MySql惯用(三、流程和其他)函数

MySql常用(三、流程和其他)函数


5.4流程函数

select id, if(is_check_in = '1', CONCAT(name, ':Need'), CONCAT(name, ':Not')) as CheckIn 
	FROM t_conf_visit_task 
		where is_delete = '0' and name is not null order by id asc limit 0, 5;

select id, ifnull(is_user, 0) as user 
	FROM t_conf_visit_task 
		where is_delete = '0' order by id asc limit 0,5;		

CASE
	WHEN expr1 
		THEN result1
	WHEN expr2
		THEN result2
	......
	ELSE [result]
END
当满足条件expr[1、2、3...]时，返回对应的result，否则返回ELSE后的result。

select plan_id, case
	when interval_type = '1'
		then '每日' 
	when interval_type = '2'
		then '每周' 
	when interval_type = '3'
		then '每月' 
	else '自定义'
	end as '目标时间间隔'
		from t_visit_plan
			where is_delete = '0' order by plan_id asc limit 0,5;

CASE expr 
	WHEN value1 
		THEN result1 
	WHEN value2
		THEN result2
	......
	ELSE [default] 
END 
当满足条件expr = value[1、2、3...]时，返回对应的result，否则返回ELSE后的result。 

select plan_id, 
       case interval_type 
		when '1' then '每日' 
		when '2' then '每周'
		when '3' then '每月'
                else '自定义'
	end as '目标时间间隔'
		from t_visit_plan
			where is_delete = '0' order by plan_id asc limit 0,5;

5.5其他常用函数