SQL Query to Join by Comma - Help an assistance

Question

Hi,
Thanks for your help in advance.
Requirement is as follows.
Table1
=======
Col1 Col2
============
1 John
2 Jocky
3 Silk
Table2
========
Col1 Col2
=========
1 John, Marry, Joseph
2 Silk, David
3 Jocky, Prem
I need an sql query where the join condition has to satisfy as follows
Table1.col2=Table2.Col2 (If any of the col2 in table1 matches with Table2.Col2 i need to return the record).
How to do this.
Please guide me on this.

Answer 1

nazzu wrote:
Thanks a lot for your response ...
But if a table1 and table2 had different numbers of rows then ?
I may be behaving like a fool ... but my requrirement is such a fashion.
Please help ...
Thanks again for your help.
Edited by: nazzu on Mar 14, 2013 8:22 AMHi,
try to be clear in your requirement. You mentioned in your initial question:
I need an sql query where the join condition has to satisfy as followsWhat happen if you have different number of rows in table1 and table2?
Rows from table2 will be returned for any match in table1 if you are using a normal join. However if you have 2 rows in table1 that are matching table2 then that row in table2 will return twice.
Let me just show you an example:
WITH table1(col1, col2) AS
   SELECT 1, 'John'  FROM DUAL UNION ALL
   SELECT 2, 'Jocky' FROM DUAL UNION ALL
   SELECT 3, 'Silk'  FROM DUAL UNION ALL
   SELECT 4, 'Marry' FROM DUAL
, table2(col1, col2) AS
   SELECT 1, 'John, Marry, Joseph'  FROM DUAL UNION ALL
   SELECT 2, 'Silk, David'          FROM DUAL UNION ALL
   SELECT 3, 'Jocky, Prem'          FROM DUAL
SELECT t2.col1, t2.col2, t1.col2
  FROM table2 t2
       JOIN table1 t1
          ON(INSTR(', '||t2.col2||',', ', '||t1.col2||',')>0);
      COL1 COL2                COL2_1
         1 John, Marry, Joseph John 
         1 John, Marry, Joseph Marry
         2 Silk, David         Silk 
         3 Jocky, Prem         Jocky As you can see the first row from table2 is returned twice because it matches 2 records on table1.
In case you want to display only rows from table2 which has a match in table1 you can either do a distinct:
SELECT DISTINCT t2.col1, t2.col2
  FROM table2 t2
       JOIN table1 t1
          ON(INSTR(', '||t2.col2||',', ', '||t1.col2||',')>0);
      COL1 COL2              
         1 John, Marry, Joseph
         2 Silk, David       
         3 Jocky, Prem        or use EXISTS operator:
SELECT t2.col1, t2.col2
  FROM table2 t2
WHERE EXISTS (SELECT 1
                 FROM table1 t1
                WHERE INSTR(', '||t2.col2||',', ', '||t1.col2||',')>0
      COL1 COL2              
         1 John, Marry, Joseph
         2 Silk, David       
         3 Jocky, Prem   Regards.
Al