使用PredicateBuilder，LINQPad和运算符ANY生成的SQL [英] Generated SQL with PredicateBuilder, LINQPad and operator ANY

问题描述

我先前提出的问题有关中链条件的问题Linq To实体. 现在，我使用 LinqKit ，一切正常. 我想查看生成的SQL，并在阅读此答案后，使用

I previously asked a question about chaining conditions in Linq To Entities. Now I use LinqKit and everything works fine. I want to see the generated SQL and after reading this answer, I use LinqPad.

这是我的声明:

var predProduct = PredicateBuilder.True<Product>();
var predColorLanguage = PredicateBuilder.True<ColorLanguage>();

predProduct = predProduct.And(p => p.IsComplete);

predColorLanguage = predColorLanguage.And(c => c.IdColorEntity.Products.AsQueryable().Any(expr));

ColorLanguages.Where(predColorLanguage).Dump();

该代码可在VS2008中运行，编译并生成正确的结果集，但在LinqPad中，出现以下错误:

The code works in VS2008, compile and produce the correct result set, but in LinqPad, I've the following error:

NotSupportedException: The overload query operator 'Any' used is not Supported.

如果LINQPad失败，如何查看生成的SQL?

How can I see the generated SQL if LINQPad fails?

编辑

如果我写

var predColorLanguage = PredicateBuilder.True<ColorLanguage>();

predColorLanguage = predColorLanguage.And(c => c.IdColorEntity.Products.Any((p => p.IsComplete));

ColorLanguages.Where(predColorLanguage).Dump();

有效... WTF吗?

works... WTF?

推荐答案

在使用LINQKit时，可以通过在提供EntitySet的表达式上调用Compile()，然后在LINQKit上调用AsExpandable()来完成此工作.主要查询:

As you're using LINQKit, you can make this work by calling Compile() on the expression that feeds the EntitySet, and then calling AsExpandable() on the main query:

var predProduct = PredicateBuilder.True<Product>();
var predColorLanguage = PredicateBuilder.True<ColorLanguage>();

predProduct = predProduct.And(p => p.IsComplete);

predColorLanguage = predColorLanguage.And (
  c => c.IdColorEntity.Products.Any(predProduct.Compile()));

ColorLanguages.AsExpandable().Where(predColorLanguage).Dump();

正如LINQKit文章中解释的 所述，Compile方法实际上从未运行:AsExpandable删除它并修改表达式树，以便它与LINQ to SQL一起使用.

As explained in the LINQKit article, the Compile method never actually runs: AsExpandable strips it out and modifies the expression tree so that it works with LINQ to SQL.

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