198 }
199 }
200
201 internal class JoinContext : SelectContext
202 {
203 public JoinContext(IBuildContext parent, LambdaExpression lambda, IBuildContext outerContext, IBuildContext innerContext)
204 : base(parent, lambda, outerContext, innerContext)
205 {
206 }
207 }
208
209 internal class GroupJoinContext : JoinContext
210 {
211 public GroupJoinContext(
212 IBuildContext parent,
213 LambdaExpression lambda,
214 IBuildContext outerContext,
215 GroupJoinSubQueryContext innerContext,
216 Expression innerExpression,
217 LambdaExpression outerKeyLambda,
218 LambdaExpression innerKeyLambda)
219 : base(parent, lambda, outerContext, innerContext)
220 {
221 _innerExpression = innerExpression;
222 _outerKeyLambda = outerKeyLambda;
223 _innerKeyLambda = innerKeyLambda;
224
225 innerContext.GroupJoin = this;
226 }
227
228 readonly Expression _innerExpression;
229 readonly LambdaExpression _outerKeyLambda;
230 readonly LambdaExpression _innerKeyLambda;
231 private Expression _groupExpression;
232
233 interface IGroupJoinHelper
234 {
235 Expression GetGroupJoin(GroupJoinContext context);
236 }
237
238 class GroupJoinHelper<TKey,TElement> : IGroupJoinHelper
239 {
240 public Expression GetGroupJoin(GroupJoinContext context)
241 {
242 // Convert outer condition.
243 //
244 var outerParam = Expression.Parameter(context._outerKeyLambda.Body.Type, "o");
245 var outerKey = context._outerKeyLambda.Body.Convert(
246 e => e == context._outerKeyLambda.Parameters[0] ? context.Lambda.Parameters[0] : e);
247
248 outerKey = context.Builder.BuildExpression(context, outerKey);
249
250 // Convert inner condition.
251 //
252 var parameters = context.Builder.CurrentSqlParameters
253 .Select((p,i) => new { p, i })
254 .ToDictionary(_ => _.p.Expression, _ => _.i);
255 var paramArray = Expression.Parameter(typeof(object[]), "ps");
256
257 var innerKey = context._innerKeyLambda.Body.Convert(e =>
258 {
259 int idx;
260
261 if (parameters.TryGetValue(e, out idx))
262 {
263 return
264 Expression.Convert(
265 Expression.ArrayIndex(paramArray, Expression.Constant(idx)),
266 e.Type);
267 }
268
269 return e;
270 });
271
272 // Item reader.
273 //
274 // ReSharper disable AssignNullToNotNullAttribute
275
276 var expr = Expression.Call(
277 null,
278 ReflectionHelper.Expressor<object>.MethodExpressor(_ => Queryable.Where(null, (Expression<Func<TElement,bool>>)null)),
279 context._innerExpression,
280 Expression.Lambda<Func<TElement,bool>>(
281 Expression.Equal(innerKey, outerParam),
282 new[] { context._innerKeyLambda.Parameters[0] }));
283
284 // ReSharper restore AssignNullToNotNullAttribute
285
286 var lambda = Expression.Lambda<Func<IDataContext,TKey,object[],IQueryable<TElement>>>(
287 Expression.Convert(expr, typeof(IQueryable<TElement>)),
288 Expression.Parameter(typeof(IDataContext), "ctx"),
289 outerParam,
290 paramArray);
291
292 var itemReader = CompiledQuery.Compile(lambda);
293
294 return Expression.Call(
295 null,
296 ReflectionHelper.Expressor<object>.MethodExpressor(_ => GetGrouping(null, null, default(TKey), null)),
297 new[]
298 {
299 ExpressionBuilder.ContextParam,
300 Expression.Constant(context.Builder.CurrentSqlParameters),
301 outerKey,
302 Expression.Constant(itemReader),
303 });
304 }
305
306 static IEnumerable<TElement> GetGrouping(
307 QueryContext context,
308 List<ParameterAccessor> parameterAccessor,
309 TKey key,
310 Func<IDataContext,TKey,object[],IQueryable<TElement>> itemReader)
311 {
312 return new GroupByBuilder.GroupByContext.Grouping<TKey,TElement>(key, context, parameterAccessor, itemReader);
313 }
314 }
315
316 public override Expression BuildExpression(Expression expression, int level)
317 {
318 if (expression == Lambda.Parameters[1])
319 {
320 if (_groupExpression == null)
321 {
322 var gtype = typeof(GroupJoinHelper<,>).MakeGenericType(
323 _innerKeyLambda.Body.Type,
324 _innerKeyLambda.Parameters[0].Type);
325
326 var helper = (IGroupJoinHelper)Activator.CreateInstance(gtype);
327
328 _groupExpression = helper.GetGroupJoin(this);
329 }
330
331 return _groupExpression;
332 }
333
334 return base.BuildExpression(expression, level);
335 }
336 }
337
338 internal class GroupJoinSubQueryContext : SubQueryContext
339 {
340 //readonly MethodCallExpression _methodCall;
341
342 public SqlQuery.JoinedTable Join;
343 public SqlQuery CounterSql;
344 public GroupJoinContext GroupJoin;
345
346 public GroupJoinSubQueryContext(IBuildContext subQuery, MethodCallExpression methodCall)
347 : base(subQuery)
348 {
349 //_methodCall = methodCall;
350 }
351
352 public override IBuildContext GetContext(Expression expression, int level, BuildInfo buildInfo)
353 {
354 if (expression == null)
355 return this;
356
357 return base.GetContext(expression, level, buildInfo);
358 }
359
360 Expression _counterExpression;
361 SqlInfo[] _counterInfo;
362
363 public override SqlInfo[] ConvertToIndex(Expression expression, int level, ConvertFlags flags)
364 {
365 if (expression != null && expression == _counterExpression)
366 return _counterInfo ?? (_counterInfo = new[]
367 {
368 new SqlInfo
369 {
370 Query = CounterSql.ParentSql,
371 Index = CounterSql.ParentSql.Select.Add(CounterSql),
372 Sql = CounterSql
373 }
374 });
375
376 return base.ConvertToIndex(expression, level, flags);
377 }
378
379 public override IsExpressionResult IsExpression(Expression expression, int level, RequestFor testFlag)
380 {
381 if (testFlag == RequestFor.GroupJoin && expression == null)
382 return IsExpressionResult.True;
383
384 return base.IsExpression(expression, level, testFlag);
385 }
386
387 public SqlQuery GetCounter(Expression expr)
388 {
389 Join.IsWeak = true;
390
391 _counterExpression = expr;
392
393 return CounterSql;
394 }
395 }
396 }
397 }