用于Where子句或join中聚合函数的Linq2sql

以下SQL语句对应的linq2sql语句是什么

SELECT id, userName
FROM users
WHERE
  (SELECT COUNT(*) FROM logins WHERE logins.userId=users.id) > 0

或写为连接：

SELECT id, userName
FROM users 
LEFT JOIN logins ON logins.id=(SELECT MIN(id) FROM logins WHERE userId=users.id)
WHERE logins.id IS NOT NULL

thx

假设您的上下文中有“user”和“login”数据库集，并且上下文的名称为“context”：

var result = from user in context.users
             where (from  login in context.logins
                     where login.userId = user.userId
                     select login).Count() > 0
             select user.Id,userName