MySql 将查到的数值（0，1，2）转换为相关的文字

1 基本查询

如下所示为常用查询示例，statues 状态为 0、1

SELECT
	tut.id,
	tut.statues
FROM
	t_user_train_study as tut
WHERE
	tut.train_id =72

2 转查询结果

SELECT
	tut.id,
	CASE
		WHEN tut.statues = 0 THEN
		'未完成' 
		WHEN tut.statues = 1 THEN
		'已完成' 
		WHEN tut.statues is null THEN
		'未完成' 
	END AS 状态 
FROM
	t_user_train_study as tut
WHERE
	tut.train_id =72