有点难度的pl/sql

[yangguang1219]

select ... from a_dept where id =memberid),'omrole',
(select displayname from tib_role where id=memberid),'omstaff',
(select displayname from tib_staff where id=memberid) displayname,
decode(a.memberkind,'omdept',(select kind as deptkind from a_dept where id=memberid),'omrole',
(select '' as deptkind from tib_role where id=memberid),'omstaff',
(select '' as deptkind from tib_staff where id=memberid))deptkind
from a_orgrelation a start with a.memberid=:key connect by prior a.parentguid=a.guid



select ... from dual where :1=1 union select 2 as scope,t.column_name,
decode(t.data_type,'char',1,
'varchar2',12,
'number', 3,
'long', -1,
'date', 93,
'raw', -3,
'long raw',-4,1111)as data_type,
t.data_type as type_name,
decode(t.data_precision,null,t.data_length,t.data_precision) as column_size,
0 as buffer_length,
t.data_scale as decimal_digits,
l as pseudo_column
from all_tab_columns t,
all_ind_columns i where :2=1 and
t.table_name:=3 and
t.owner like:4 escape '/' and
t.nullable !=:5 and
t.owner=i.table_owner and
t.table_name =i.table_name and
t.column_name =i.column_name

想知道这两段语句实现的功能 ？
解释结合变量？

[jiezhi]

第一個是一個tree結構的查詢。
第二個是一個帶參數的查詢語句。

[jiezhi]

:1,:2這樣的會在實際執行中被傳入參數所代替。

[yangguang1219]

start with a.memberid=:key connect by prior a.parentguid=a.guid
这句话怎么理解？

[yangguang1219]

能不能用scott里面的emp表做一个完整的例子，有实际结果出来（直观一点）谢谢

[yangguang1219]

select *from dual where :1=1
SP2-0552: 未说明结合变量"1", 应该怎样说明？

[beckhambobo]

第一条语句是一个tree型语句
第二条语句是引用了all_tab_columns ,all_ind_columns 这两个系统表

但t.table_name:=3 --这句话出现在查询语句中，会出错

[beckhambobo]

第一条语句是一个tree型语句
第二条语句是引用了all_tab_columns ,all_ind_columns 这两个系统表

但t.table_name:=3 --这句话出现在查询语句中，会出错

[beckhambobo]

declare
num number;
begin
execute immediate 'select 1 from dual where :1=1' into num;
dbms_output.put_line(num);
end;
/

[yangguang1219]

刚才是我笔误正确的是：t.table_name=:3 and

[yangguang1219]

我的qq是42008282想和大家交个朋友。
t.owner like:4 escape '/' and 这一句escape '/'是什么意思

[jiezhi]

escape '/' : 忽略 '/'

[jiezhi]

escape '/' : 忽略 '/'

[beckhambobo]

http://gigabase.idi.ntnu.no/oradoc/server.901/a90125/queries2.htm#2053937

[beckhambobo]

http://expert.csdn.net/Expert/topic/1551/1551178.xml?temp=.3297693