数据库表关联查询
有A和B两个表，两个表同过name关联，现在想找出A中有而B中没有的name，怎么用sql语句查询
[解决办法]

select name from a where not exists(select 1 from b where a.name=b.name);

[解决办法]
select name from a,b where a.name = b.name(+) and b.name is null