ORA-01489 : result of string concatenation to long - sql

Question

I am creating a dynamic query from a list of tables which are their in my table called : get_table_names
My Query :
SELECT listagg('SELECT '
|| ''''
|| tbl_name
|| ''''
|| ' AS TBL , COUNT(*) as CNT FROM '
|| 'TGT_MB.'
|| tbl_name
|| ' union all'
|| CHAR(10) ) WITH GROUP ( ORDER BY tbl_name) AS sql_str
FROM get_table_names;
My get_table_names as lots of table , at least 70 table names.
The query works fine for 10 tables but more then that it throws the error like below
ORA-01489 : result of string concatenation to long
Their is some option called EXTEND that option I cannot touch as I have low level privileges.
cannot make changes to it until DBA.
Any other work around would be much appreciated like using some XMLAGG or CLOB , BLOB

Answer 1

Can I respectively suggest that when posting a code snippet, make it sure it runs so that people can help you more easily. eg your code above took the following debugging before we could even start to see what you want to do
SQL> SELECT listagg('SELECT '
2 || ''''
3 || table_name
4 || ''''
5 || ' AS TBL , COUNT(*) as CNT FROM '
6 || 'TGT_MB.'
7 || table_name
8 || ' union all'
9 || CHAR(10) ) WITH GROUP ( ORDER BY table_name) AS sql_str
10 FROM dba_tables
11 where owner = 'SCOTT';
|| CHAR(10) ) WITH GROUP ( ORDER BY table_name) AS sql_str
*
ERROR at line 9:
ORA-00936: missing expression
SQL> SELECT listagg('SELECT '
2 || ''''
3 || table_name
4 || ''''
5 || ' AS TBL , COUNT(*) as CNT FROM '
6 || 'TGT_MB.'
7 || table_name
8 || ' union all'
9 || chr(10) ) WITH GROUP ( ORDER BY table_name) AS sql_str
10 FROM dba_tables
11 where owner = 'SCOTT';
|| chr(10) ) WITH GROUP ( ORDER BY table_name) AS sql_str
*
ERROR at line 9:
ORA-00923: FROM keyword not found where expected
Once those fixes are done, we end up here
SQL> SELECT listagg('SELECT '
2 || ''''
3 || table_name
4 || ''''
5 || ' AS TBL , COUNT(*) as CNT FROM '
6 || 'TGT_MB.'
7 || table_name
8 || ' union all'
9 || chr(10),'' ) WITHIN GROUP ( ORDER BY table_name) AS sql_str
10 FROM dba_tables
11 where owner = 'SCOTT';
SQL_STR
-------------------------------------------------------------------------------------
SELECT 'BONUS' AS TBL , COUNT(*) as CNT FROM TGT_MB.BONUS union all
SELECT 'DEPT' AS TBL , COUNT(*) as CNT FROM TGT_MB.DEPT union all
SELECT 'EMP' AS TBL , COUNT(*) as CNT FROM TGT_MB.EMP union all
SELECT 'EMP2' AS TBL , COUNT(*) as CNT FROM TGT_MB.EMP2 union all
SELECT 'SALGRADE' AS TBL , COUNT(*) as CNT FROM TGT_MB.SALGRADE union all
which ultimately blows up when we get too many tables
SQL> SELECT listagg('SELECT '
2 || ''''
3 || table_name
4 || ''''
5 || ' AS TBL , COUNT(*) as CNT FROM '
6 || 'TGT_MB.'
7 || table_name
8 || ' union all'
9 || chr(10),'' ) WITHIN GROUP ( ORDER BY table_name) AS sql_str
10 FROM dba_tables;
FROM dba_tables
*
ERROR at line 10:
ORA-01489: result of string concatenation is too long
Now even if we use a tool (eg
https://github.com/connormcd/listagg_clob) to get the results as a clob, then I imagine you are just going to fire that SQL at the database to get a count of all tables. If that is the case, then why do you need to LISTAGG at all, just build a script to do it, ie
SELECT 'SELECT '
|| ''''
|| table_name
|| ''''
|| ' AS TBL , COUNT(*) as CNT FROM '
|| 'TGT_MB.'
|| table_name
|| ' union all'
FROM dba_tables
Spool that to a file, trim the last union all and run it as a script.
Or even better...think about what benefit the output gives you. Why does anyone need the exact row count? Querying NUM_ROWS from USER_TABLES is probably sufficient.