MySQL group_contat in ORACLE

admin — Thu, 02 Apr 2009 11:39:30 +0000

Here is a way to add the group_concat function to ORACLE. After that you’ll be able to do just like in MySQL.

first you’ll need to create a new object type:

create or replace TYPE t_string_agg AS OBJECT ( g_string VARCHAR2(32767),


  STATIC FUNCTION ODCIAggregateInitialize(sctx  IN OUT  t_string_agg)

    RETURN NUMBER,
  MEMBER FUNCTION ODCIAggregateIterate(self   IN OUT  t_string_agg,

                                       value  IN      VARCHAR2 )

     RETURN NUMBER,
  MEMBER FUNCTION ODCIAggregateTerminate(self         IN   t_string_agg,

                                         returnValue  OUT  VARCHAR2,

                                         flags        IN   NUMBER)

    RETURN NUMBER,

MEMBER FUNCTION ODCIAggregateMerge(self IN OUT t_string_agg, ctx2 IN t_string_agg) RETURN NUMBER );

then create a function using the newly created type :

create or replace FUNCTION tring_concat (p_input VARCHAR2) RETURN VARCHAR2 PARALLEL_ENABLE AGGREGATE USING t_string_agg;

now try it with SCOTT’s schema

COLUMN employees FORMAT A50


SELECT deptno, group_concat(ename) AS employees

FROM   emp

GROUP BY deptno;
    DEPTNO EMPLOYEES

---------- --------------------------------------------------

        10 CLARK,KING,MILLER

        20 SMITH,FORD,ADAMS,SCOTT,JONES

        30 ALLEN,BLAKE,MARTIN,TURNER,JAMES,WARD

3 rows selected.

that could be quite useful to add this function to the SYS schema and then create a public synonym. this way the function will be available to any user of the database.

bigjim-network » group by

MySQL group_contat in ORACLE