使用SQL LIKE运算符的LINQ to Entities [英] LINQ to Entities using the SQL LIKE operator

问题描述

我有这个:

query = query.Where(s => s.ShowTypeDescription == showTypeDescription);

多次不同的变量以构建动态SQL.

several times for different variables in order to build dynamic SQL.

我该如何改变上面的说法:

How would I go about transforming the above to say:

query = query.Where(s => s.ShowTypeDescription **LIKE** showTypeDescription);

?

推荐答案

如果只想在另一个字符串中找到一个子字符串，最好的方法是使用Contains方法:

If all you want is to find a substring within another string, the best way to do this is with the Contains method:

query = query.Where(s => s.ShowTypeDescription.Contains(showTypeDescription));

因为String.Contains方法转换为:

CHARINDEX(ShowTypeDescription, @showTypeDescription) > 0

大致相当于:

ShowTypeDescription LIKE '%' + @showTypeDescription + '%'

更新:在Linq-to-SQL中，您可以使用

Update: In Linq-to-SQL, you can use the SqlMethods.Like method:

query = query.Where(s => SqlMethods.Like(s.ShowTypeDescription, showTypeDescription));

这将直接转换为SQL LIKE运算符.但是请注意，这在Linq-to-SQL查询之外不起作用.尝试在其他上下文中调用此方法将引发异常.

This will directly translate to the SQL LIKE operator. Note, however, this won't work outside of Linq-to-SQL queries. Trying to call this method in other contexts will throw an exception.

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