Oracle中自定义函数无参数输入参数输出参数

-- 19-1:建立无参数的函数CREATE OR REPLACE FUNCTION cur_datetimeRETURN VARCHAR2ISBEGINRETURN TO_CHAR(sysdate,'YYYY年MM月DD日HH24时MI分SS秒');END;/-- 19-2:建立带有输入参数的函数CREATE OR REPLACE FUNCTION get_sal(name VARCHAR2)RETURN NUMBERAS

-- 19-1:建立无参数的函数 CREATE OR REPLACE FUNCTION cur_datetime RETURN VARCHAR2 IS BEGIN RETURN TO_CHAR(sysdate, 'YYYY"年"MM"月"DD"日"HH24″时"MI"分"SS"秒"'); END; / -- 19-2:建立带有输入参数的函数 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; END; / -- 19-3:建立带有输出参数的函数 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:建立带有输入输出参数的函数 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:建立结果缓存函数 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:调用无参数的函数 BEGIN dbms_output.put_line(cur_datetime); END; / -- 19-7:调用带有输入参数的函数 BEGIN dbms_output.put_line('工资:'||get_sal('&name')); END; / -- 19-8:调用带有输出参数的函数 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||',岗位:'||v_job); END; / -- 19-9:调用带有输入输出参数的函数 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||',新工资:'||v_salchg); END; / -- 19-10:使用位置传递为参数传递变量和数据 SELECT get_sal('&name') 工资 FROM dual; -- 19-11:使用名称传递为参数传递变量和数据 VAR salary NUMBER EXEC :salary:=get_sal(name=>'&name') -- 19-12:使用组合传递为参数传递变量和数据 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语句中调用pl/sql函数 SELECT get_sal(name=>'scott') salary FROM dual; -- 19-14:使用异常处理 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,'该雇员不存在'); END; / -- 19-15:使用纪录类型作为返回类型 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,'该雇员不存在'); END; / DECLARE emp_record emp%ROWTYPE; BEGIN emp_record:=get_info(&eno); dbms_output.put_line('姓名:'||emp_record.ename||',部门号:'||emp_record.deptno); END; / -- 19-16:使用集合类型作为返回类型 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,'该部门不存在'); 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:删除函数 DROP FUNCTION get_name; -- 19-18:显示编译错误 SHOW ERRORS -- 19-19:确定函数状态 SELECT object_name FROM user_objects WHERE status='INVALID' AND object_type='FUNCTION'; -- 19-20:编译函数 ALTER FUNCTION get_info COMPILE; -- 19-21:查看函数代码 SELECT text FROM user_source WHERE;