Oracle PL/SQL异常处理

CREATE OR REPLACE PROCEDURE ex_demo1(x NUMBER,  
                                     y NUMBER,
                                     z OUT NUMBER) AS 
   below_min EXCEPTION;
BEGIN 
  IF x<0 THEN
	RAISE below_min;
  END IF;
  z:=x/y;
EXCEPTION
  WHEN ZERO_DIVIDE THEN
	DBMS_OUTPUT.PUT_LINE('除数为0');
  WHEN below_min THEN
	DBMS_OUTPUT.PUT_LINE('被除数小于最小值');
END;
/

SQL> exec ex_demo1(1,0,:z)
除数为0
PL/SQL procedure successfully completed
z
---------

SQL> exec ex_demo1(-1,0,:z)
被除数小于最小值
PL/SQL procedure successfully completed
z
---------

SQL> exec ex_demo1(-1,0,:z)
被除数小于最小值
PL/SQL procedure successfully completed
z
---------

SQL> exec ex_demo1(1,1,:z)
PL/SQL procedure successfully completed
z
---------
1

SQL> select :z from dual;
        :Z
----------
         1
z
---------
1

SQL>