oracle 自動新增欄位 procedure

SET SERVEROUTPUT ON; --ENABLE

EXEC DBMS_OUTPUT.ENABLE(1000000);

DECLARE

B NUMBER;

BEGIN

SELECT COUNT(*)

INTO B

FROM USER_TAB_COLUMNS

WHERE TABLE_NAME = 'TABLE_A' AND COLUMN_NAME = 'COLUMN_A';

IF B = 0

THEN

EXECUTE IMMEDIATE 'ALTER TABLE TABLE_A ADD(COLUMN_A NVARCHAR2(100) DEFAULT ''IB'' )';

DBMS_OUTPUT.PUT_LINE('ALTER TABLE TABLE_A ADD(COLUMN_A NVARCHAR2(100) DEFAULT ''IB'' )');

END IF;

END;