我是用了查询的控件自动产生了in ( )而选择的结果添加到括弧中 但是我试了 select * from biao where c1 in (select c1 from biao where c1 is null ) select * from biao where c1 in (null) 这样都不行。不知道这个括弧中要怎么写
select * from biao a where exists(select 1 from biao where id=a.id and c1 is null)
我的意思是说select * from biao where c1 in ( ) 这个结构是不能改了, 构造SQL只能在这个括弧中
为何一定要用c1作条件,以关键字作查询不行吗? select * from biao where id in (select id from biao where c1 is null)
不能找到满足条件的数据
但是我试了
select * from biao where c1 in (select c1 from biao where c1 is null )
select * from biao where c1 in (null)
这样都不行。不知道这个括弧中要怎么写
这个结构是不能改了,
构造SQL只能在这个括弧中
select * from biao where id in (select id from biao where c1 is null)