drop table if exists test
DECLARE -- Oracle
existing_table number;
BEGIN
SELECT count(*) into existing_table FROM ALL_TABLES
WHERE TABLE_NAME = 'table_name' AND OWNER = 'owner';
IF existing_table = 1 then
EXECUTE IMMEDIATE 'DROP TABLE owner.table_name';
END IF;
END;
/
CREATE TABLE owner.table_name (BDAY DATE, [...]);