创建使用IQueryable的动态查询 [英] Creating a dynamic query using IQueryable

问题描述

我想通过一个字符串数组迭代并动态创建的IQueryable查询。它非常简单，但这里的地方我又立刻陷入

I'm trying to iterate for over an string array and dynamically create a Iqueryable query. Its pretty straightforward but here's where i'm stuck

var query = context.QuestionsMetaDatas.AsQueryable();

var keywords=new List<string>(){ "Test1","Test2" };

foreach(var key in keywords)
{
   query=query.Where(a=>a.Text.Contains(key));
}

现在的问题是，当查询获取生成其编译为
从QuestionsMetaDatas选择*，其中文字就像测试1和文字像'Test2的

Now the problem is that when the query gets generated its compiles to select * from QuestionsMetaDatas where Text Like 'Test1' AND Text Like 'Test2'

而不是，我想查询生成或...现在我怎样才能做到这一点？

Instead of "AND" i wanted the query to generate "OR"...Now how can i achieve this?

推荐答案

我用谓词建设者像拉斐尔认为，这只是一个文件在您的项目包括，那么你的例子就变成：

I have used predicate builder like Raphael suggested, it's just one file to include in your project, then your example becomes:

var keywords=new List<string>(){ "Test1","Test2" };

var predicate = PredicateBuilder.False<QuestionsMetaDatas>();

foreach (var key in keywords)
{
  predicate = predicate.Or (a => a.Text.Contains (key));
}

var query = context.QuestionsMetaDatas.AsQueryable().Where(predicate);

生成或查询您所期待的。

Generating the OR query your are looking for.

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