Question

我在linq中使用any时遇到问题，我不知道如何正确执行。我必须用linq编写：

SELECT ename, job, deptno
FROM emp
WHERE sal > ANY
(
    SELECT DISTINCT sal
    FROM emp
    WHERE deptno = 30
);

我只写这个：

var min = (from emp in Emps
           where emp.Deptno == 30
           select emp.Sal
          ).Distinct();

var result = (from emp in Emps
              where min.Any() > emp.Sal
              select new
              {
                  emp.Ename
              });

Answer 1

Linq没有像Sql Server一样的any/some运算符。

var salariesInTargetDepartment = Emps
    .Where(x => x.Deptno == 30)
    .Select(x => x.Sal)
    .Distinct()
    .ToList(); // the ToList is not required, but seeing you're going to be executing
               // against this query many times, it will be better to cache the results.

var matchingEmployees = Emps
    .Where(emp => salariesInTargetDepartment
        .Any(target => emp.Sal > target)
    );

第二条语句中的where子句说：“仅当该记录的Sal属性大于salariesInTargetDepartment集合中的至少一个条目时，才包括该记录。”

如何使用linq用任何量词编写子查询？

1 个答案: