一个问题的问题SQL: IF clause within WHERE clause
让我们说:DeptID是传递给SQL Querry的参数,如果@DeptID为null,则显示全部,否则用DeptID过滤结果。
类似于某些伪代码
SELECT * FROM EMPLOYEE
IF :DeptID not = null
WHERE DeptID = :DeptID
ELSE (no filter)
Looking for correct syntax suitable for Poastgress & MySQL
SELECT *
FROM EMPLOYEE
WHERE :DeptID is null
OR :DeptID = DeptID