查询sql join和where子句

Question

第一名员工

id   empName     empEmail           empSal   active
====================================================
13   sadf        asdf@sdf.com       233       1
12   checkout    cherckout@g.com    3         1
11   safg        asdf@asdf.com      123       1
10   sdf         sadf@sdf           4         1
9    sdaf        asdf@sdf.com       3         1
8    asdf        asdf@sdf.com       8         1
7    asdf        asdf@sdf.com       8         1
6    asdf        asdf@sdf.com       8         1

第二张表emp_status

id  emp_id  EmpSalary  active
=============================
5   4       156        1
4   2       156        1
3   2       555        1
2   1       200        0
1   1       1500       1



SELECT o.*
FROM employees as o
LEFT JOIN emp_status as emp ON emp.emp_id = o.id
WHERE (emp.active IS NULL OR (emp.active != 0))
GROUP BY o.id
ORDER BY o.id DESC

如果emp_status有两行，其中一行的状态为1，另一行的状态为0，我们想要它不应该计为1，如果我有零，它应该有助于执行。怎么可能呢？

Answer 1

不要在where子句上传递连接表条件，我建议你激活列数据类型= ENUM并设置值0,1,2,3,4,5,6

SELECT o.* FROM employees as o
LEFT JOIN emp_status as emp ON emp.emp_id = o.id and emp.active IN (1,2,3,5,6) GROUP BY o.id ORDER BY o.id DESC