t1
-----------------------
id A B Ct2
---------------------
id F如果满足条件:t1.id = t2.id , t1.B = '0', F = null
就把F的值设置为C
请问如何实现 ?
-----------------------
id A B Ct2
---------------------
id F如果满足条件:t1.id = t2.id , t1.B = '0', F = null
就把F的值设置为C
请问如何实现 ?
where F is null
and exists(select 'X' from t2 where ta.id = id and tb.B = '0' and F is null));
set t_2.F = 'C'
where exists (
select 1
from t1 t_1
where t_1.id = t_2.id
and t_1.B = '0'
and t_2.F is null
);试试看~~
set t_2.F = 'C'
where exists (
select 1
from t1 t_1
where t_1.id = t_2.id
and t_1.B = '0'
and t_2.F is null
);C不是一字符,而是表t2的字段