现在需要查询unit表中,在information表中有的unit_name,是否存在重复的数据。以下哪些逻辑可以实现?
A. select name,count(*) from unit u where u.name in (select unit name from informati on i where i.unit name = u.name)group by u.name having count(*) > 1; 。
B. select name,count(1) from unit u join inf ormation i on u.unit name=.unit name group by name where count(1) >1;
C. select name,count(*) from unit u where exists (select 1 from information i where i.unit_name = u.name)group by name having count(*) > 1;
D. select name,count(1) from unit u join inf ormation i on u.unit name=.unit name :