sql调优方法:
(1)not in子查询优化
尽量避免子查询select * from a where id not in(select id from b);
select * from a where not exists(select id from b WHERE id ='100')
建议使用表连接:
select * from a left join b on a.id=b.id WHERE b.id='100'
2023-10-10 12:09:28
sql调优方法:
(1)not in子查询优化
尽量避免子查询select * from a where id not in(select id from b);
select * from a where not exists(select id from b WHERE id ='100')
建议使用表连接:
select * from a left join b on a.id=b.id WHERE b.id='100'