问2个SQL语句

1.建立一个一模一样的数据表,就数据表名不一样?

select * into tb1 from tb2 where 1=0



2如果我想左连接查2个表中book_num不一样的记录,请问如何实现,



select * from t1 where id not in(select id from t2)

or

select * from t2 where id not in(select id from t1)

1.建立一个一模一样的数据表,就数据表名不一样?

select * into tb1 from tb2

 

2.如何合并查询,如何查不符合条件的记录....例如: 

select   a.*,b.bj,b.i_date   from   book1   a     left   outer     join   book2   b     on   a.book_num=b.book_num     

上面这句是查询,是左连接查询a表和b表中book_num相同的记录,如果我想左连接查2个表中book_num不一样的记录,请问如何实现,谢谢!



select a.* from book1 where book_num not in (select book_num from book2)

select a.* from book2 where book_num not in (select book_num from book1)