Dynamic DDL execution using DBMS_SQL

Question

Hello,
I've done a set of PL/SQL blocks that helps me to automate some tasks of my schema for better productivity. It concerns the most of the time :
- activate/deactivate foreign keys and constraints
- delete and recreate a set of objects
- etc
My routines execute a query on the dictionary to construct other queries to manipulate my objects. It works fine for a couple of comands:
-- DISABLE CONSTRAINTS
DECLARE
CURSOR curs
IS
SELECT 'ALTER TABLE "'
|| table_name
|| '" DISABLE CONSTRAINT "'
|| constraint_name
|| '"' text
FROM SYS.user_constraints
WHERE constraint_type = 'R' AND owner = r_owner;
c_row curs%ROWTYPE;
cursor_name INTEGER;
BEGIN
FOR c_row IN curs
LOOP
cursor_name := DBMS_SQL.open_cursor;
DBMS_SQL.parse (cursor_name, c_row.text, DBMS_SQL.native);
DBMS_SQL.close_cursor (cursor_name);
END LOOP;
END;
-- TRUNCATE ALL TABLES
DECLARE
CURSOR curs
IS
SELECT 'TRUNCATE TABLE "' || table_name || '"' text
FROM SYS.user_tables
WHERE partitioned = 'NO';
c_row curs%ROWTYPE;
cursor_name INTEGER;
BEGIN
FOR c_row IN curs
LOOP
cursor_name := DBMS_SQL.open_cursor;
DBMS_SQL.parse (cursor_name, c_row.text, DBMS_SQL.native);
DBMS_SQL.close_cursor (cursor_name);
END LOOP;
END;
It works fine, but it's not the case for this one:
-- DROP ALL SCHEMA OBJECTS
DECLARE
CURSOR curs
IS
SELECT 'DROP '
|| object_type
|| ' "'
|| object_name
|| '"'
|| DECODE (object_type, 'TABLE', ' CASCADE CONSTRAINTS PURGE', '')
|| ';' text
FROM user_objects
WHERE object_type NOT IN ('INDEX','TRIGGER');
c_row curs%ROWTYPE;
cursor_name INTEGER;
BEGIN
FOR c_row IN curs
LOOP
cursor_name := DBMS_SQL.open_cursor;
DBMS_OUTPUT.put_line (c_row.text);
--DBMS_SQL.parse (cursor_name, c_row.text, DBMS_SQL.native);
DBMS_SQL.close_cursor (cursor_name);
END LOOP;
END;
The DBMS Output gives me successfuly de set of commands like:
DROP TABLE "T1" CASCADE CONSTRAINTS PURGE;
DROP SEQUENCE "SEQ1";
and so on...
When I uncomment the DBMS_SQL.parse for this one... I receive the following error:
ORA-00911: invalid character
ORA-06512: at "SYS.DBMS_SYS_SQL", line 906
ORA-06512: at "SYS.DBMS_SQL", line 39
ORA-06512: at line 21
I can't figure it out.... any ideas ?
Thanks in advance
Bruno Lavoie

Answer 1

What I prefere for such a task is to use SQL*PLUS scripts.
Select and Spool all the commands (DROP, ALTER, whatever) to some sql file. THen run this file.
The advantage is that you can much better see which commands are actually executed.