MySQL，显示行和列之间的具体值

Question

我有一个TABLE_1:

emp_id | salary_step | salary_level
1 | 13 | 4

现在，这是 TABLE_2:我想查询并获取以蓝色突出显示的值。我怎样才能做到这一点？多谢! (salary_grade 和 (1-8))

看图: TABLE_2

Answer 1

试试这个:

SELECT
    t1.*,
    CASE salary_level
        WHEN 1 THEN t2.`1`
        WHEN 2 THEN t2.`2`
        WHEN 3 THEN t2.`3`
        WHEN 4 THEN t2.`4`
    END AS LevelSalary
FROM TABLE_1 t1 INNER JOIN TABLE_2 t2 ON t1.salary_step = t2.salary_grade