Question

我在下面尝试：

--create temporary table
declare @tempemp TABLE(
  salary int
);

--get maximum salary of employees in sbi
insert into @tempemp
  select MAX(salary) as 'salary' from employee where company='sbi';

现在，我希望获得所有员工的姓名，这些员工的收入超过了所有sbi员工。我试过这个：

select * from employee where employee.salary > @tempemp.salary;

但是这给了我错误：

Must declare the scalar variable "@tempemp".

虽然这完全正常：

select * from @tempemp;

与前两个（声明和插入）查询一起执行。

Answer 1

不要使用表格，使用变量：

declare @salary int;

select @salary = MAX(salary)
from employee
where company = 'sbi';

select *
from employee
where employee.salary > @salary;

如果您使用表格，则需要一个子选择：

select *
from employee
where employee.salary > (select salary from @tempemp.salary);

我假设您有理由单独存储值，因为您可以这样做：

select *
from employee
where employee.salary > (select max(salary) from employee where company = 'sbi');

Answer 2

如果没有tablename alias子句，则不能将where用作selecting。你必须从表中选择。试试这个。

select * from employee 
where employee.salary > (select salary from @tempemp)

“必须在声明表的where子句内声明标量变量”

2 个答案: