示例#1
0
        protected override IBuildContext BuildMethodCall(ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo)
        {
            var sequence = builder.BuildSequence(new BuildInfo(buildInfo, methodCall.Arguments[0]));

            if (sequence.SelectQuery.Select.TakeValue != null ||
                sequence.SelectQuery.Select.SkipValue != null ||
                sequence.SelectQuery.Select.IsDistinct && !builder.DataContextInfo.SqlProviderFlags.IsDistinctOrderBySupported)
            {
                sequence = new SubQueryContext(sequence);
            }

            var lambda  = (LambdaExpression)methodCall.Arguments[1].Unwrap();
            var sparent = sequence.Parent;
            var order   = new ExpressionContext(buildInfo.Parent, sequence, lambda);
            var body    = lambda.Body.Unwrap();
            var sql     = builder.ConvertExpressions(order, body, ConvertFlags.Key);

            builder.ReplaceParent(order, sparent);

            if (!methodCall.Method.Name.StartsWith("Then"))
            {
                sequence.SelectQuery.OrderBy.Items.Clear();
            }

            foreach (var expr in sql)
            {
                var e = builder.ConvertSearchCondition(sequence, expr.Sql);
                sequence.SelectQuery.OrderBy.Expr(e, methodCall.Method.Name.EndsWith("Descending"));
            }

            return(sequence);
        }