How to drop all user tables?

Question

How can I drop all user tables in oracle?

I have problem with constraints. When I disable all it is still no possible.

Answer 1

SELECT 'DROP TABLE "' || TABLE_NAME || '" CASCADE CONSTRAINTS;' 
FROM user_tables;

user_tables is a system table which contains all the tables of the user the SELECT clause will generate a DROP statement for every table you can run the script

Answer 2

Another answer that worked for me is (credit to http://snipt.net/Fotinakis/drop-all-tables-and-constraints-within-an-oracle-schema/)

BEGIN

FOR c IN (SELECT table_name FROM user_tables) LOOP
EXECUTE IMMEDIATE ('DROP TABLE "' || c.table_name || '" CASCADE CONSTRAINTS');
END LOOP;

FOR s IN (SELECT sequence_name FROM user_sequences) LOOP
EXECUTE IMMEDIATE ('DROP SEQUENCE ' || s.sequence_name);
END LOOP;

END;

Note that this works immediately after you run it. It does NOT produce a script that you need to paste somewhere (like other answers here). It runs directly on the DB.

Answer 3

begin
  for i in (select 'drop table '||table_name||' cascade constraints' tbl from user_tables) 
  loop
     execute immediate i.tbl;
  end loop;
end;