RETURN NUMBER

AS

v_sal emp.sal%TYPE;

BEGIN

SELECT sal INTO v_sal FROM emp WHERE upper(ename)=upper(name);

RETURN v_sal;

END;

/

-- 19-3:建立帶有輸出參數的函數

CREATE OR REPLACE FUNCTION get_info

(eno NUMBER,title OUT VARCHAR2) RETURN VARCHAR2

AS

name emp.ename%TYPE;

BEGIN

SELECT ename,job INTO name,title FROM emp

WHERE empno=eno;

RETURN name;

END;

/

-- 19-4:建立帶有輸入輸出參數的函數

CREATE OR REPLACE FUNCTION get_upd_info

(eno NUMBER,sal_chg IN OUT NUMBER) RETURN VARCHAR2

AS

name emp.ename%TYPE;

BEGIN

UPDATE emp SET sal=sal+sal_chg WHERE empno=eno

RETURNING ename,sal INTO name,sal_chg;

RETURN name;

END;

/

-- 19-5:建立結果緩存函數

CREATE OR REPLACE FUNCTION get_name(no VARCHAR2)

RETURN NUMBER RESULT_CACHE RELIES_ON(emp)

AS

v_name emp.ename%TYPE;

BEGIN

SELECT ename INTO v_name FROM emp WHERE empno=no;

RETURN v_name;

END;

/

-- 19-6:調用無參數的函數

BEGIN

dbms_output.put_line(cur_datetime);

END;

/

-- 19-7:調用帶有輸入參數的函數

BEGIN

dbms_output.put_line('工資:'||get_sal('&name'));

END;

/

-- 19-8:調用帶有輸出參數的函數

DECLARE

v_name emp.ename%TYPE;

v_job emp.job%TYPE;

BEGIN

v_name:=get_info(&eno,v_job);

dbms_output.put_line('姓名:'||v_name||',崗位:'||v_job);

END;

/

-- 19-9:調用帶有輸入輸出參數的函數

DECLARE

v_empno emp.empno%TYPE;

v_name emp.ename%TYPE;

v_salchg emp.sal%TYPE;

BEGIN

v_empno:=&eno;

v_salchg:=&incre;

v_name:=get_upd_info(v_empno,v_salchg);

dbms_output.put_line('姓名:'||v_name||',新工資:'||v_salchg);

END;

/

-- 19-10:使用位置傳遞為參數傳遞變量和數據

SELECT get_sal('&name') 工資 FROM dual;

-- 19-11:使用名稱傳遞為參數傳遞變量和數據

VAR salary NUMBER

EXEC :salary:=get_sal(name=>'&name')

-- 19-12:使用組合傳遞為參數傳遞變量和數據

VAR name VARCHAR2(10)

VAR sal_chg NUMBER

EXEC :sal_chg:=200

EXEC :name:=get_upd_info(&eno,:sal_chg)

PRINT name sal_chg

-- 19-13:在sql語句中調用pl/sql函數

SELECT get_sal(name=>'scott') salary FROM dual;

-- 19-14:使用異常處理

CREATE OR REPLACE FUNCTION get_sal(name VARCHAR2)

RETURN NUMBER

AS

v_sal emp.sal%TYPE;

BEGIN

SELECT sal INTO v_sal FROM emp

WHERE upper(ename)=upper(name);

RETURN v_sal;

EXCEPTION

WHEN NO_DATA_FOUND THEN

RAISE_APPLICATION_ERROR(-20000,'該雇員不存在');

END;

/

-- 19-15:使用紀錄類型作為返回類型

CREATE OR REPLACE FUNCTION get_info

(eno NUMBER) RETURN emp%ROWTYPE

IS

emp_record emp%ROWTYPE;

BEGIN

SELECT * INTO emp_record FROM emp WHERE empno=eno;

RETURN emp_record;

EXCEPTION

WHEN NO_DATA_FOUND THEN

RAISE_APPLICATION_ERROR(-20000,'該雇員不存在');

END;

/

DECLARE

emp_record emp%ROWTYPE;

BEGIN

emp_record:=get_info(&eno);

dbms_output.put_line('姓名:'||emp_record.ename||',部門號:'||emp_record.deptno);

END;

/

-- 19-16:使用集合類型作為返回類型

CREATE OR REPLACE TYPE ename_table_type IS TABLE OF VARCHAR2(10);

/

CREATE OR REPLACE FUNCTION get_name

(dno NUMBER) RETURN ename_table_type IS

ename_table ename_table_type;

BEGIN

SELECT ename BULK COLLECT INTO ename_table FROM emp WHERE deptno=dno;

RETURN ename_table;

EXCEPTION

WHEN NO_DATA_FOUND THEN

RAISE_APPLICATION_ERROR(-20099,'該部門不存在');

END;

/

DECLARE

ename_table ename_table_type;

BEGIN

ename_table:=get_name(&dno);

FOR i IN 1..ename_table.COUNT LOOP

dbms_output.put_line('姓名：'||ename_table(i));

END LOOP;

END;

/

-- 19-17:刪除函數

DROP FUNCTION get_name;

-- 19-18:顯示編譯錯誤

SHOW ERRORS

-- 19-19:確定函數狀態

SELECT object_name FROM user_objects WHERE status='INVALID' AND object_type='FUNCTION';

-- 19-20:編譯函數

ALTER FUNCTION get_info COMPILE;

-- 19-21:查看函數代碼

SELECT text FROM user_source WHERE name='GET_INFO';

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