PL/SQL 简单学习(2)

--标量类型
--1.varchar2(n)
--2.char(n)
--3.number(p,s)
--4.DATE
--5.TIMESTAMP
--6.BOOLEAN
select * from employees

declare
  emp_name employees.last_name%TYPE;
  --获取已知字段的类型
  emp_sal employees.salary%type;
  -- 赋值  :=     标量
  emp_suishou CONSTANT number(3,2) :=0.03;
  emp_overMoney number(9,2);
  begin
    select last_name,salary
            into emp_name,emp_sal
            from employees
     where employee_id=&employee_id;
     emp_overMoney:=emp_sal-(emp_sal*emp_suishou);
     DBMS_OUTPUT.put_line('员工姓名:'||emp_name);
     DBMS_OUTPUT.put_line('税前工资:'||emp_sal);
     DBMS_OUTPUT.put_line('税后工资:'||emp_overMoney);
     exception
       when NO_DATA_FOUND
         THEN
           DBMS_OUTPUT.put_line('没获取到任何数据');
           
    end;
--if语句
declare
  v_sal number(9,2);
 begin
   select salary into v_sal from employees
   --trim('&empname')  可以输入汉字
   where last_name=trim('&empname');
   if v_sal <8000
     then
       update employees set
        salary=v_sal+500 where last_name=trim('&empname');
   elsif v_sal >18000
     then
     update employees set
        salary=v_sal-500 where last_name=trim('&empname');
   else
      DBMS_OUTPUT.put_line('维持不变!');
   end if;
 end;

---CASE  语句
declare
  v_sal number(9,2);
 begin
   select salary into v_sal from employees
   --trim('&empname')  可以输入汉字
   where last_name=trim('&empname');
   CASE v_sal
     when 8000
     then
       update employees set
        salary=v_sal+500 where last_name=trim('&empname');
     when 12000
     then
     update employees set
        salary=v_sal-500 where last_name=trim('&empname');
   else
      DBMS_OUTPUT.put_line('维持不变!');
   end CASE;
 end;
 
 --循环语句
 --1.loop
 declare
   i int := 1;
   begin
         loop
            DBMS_OUTPUT.put_line(i);
            i:=i+1;
            exit when i>10;
         end loop;
     end;
 --2.while循环
 
 declare
   i int := 1;
   begin
          while i<=10 loop
             DBMS_OUTPUT.put_line(i);
            i:=i+1;
            end loop;
     end;
--3 for 循环
 declare
   i int := 1;
   begin
          for i in 1..10 loop
             DBMS_OUTPUT.put_line(i);
            end loop;
     end;
     

select * from employees


--定义一个游标(在查询有多条结果的时候使用)
--declare cursor cursorname is 查询语句;
--打开游标
--open cursorname
--获取游标的值（提取数据）
--fetch cursorname into  v_name,v_salay
--关闭游标
--close cursorname

--%ISOPEN 判断游标是否打开
--%FOUND 有记录返回true
--%NOTFOUND 没有记录返回true
--%rowcount 行数

--获取所有员工的姓名和工资
declare
        cursor emp_namesal
        is
        select last_name,salary from employees;
     v_name employees.last_name%type;
     v_sal employees.salary%type;
     begin
       if not emp_namesal %isopen
         then
           open emp_namesal;
       end if;
       loop
           fetch emp_namesal into
           v_name,v_sal;
           exit when  emp_namesal%NOTFOUND;
           DBMS_OUTPUT.put_line(v_name||':'||v_sal);
       end loop;
        DBMS_OUTPUT.put_line('数据获取结束');
        close emp_namesal;
       end;

--更改数据
declare
        cursor emp_name
        is
        select last_name,salary from employees
        for update of salary;
     begin
       for emp_record in emp_name
         loop
           if emp_record.salary<1000
             then
              update employees set salary=salary+500
              where current of emp_name;
            end if;
        -- DBMS_OUTPUT.put_line('更改之前:'||v_salary);
        -- DBMS_OUTPUT.put_line(emp_record.last_name||':'||emp_record.salary);
        end loop;
       end;


