limit的用法与打标的用法丨记德勤真题

limit 1,1000是指显示第1个后面开始数1000个即2.3.4.5...1001

三千用户每人1000，应该是

limit 0,1000 这里是1-1000

limt 1000,1000 这里是1001-2000

limit 2000,1000 这里是2001-3000

with test_A as 
(
SELECT Phone_number
from User_info 
where Campaign_id = "Campaign_001"
group by Phone_number
order by Phone_number
)
SELECT Phone_number,"WEB"
from test_A
limit 0,1000
union 
SELECT Phone_number,"WECHAT"
from test_A
limit 1000,1000
UNION 
SELECT Phone_number,"APP"
from test_A
limit 2000,1000

打标的用法： 如select+'测试'就会加多一个字段叫测试，然后内容也是测试，这样就方便筛选

实际例子如我这个加了'前25%'的例子