Question about order by and rownum and subqueries.

Question

Can you explain why test 4 below results as it results- with returning no rows?
Identificator "PKG_INTRA_CUSTOMER_SEARCH.NAME" is a package function, which returns value from a variable declared in package body, the function returns value 'e%'.
Please note that tests 1-3 all returned data, but test 4 didn't. Why? My porpouse is that test 4 would also return data.
1. Query without "rownum" and with "Order by" returns 2 records:
select q.*--, rownum
            ,PKG_INTRA_CUSTOMER_SEARCH.NAME
         from
            select c.ID,
               c.NAME,
               c.CODE     
            from V_CUSTOMER c  
            where 1=1 and  lower(c.NAME) like PKG_INTRA_CUSTOMER_SEARCH.NAME 
            order by c.NAME, c.ID
            ) q
10020     Ees Nimi     37810010237     e%
10040     ewewrwe werwerwer          e%2. Query with "rownum" and without "Order by" returns 2 records:
select q.*, rownum
            ,PKG_INTRA_CUSTOMER_SEARCH.NAME
         from
            select c.ID,
               c.NAME,
               c.CODE     
            from V_CUSTOMER c  
            where 1=1 and  lower(c.NAME) like PKG_INTRA_CUSTOMER_SEARCH.NAME 
            --order by c.NAME, c.ID
            ) q
10020     Ees Nimi     37810010237     e%
10040     ewewrwe werwerwer          e%3.Query without "rownum" and with "Order by" returns 2 records:
select q.*--, rownum
            ,PKG_INTRA_CUSTOMER_SEARCH.NAME
         from
            select c.ID,
               c.NAME,
               c.CODE     
            from V_CUSTOMER c  
            where 1=1 and  lower(c.NAME) like PKG_INTRA_CUSTOMER_SEARCH.NAME 
            order by c.NAME, c.ID
            ) q
10020     Ees Nimi     37810010237     e%
10040     ewewrwe werwerwer          e% 4. Query with "rownum" and with "Order by" returns 0 records:
select q.*, rownum
            ,PKG_INTRA_CUSTOMER_SEARCH.NAME
         from
            select c.ID,
               c.NAME,
               c.CODE     
            from V_CUSTOMER c  
            where 1=1 and  lower(c.NAME) like PKG_INTRA_CUSTOMER_SEARCH.NAME 
            order by c.NAME, c.ID
            ) q

Answer 1

Hi,
please reproduce the question in your test database with script below.
My general question is that wht Test5 below returns only 1 row, but Test5 returns 3 rows.
The difference between those two tests is only that one has "order by" clause, the other doesn't have.
I need the "order by" clause to stay, but seems like it is not allowed.
CREATE OR REPLACE
PACKAGE PACKAGE1 AS
function NAME return varchar2;
END PACKAGE1;
CREATE OR REPLACE
PACKAGE body PACKAGE1 AS
function NAME return varchar2
is
begin
   return 'e%';
end NAME;
END PACKAGE1;
select PACKAGE1.name from dual--e%
create table Tbl AS
   (SELECT 'e2b' Col1, 'A' Col2, 'AA' Col3 FROM dual
   UNION
   SELECT 'e3b', 'B','BB' FROM dual
--Test5:  
select q.*, rownum pos, PACKAGE1.name f         
         from
            select c.col1,
               c.col2,
               c.col3     
            from Tbl c  
            where 1=1 and  lower(c.col1) like PACKAGE1.name                      
            order by c.col2, c.col1
            ) q                               
            union all
         select '111' , '111' , '111' , 0 pos, PACKAGE1.name f from dual   --return 1 row
--Test6
select q.*, rownum pos, PACKAGE1.name f         
         from
            select c.col1,
               c.col2,
               c.col3     
            from Tbl c  
            where 1=1 and  lower(c.col1) like PACKAGE1.name                      
            --order by c.col2, c.col1
            ) q                               
            union all
         select '111' , '111' , '111' , 0 pos, PACKAGE1.name f from dual   --return 3 rowsEdited by: CharlesRoos on Feb 17, 2010 5:30 AM