Oracle/Sql: Wm_Concat & Order By

ORACLE/SQL: wm_concat & order by

You can't reference ODB.TASK_CARD_CONTROL.CONTROL_CATEGORY from outside the inner query. Try:

SELECT TASK_CARD, WM_CONCAT(code) as ZONES
FROM (SELECT TASK_CARD, CODE, CONTROL_CATEGORY FROM ODB.TASK_CARD_CONTROL 
      WHERE ODB.TASK_CARD_CONTROL.CONTROL_CATEGORY = 'ZONE'
      ORDER BY CODE)
GROUP BY TASK_CARD

Change separator of WM_CONCAT function of Oracle 11gR2

You might want to use LISTAGG.

SELECT col_id, 
       LISTAGG(col_text, '|') WITHIN GROUP (ORDER BY col_text) text
  FROM table1
 GROUP BY col_id

Output:

| COL_ID |            TEXT |
----------------------------
|    111 | This|a|is|test. |

SQLFiddle

UPDATE If you need to get distinct text values in a list

SELECT col_id, 
       LISTAGG(col_text, '|')
         WITHIN GROUP (ORDER BY col_text) text
  FROM 
(
  SELECT DISTINCT col_id, col_text
    FROM table1
)
 GROUP BY col_id

SQLFiddle

How to concatenate multiple rows order by sequence in Oracle10g

Never use WM_CONCAT. Read Why not use WM_CONCAT function in Oracle?

See this topic https://stackoverflow.com/a/28758117/3989608.

It is undocumented, and any application which relies on WM_CONCAT will not work once upgraded to 12c because it has been removed from the latest 12c version.

There are many ways of doing string-aggregation, depending on the database version. See few examples below:

11gR2

Use LIASTAGG:

SQL> SELECT grp,
  2    listagg(command, ',') WITHIN GROUP(
  3  ORDER BY seq) command
  4  FROM t
  5  GROUP BY grp;

GRP COMMAND
--- --------------------------------------------------------------------------------------------
ONE <?xml version=1.0 encoding=UTF-8?>,<message1>MESSAGE</message1>,<message2>MESSAGE</message2>
TWO <?xml version=1.0 encoding=UTF-8?>,<message2>MESSAGE</message2>,<message9>MESSAGE</message9>

SQL>

9i and up

Use ROW_NUMBER() and SYS_CONNECT_BY_PATH:

SQL> SELECT grp,
  2         LTRIM(MAX(SYS_CONNECT_BY_PATH(command,','))
  3         KEEP (DENSE_RANK LAST ORDER BY seq),',') command
  4  FROM   (SELECT grp,
  5                 command,
  6                 seq,
  7                 ROW_NUMBER() OVER (PARTITION BY grp ORDER BY seq) AS curr,
  8                 ROW_NUMBER() OVER (PARTITION BY grp ORDER BY seq) -1 AS prev
  9          FROM   t)
 10  GROUP BY grp
 11  CONNECT BY prev = PRIOR curr AND grp = PRIOR grp
 12  START WITH curr = 1;

GRP COMMAND
--- --------------------------------------------------------------------------------------------
ONE <?xml version=1.0 encoding=UTF-8?>,<message1>MESSAGE</message1>,<message2>MESSAGE</message2>
TWO <?xml version=1.0 encoding=UTF-8?>,<message2>MESSAGE</message2>,<message9>MESSAGE</message9>

SQL>

Concatenate Over Oracle

OP is on Oracle 10g, and LISTAGG was introduced in 11g Release 2.

Therefore, in Oracle version prior to 11g where LISTAGG is not supported, you could use ROW_NUMBER() and SYS_CONNECT_BY_PATH functions.

SELECT fruit,
  LTRIM(MAX(SYS_CONNECT_BY_PATH(number,','))
  KEEP (DENSE_RANK LAST ORDER BY curr),',') AS fruits_agg
  FROM   (SELECT fruit,
                number,
                ROW_NUMBER() OVER (PARTITION BY fruit ORDER BY number) AS curr,
                ROW_NUMBER() OVER (PARTITION BY fruit ORDER BY number) -1 AS prev
         FROM   table_name)
  GROUP BY fruit
  CONNECT BY prev = PRIOR curr AND fruit = PRIOR fruit
 START WITH curr = 1;

NOTE

Never use WM_CONCAT since it is an undocumented feature and it has been removed from 12c version.

Any application which has had been relying on wm_concat function will not work once upgraded to 12c. Since, it has been removed. See Why not use WM_CONCAT function in Oracle?

SQL> select banner from v$version where rownum = 1;

BANNER
----------------------------------------------------------------------------
Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit Production

SQL> SELECT object_name
  2  FROM dba_objects
  3  WHERE owner='WMSYS'
  4  AND object_name LIKE 'WM\_%' ESCAPE '\';

OBJECT_NAME
----------------------------------------------------------------------------
WM_REPLICATION_INFO
WM_RDIFF
WM_PERIOD
WM_PERIOD
WM_OVERLAPS
WM_MEETS
WM_LESSTHAN
WM_LDIFF
WM_INTERSECTION
WM_INSTALLATION
WM_GREATERTHAN
WM_EVENTS_INFO
WM_ERROR
WM_ERROR
WM_EQUALS
WM_DDL_UTIL
WM_DDL_UTIL
WM_CONTAINS
WM_COMPRESS_BATCH_SIZES
WM_COMPRESSIBLE_TABLES

20 rows selected.

SQL>

You will receive an “invalid identifier” error:

SQL> SELECT banner FROM v$version;

BANNER
----------------------------------------------------------------------------
Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit Production
PL/SQL Release 12.1.0.1.0 - Production
CORE    12.1.0.1.0      Production
TNS for 64-bit Windows: Version 12.1.0.1.0 - Production
NLSRTL Version 12.1.0.1.0 - Production

SQL> SELECT deptno, wm_concat(ename) FROM emp;
SELECT deptno, wm_concat(ename) FROM emp
               *
ERROR at line 1:
ORA-00904: "WM_CONCAT": invalid identifier

Therefore, there is no point relying on an undocumented feature which is no more made available in latest versions.

Oracle: stragg and wm_concat return data in the incorrect order

stragg is a user-defined aggregate function. Various folks (Tom Kyte, Tim Hall, and many others) have written various versions of that function. Not knowing which of these functions you started with or what customizations you made to it, I'll have to speculate a bit. In general, though, those functions are not doing any sort of internal sort so the order that values appear in the list is arbitrary. It would be perfectly valid for the function to return one order today and a different order tomorrow or for the order to be different in different sessions.

Various people have also written user-defined aggregate functions that return lists of data in a sorted order. For example, Gary Myers has a variant of the stragg function that sorts the elements alphabetically. You could use that and customize the function to sort the results by whatever you'd like to sort them by.

If you are using Oracle 11.2 or later, though, you'd be much better off using the LISTAGG analytic function which makes it much easier to specify (or change) the way you are sorting data.

Two wm_concat in a single query

You could either use SYS_CONNECT_BY_PATH or XMLAGG as alternatives to WM_CONCAT (unsupported). An example for SYS_CONNECT_BY_PATH is found in an Oracle Forum discussion here. I created a SQL Fiddle using XMLAGG here.

Also, you can use the ORDER BY clause (as shown in the examples), if you need the values concatenated in a certain order.

References:

LISTAGG alternative in 10g

Related Question on SO

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