Mercurial > pub > bltoolkit
view Source/Data/Linq/Builder/ContainsBuilder.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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using System; using System.Linq.Expressions; namespace BLToolkit.Data.Linq.Builder { using BLToolkit.Linq; using Data.Sql; class ContainsBuilder : MethodCallBuilder { protected override bool CanBuildMethodCall(ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo) { return methodCall.IsQueryable("Contains") && methodCall.Arguments.Count == 2; } protected override IBuildContext BuildMethodCall(ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo) { var sequence = builder.BuildSequence(new BuildInfo(buildInfo, methodCall.Arguments[0])); return new ContainsContext(buildInfo.Parent, methodCall, sequence); } protected override SequenceConvertInfo Convert( ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo, ParameterExpression param) { return null; } class ContainsContext : SequenceContextBase { readonly MethodCallExpression _methodCall; public ContainsContext(IBuildContext parent, MethodCallExpression methodCall, IBuildContext sequence) : base(parent, sequence, null) { _methodCall = methodCall; } public override void BuildQuery<T>(Query<T> query, ParameterExpression queryParameter) { var sql = GetSubQuery(null); query.Queries[0].SqlQuery = new SqlQuery(); query.Queries[0].SqlQuery.Select.Add(sql); var expr = Builder.BuildSql(typeof(bool), 0); var mapper = Builder.BuildMapper<object>(expr); query.SetElementQuery(mapper.Compile()); } public override Expression BuildExpression(Expression expression, int level) { var idx = ConvertToIndex(expression, level, ConvertFlags.Field); return Builder.BuildSql(typeof(bool), idx[0].Index); } public override SqlInfo[] ConvertToSql(Expression expression, int level, ConvertFlags flags) { if (expression == null) { var sql = GetSubQuery(null); var query = SqlQuery; if (Parent != null) query = Parent.SqlQuery; return new[] { new SqlInfo { Query = query, Sql = sql } }; } throw new InvalidOperationException(); } public override SqlInfo[] ConvertToIndex(Expression expression, int level, ConvertFlags flags) { var sql = ConvertToSql(expression, level, flags); if (sql[0].Index < 0) sql[0].Index = sql[0].Query.Select.Add(sql[0].Sql); return sql; } public override IsExpressionResult IsExpression(Expression expression, int level, RequestFor requestFlag) { if (expression == null) { switch (requestFlag) { case RequestFor.Expression : case RequestFor.Field : return IsExpressionResult.False; } } throw new InvalidOperationException(); } public override IBuildContext GetContext(Expression expression, int level, BuildInfo buildInfo) { throw new InvalidOperationException(); } ISqlExpression _subQuerySql; public override ISqlExpression GetSubQuery(IBuildContext context) { if (_subQuerySql == null) { var args = _methodCall.Method.GetGenericArguments(); var param = Expression.Parameter(args[0], "param"); var expr = _methodCall.Arguments[1]; var condition = Expression.Lambda(Expression.Equal(param, expr), param); IBuildContext ctx = new ExpressionContext(Parent, Sequence, condition); ctx = Builder.GetContext(ctx, expr) ?? ctx; Builder.ReplaceParent(ctx, this); SqlQuery.Condition cond; if (Sequence.SqlQuery != SqlQuery && (ctx.IsExpression(expr, 0, RequestFor.Field). Result || ctx.IsExpression(expr, 0, RequestFor.Expression).Result)) { Sequence.ConvertToIndex(null, 0, ConvertFlags.All); var ex = Builder.ConvertToSql(ctx, _methodCall.Arguments[1], false); cond = new SqlQuery.Condition(false, new SqlQuery.Predicate.InSubQuery(ex, false, SqlQuery)); } else { var sequence = Builder.BuildWhere(Parent, Sequence, condition, true); cond = new SqlQuery.Condition(false, new SqlQuery.Predicate.FuncLike(SqlFunction.CreateExists(sequence.SqlQuery))); } _subQuerySql = new SqlQuery.SearchCondition(cond); } return _subQuerySql; } } } }