动态构建linq查询 [英] build linq queries dynamically

问题描述

假设我有一个字符串列表，例如

suppose I have a string list, like

list<string> cols = {"id", "name", "position"}.

此列表是动态生成的，此列表中的每个代表数据库表中的列名.

This list is generated dynamically, and each one in this list represents a column name in a database table.

我要做的是动态创建一个linq查询，该查询仅返回这些列.

what I want to do is create a linq query dynamically which returns these columns only.

var q = from e in employ
        select new {
          id = id,
          name = name,
          position = position
};

如何根据输入列列表生成类似的查询?

How can I generate a query like that based on the input column lists?

推荐答案

您可以使用表达式树来构建动态Linq查询. 这是一个示例: http://msdn.microsoft.com/zh-cn/library/bb882637.aspx

You can use Expression Trees to build dynamic Linq queries. Here is an example: http://msdn.microsoft.com/en-us/library/bb882637.aspx

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