SQL optimize the interview..-CodePudding

How the SQL optimization, and the date condition in the end, don't want to write two conditions,

 select a.A Level, count (1) HyCount, Max (p.n um) as Vnum 
The from _tmp_work a 
Left the join (select count (DISTINCT videoName) as num, ALevel from _tmp_work 
Where date> And date<='2020-7-1 00:00:00'; 23:59:59='2020-7-2' 
Group by alevel 
) p on a.A Level=p.A Level 
Where a. d. ate> 00:00:00='2020-7-1' and a. d. ate<23:59:59='2020-7-2' 
Group by a.A Level

CodePudding user response:

I feel you are the zha left the join is superfluous,
The select a.A Level, count (1) HyCount, count (DISTINCT videoName) as Vnum
The from _tmp_work a
Where a. d. ate> 00:00:00='2020-7-1' and a. d. ate<23:59:59='2020-7-2'
Group by a.A Level