实体框架上的多个 .Where() 子句可查询

Multiple .Where() clauses on an Entity Framework Queryable(实体框架上的多个 .Where() 子句可查询)

问题描述

我正在尝试使用实体框架实现一个复杂的过滤器:我想根据我提供的搜索条件将 where 子句添加到可查询对象.

I am trying to implement a complex filter using Entity Framework: I want to add where clauses to the queryable object based on my provided search criteria.

我可以在 Entity Framework 6 中执行以下操作吗?

Can I do the following in Entity Framework 6?

var queryable = db.Users.Where(x => x.Enabled && !x.Deleted);
// Filter
var userId = User.Identity.GetUserId();
queryable.Where(x => x.AspNetUser.Id == userId);
queryable.Where(x => x.Status >= 2); 
// ...etc

我知道我能做到:

var queryable = db.Users
 .Where(x => x.Enabled && !x.Deleted)
 .Where(x => x.AspNetUser.Id == userId)
 .Where(x => x.Status >= 2); 

但是我没有通过这个解决方案获得预期的结果.它似乎忽略了秒两个 where 子句.

But I am not getting the expected results with this solution. It seems to be ignoring the seconds two where clauses.

推荐答案

.Where 返回一个可查询的，它不修改原来的.所以你只需要保存新的可查询对象.

.Where returns a queryable, it does not modify the original. So you just need to save the new queryable.

var queryable = db.Users.Where(x => x.Enabled && !x.Deleted);
// Filter
var userId = User.Identity.GetUserId();
queryable = queryable.Where(x => x.AspNetUser.Id == userId);
queryable = queryable.Where(x => x.Status >= 2); 
// ...etc

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