Oracle: If Table Exists

Question

I\'m writing some migration scripts for an Oracle database, and was hoping Oracle had something similar to MySQL\'s IF EXISTS construct.

Specifically, w

Answer 1

I prefer to specify the table and the schema owner.

Watch out for case sensitivity as well. (see "upper" clause below).

I threw a couple of different objects in to show that is can be used in places besides TABLEs.

.............

declare
   v_counter int;
begin
 select count(*) into v_counter from dba_users where upper(username)=upper('UserSchema01');
   if v_counter > 0 then
      execute immediate 'DROP USER UserSchema01 CASCADE';
   end if; 
end;
/



CREATE USER UserSchema01 IDENTIFIED BY pa$$word
  DEFAULT TABLESPACE users
  TEMPORARY TABLESPACE temp
  QUOTA UNLIMITED ON users;

grant create session to UserSchema01;  

And a TABLE example:

declare
   v_counter int;
begin
 select count(*) into v_counter from all_tables where upper(TABLE_NAME)=upper('ORDERS') and upper(OWNER)=upper('UserSchema01');
   if v_counter > 0 then
      execute immediate 'DROP TABLE UserSchema01.ORDERS';
   end if; 
end;
/