SQL 高階語法

複製表結構以及資料：

create table new as select * from old
複製資料到乙個相同的表：
insert into sametable select * from old
只複製表結構：
create table new as select * from old where 1 = 2

select * from tb_deptconfig start with parent_id = -1 connect by prior id = parent_id

select * from tb_dept start with id = '44060' connect by prior parent_id = id;

select name,connect_by_root(name),connect_by_root(id) from tb_deptconfig   start with id = '440600000094' connect by prior parent_id = id;

select * from tb_deptconfig where connect_by_isleaf = 1 start with parent_id = '-1' connect by  parent_id =prior id;

select name,sys_connect_by_path(name,'--') from tb_deptconfig start with id = '44060' connect by prior parent_id = id;

select name,sys_connect_by_path(name,'--') from tb_deptconfig start with  parent_id = -1 connect by prior id = parent_id

(case when b.oritation = '0'

then 100
case when b.oritation = '1'
then 200
else 300) as id

select 

b.[_id] ,
b.orientation, 
c.[user_id], 
from record b 
left join 
(select user_id,name from contact 
union 
select user_id,name from friendcontact) c 
on (case when b.orientation = '0' then 10 
else b.[user_id] end ) = c.[user_id] 
where b.[user_id]= "+muserid +
" order by b.receive_time desc "

update b set b(b1,b2,b3) = (select a1,b2,b3 from a,b where a.id = b.id)

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