Oracle学习总结5-存储过程，存储函数，触发器

Posted 2020-09-22

二．存储过程与存储函数：procedure

1.hello world

create or replace procedure hello_world is

begin

  dbms_output.put_line(‘hello world‘);

end hello_world;

 

2. --给指定员工涨100工资，并打印涨前涨后的薪水(存储过程)

create or replace procedure raiseSalary(eno in number) is

     psal emp.sal%type; 

begin

  select sal into psal from emp where empno=eno;

 

  update emp set sal=sal+100 where empno=eno;

 

  dbms_output.put_line(‘涨前：‘||psal||‘涨后：‘||(psal+100));

end raiseSalary;

 

3. --查询某个员工的年收入(存储函数)

 create or replace function queryEmpIncome(eno in number) return number is

  income number;

begin

  select sal*12+nvl(comm,0) into income from emp where empno=eno; 

  return income;

end queryEmpIncome;

 

 

4. --查询某个员工的姓名薪水和职位

create or replace procedure queryEmpInformation(eno in number,pename out varchar2,psal out number,pjob out varchar2) is

 

begin

       select ename,sal,job into pename,psal,pjob from emp where empno=eno;

 

end queryEmpInformation;

 

5. --查询某个员工的年收入的java调用(存储函数调用)

//存储函数调用

    @Test

    public void testFunction(){

        String sql = "{?=call queryEmpIncome(?)}";

       

        Connection conn = null;

        CallableStatement call = null;

       

        try {

            conn=JDBCUtils.getConnection();

            call=conn.prepareCall(sql);

           

            //返回值声明

            call.registerOutParameter(1, OracleTypes.NUMBER);

           

            //对于in参数，赋值

            call.setInt(2,7839);

           

                  

            //执行

            call.execute();

           

            //输出

           

            double income=call.getDouble(1);

           

            System.out.println(income);

        } catch (Exception e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }finally{

            JDBCUtils.release(conn, call, null);

        }

    }

 

6. --查询某个员工的姓名薪水和职位的java调用（存储过程调用）

    

@Test

    public void testProcedure(){

        String sql = "{call queryEmpInformation(?,?,?,?)}";

       

        Connection conn = null;

        CallableStatement call = null;

       

        try {

            conn=JDBCUtils.getConnection();

            call=conn.prepareCall(sql);

           

            //对于in参数，赋值

            call.setInt(1,7839);

           

            //对于out参数，申明

            call.registerOutParameter(2, OracleTypes.VARCHAR);

            call.registerOutParameter(3, OracleTypes.NUMBER);

            call.registerOutParameter(4, OracleTypes.VARCHAR);

           

            //执行

            call.execute();

           

            //输出

           

            String name=call.getString(2);

            double sal=call.getDouble(3);

            String job=call.getString(4);

           

            System.out.println(name+"---"+sal+"---"+job);

        } catch (Exception e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }finally{

            JDBCUtils.release(conn, call, null);

        }

    }

 

 

7.返回多列-使用光标实现。Plsql中建立包和体的结构。然后再由java中的resultset接收

Plsql中：

包：

create or replace package mypackage is

 

       type empcursor is ref cursor;

       procedure queryEmpList(dno in number,empList out empcursor);

 

end mypackage;

 

 

体：

create or replace package body mypackage is

       procedure queryEmpList(dno in number,empList out empcursor)

                 as

                 begin

                         open empList for select * from emp where deptno=dno;

                 end;

end mypackage;

 

 

java调用：

//存储函数调用,返回光标类型的

    @Test

    public void testCursor(){

        String sql = "{call mypackage.QUERYEMPLIST(?,?)}";

       

        Connection conn = null;

        CallableStatement call = null;

        ResultSet rs = null;

        try {

            conn = JDBCUtils.getConnection();

            call = conn.prepareCall(sql);

           

            //对于in参数，赋值

            call.setInt(1,20);

           

            //对于out参数，申明

            call.registerOutParameter(2, OracleTypes.CURSOR);

           

            //执行

            call.execute();

           

            //取出结果

            rs = ((OracleCallableStatement)call).getCursor(2);

            while(rs.next()){

                //取出一个员工

                String name = rs.getString("ename");

                double sal = rs.getDouble("sal");

                System.out.println(name+"\t"+sal);

            }

        } catch (Exception e) {

            e.printStackTrace();

        }finally{

            JDBCUtils.release(conn, call, rs);

        }      

       

    }

 

 

 

 

三．触发器（trigger）

1. 插入员工时候触发

 

create or replace trigger firsttrigger

  after insert on emp

declare

 

begin

  dbms_output.put_line(‘成功插入新员工‘);

end firsttrigger;

 

 

2. --不允许在非工作时间插入数据

create or replace trigger securityemp

  before insert on emp 

declare

 

begin

  if to_char(sysdate,‘day‘) in (‘星期六‘,‘星期日‘)

     or to_number(to_char(sysdate,‘hh24‘)) not between 9 and 17 then

      raise_application_error(-20001,‘禁止在非工作时间插入新员工‘);

   end if; 

 

end securityemp;

 

 

3. --不允许降薪

 

create or replace trigger checksalary

  before update on emp 

  for each row

declare

begin

  if :new.sal<:old.sal then

     raise_application_error(-20002,‘涨后的薪水不能少于涨前的薪水。涨前:‘||:old.sal||‘   涨后:‘||:new.sal);

    end if;

 

end checksalary;