我不知道这个查询

Question

I am a beginner at SQL. I am trying to write a query which "provides the Total salary drawn by all people for each department if the total salary is greater than 300,000". I have written some of it, but can't figure it out completely.

USE EMP_DB_01;
SELECT DEPTNAME, SUM(SALARY) AS 'Total Salary'
FROM DEPT, EMP 
WHERE (SALARY > 300000) AND (DEPT.DEPTNO = EMP.DEPTNO)
GROUP BY DEPTNAME

Table is here enter image description here

Answer 1

You should use a join between the DEPT and EMP could be based on DEPT.DEPTNO = EMP.DEPTNO ..and for total salary is greater than 300,000 you should use having and not where

Having filter the result of aggregated result .. where filter the rows values

this return the dept and the the related Total Salary when the sum is > 300.00

USE EMP_DB_01;
SELECT DEPTNAME, SUM(SALARY) AS 'Total Salary'
FROM DEPT
INNER JOIN  EMP ON DEPT.DEPTNO = EMP.DEPTNO
HAVING  SUM(SALARY) > 300000
GROUP BY DEPTNAME