WHENEVER SQLERROR EXIT SQL.SQLCODE

BEGIN
  EXECUTE IMMEDIATE q'[
    CREATE TABLE dds_employees (
      employee_id NUMBER PRIMARY KEY,
      first_name  VARCHAR2(50) NOT NULL,
      last_name   VARCHAR2(50) NOT NULL,
      email       VARCHAR2(80) NOT NULL,
      manager     VARCHAR2(80),
      ssn         VARCHAR2(30),
      salary      NUMBER(12,2),
      phone       VARCHAR2(30)
    )
  ]';
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -955 THEN
      RAISE;
    END IF;
END;
/