複製表資料

複製表結構以及資料：
    create table new as select * from old
複製資料到一個相同的表：
    insert into sametable select * from old
只複製表結構：
    create table new as select * from old where 1 = 2   

樹形結構表查詢

查詢某個節點下面的所有子節點

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

查詢某個節點上面的所有父節點

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

查詢某個節點的根節點

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

查詢某個節點的所有葉子節點

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

查詢某個節點的父親節點路徑

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

查詢某個節點的子節點路徑

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

case when表示式

(case when b.oritation = '0'
    then 100
    case when b.oritation = '1'
    then 200
else 300) as id 
 

ege:

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 "

更新設定資料

有AB表，A表資料完整，將A表的某些欄位更新到B中

update B set B(B1,B2,B3) = (select A1,B2,B3 from A,B where A.id = B.id)