--参数游标
--参数游标是指具体带有参数的游标。
--在定义了参数游标之后，当使用不同参数值多次打开游标时
--会获取不同的结果
declare
     cursor emp_cursor(cuo int)
   is
     select last_name,salary
            from employees
            where DEPARTMENT_ID=cuo;
     v_name employees.last_name%type;
     v_sal employees.salary%type;
   begin
     if not emp_cursor %isopen then
       open emp_cursor(2);
       end if;
     loop
        fetch emp_cursor into
        v_name,v_sal;
        exit when emp_cursor%NOTFOUND;
        DBMS_OUTPUT.put_line(v_name||':'||v_sal);
     end loop;
     DBMS_OUTPUT.put_line('输出结束');
     close emp_cursor;
     end;

--存储过程联合游标一起使用
create or replace procedure testout
(dep_id int)
is
    cursor emp_namesal(depid int)
    is
    select last_name,salary from employees
           where DEPARTMENT_ID=depid;
    v_name employees.last_name%type;
    v_sal employees.salary%type;
begin
    if not emp_namesal %isopen
         then
           open emp_namesal(dep_id);
       end if;
       loop
           fetch emp_namesal into
           v_name,v_sal;
           exit when  emp_namesal%NOTFOUND;
           DBMS_OUTPUT.put_line(v_name||':'||v_sal);
       end loop;
        DBMS_OUTPUT.put_line('数据获取结束');
        close emp_namesal;
  end;
 
--输入部门
--如果部门为3 部门下的员工增加 10%的工资
--如果部门为2 部门下的员工增加 20%的工资
--如果部门为1 部门下的员工增加 30%的工资
--如果没有该部门 则显示  ‘该部门不存在’
create or replace procedure dep_inPutId
(dep_id int)
   is
   --游标在什么时候使用： 查询多条语句的时候使用
   cursor emp_depid(depno int)
      is
     select * from employees where employees.department_id=depno;
     begin
        case dep_id
            when 1
              then
              update employees set salary=salary+salary*0.3
               where department_id=dep_id;
            when 2
              then
              update employees set salary=salary+salary*0.2
               where department_id=dep_id;
            when 3
              then
              update employees set salary=salary+salary*0.2
               where department_id=dep_id;
            else
              DBMS_OUTPUT.put_line('部门不存在!');
            end case;
            for empinfo in emp_depid(dep_id)
              loop
                DBMS_OUTPUT.put_line(empinfo.last_name||':'||empinfo.salary);
               end loop;
       end;

select * from employees
begin
  dep_inPutId(5);
  end;
 
 
--更改数据 与 之前的数据进行对比
create or replace procedure testEMP
    is
        cursor emp_name
        is
        select department_id,salary from employees
        for update of salary;
         v_depid employees.department_id%type;
         v_sal employees.salary%type;
     begin
       if not emp_name %isopen
         then
           open emp_name;
       end if;
       loop
           fetch emp_name into
           v_depid,v_sal;
           exit when  emp_name%NOTFOUND;
           DBMS_OUTPUT.put_line('旧:'||v_depid||':'||v_sal);
           case v_depid
            when 1
              then
              update employees set salary=salary+salary*0.3
               where current of emp_name;
            when 2
              then
              update employees set salary=salary+salary*0.2
               where current of emp_name;
            when 3
              then
              update employees set salary=salary+salary*0.2
               where current of emp_name;
            else
              DBMS_OUTPUT.put_line('部门不存在!');
            end case;
       end loop;
       close emp_name;
       for emp_record in emp_name
         loop
           DBMS_OUTPUT.put_line(emp_record.department_id||':'||emp_record.salary);
         end loop;
end;

begin
  testEMP;
  end;