WHENEVER SQLERROR EXIT SQL.SQLCODE

BEGIN
  EXECUTE IMMEDIATE q'[
    CREATE TABLE dds_orders (
      order_id      NUMBER GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
      customer_name VARCHAR2(100) NOT NULL,
      region        VARCHAR2(30) NOT NULL,
      seller        VARCHAR2(60) NOT NULL,
      amount        NUMBER(12,2) NOT NULL,
      margin        NUMBER(12,2) NOT NULL
    )
  ]';
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -955 THEN
      RAISE;
    END IF;
END;
/