sql常用语法合集

select sum (case when isintroduce = '0' then 1 else 0 end) noreg,sum (case when isintroduce ='1' then 1 else 0 end )reg from lae05 where 1=1

select count(1) as total ,
    sun(case when status ='end' then 1 else 0 ) as finish
from 
    fault where date_format(create_time,'%Y-%m-%d') >='2020-10-01' 
    and  date_format(create_time,'%Y-%m-%d') < '2020-12-12'

select 
   *,round((a.finish/a.total),2)*100 as percent
from (
    select 
        count(1) as total,
        sum(case when status =1 then 1 else 0) as finish 
    from fault where sorce between 12 and 50
) as a

select 
    name,age,course
from job group by course order b by userid

-- 单独一张表求和
select sum(case when status ='end') as end ,count(1) as total from fault;
select sum(case when status ='end') as end ,count(1) as total from repair;
-- 两张表结果求和并计算百分比
select sum(a.end) end,sum(a.total) total,round((end/total),2) as percent from (
select sum(case when status ='end' then 1 else 0 end) end,count(1) as total from fault
union all 
select sum(case when status ='end' then 1 else 0 end) end,count(1) as total from repair)a

SELECT
	*, round((b. END / b.total), 2) * 100 AS percentage
FROM
	(
		SELECT
			date_format(a.create_date, '%m-%d') AS date,
			sum(
				CASE
				WHEN a. STATUS = 'end' THEN
					1
				ELSE
					0
				END
			) AS
		END,
		count(1) AS total,
		processing_person_id AS processId
	FROM
		(
			SELECT
				create_date,
				STATUS,
				process_id,
				processing_person_id
			FROM
				fault
			UNION ALL
				SELECT
					create_date,
					STATUS,
					process_id,
					processing_person_id
				FROM
					REPAIR
		) a
	WHERE
		date_format(a.create_date, '%Y-%m-%d') >= '2020-03-01'
	AND date_format(a.create_date, '%Y-%m-%d') >= '2020-03-01'
	GROUP BY
		processing_person_id
	ORDER BY
		processing_person_id
	) b

-- 结果如下所示
date | end| total| percentage
--------------------------
03-22	7	12		58.00
--------------------------
04-09	0	3	3	0.00
--------------------------
04-09	0	1	4	0.00
--------------------------
03-05	0	6	18	0.00
--------------------------
04-01	0	2	22	0.00
--------------------------

-- 将整型类型转换成字符串
select cast(9, as CHAR);
-- 将字符串转换成时间格式 
selec case(NOW() as DATE);

-- 计算小明的所有成绩及格率  
select *,concat(cast(round((a.pass/a.count),2) as CHAR),'%') as percentag from (
select 
	count(1) as count,
	sum(case when grade > 60 then 1 else 0 end) as pass	
from result) a

select 
	a1.count sw,
	a2.count org,
	a3.count project  
from (
	SELECT 
		count(*) 
	from 
		lap21
	where 
		areaid >= 'areaid' and 
		areaid < 'maxAreaid') a1,
	(
	select 
		count(*) 
	from 
		lae01 
	where 
		areaid >= ' areaid ' and 
		areaid < ' maxAreaid ') a2,
	(
	SELECT 
		count(1) 
	from 
		lax03 
	where 
		areaid >= ' areaid ' and 
		areaid < 'maxAreaid ') a3;