本人认为很实用的几条语句

1）select ... from ...into...

2）insert into ...select ...

3）select ...from ...left join ...on ...

4)case...when...then ...else ... end

Java代码

select * from directory_type

where (case when create_date is null then  sysdate  else create_date end )   >='08/04/2007'

create table test1 as select * from user;-----将user里面的字段以及数据全部复制到test1这张表里面