MySQL case when条件分支判断

举例说明

SELECT
    CASE a.AFTER_QUALITY
WHEN ‘0‘ THEN
    ‘过免维期‘
WHEN ‘1‘ THEN
    ‘未过免维期‘
ELSE
    ‘错误数据‘
END AS AFTER_QUALITY
FROM
    t_maintain_log a

数据库表内容：

运行结果：