PL / SQL Example 1

DECLARE
- define a cursor
   Cursor CEMP IS SELECT TO_CHAR (HireDate, 'YYYY') from EMP;
    phiredate VARCHAR2 (. 4);
   - the annual number entry defines
    count80 Number: = 0;
    count81 Number: = 0;
    count82 Number: = 0 ;
    count87 Number: = 0;
   the begin
      - open cursor
     open CEMP;
      - cyclic
     loop
       - taking a year employee entry
       fETCH iNTO phiredate CEMP;
       - defined circulation outlet
        exit When CEMP% NOTFOUND;
        --IF determining
        if phiredate = '1980' the then count80: + = count80. 1;
        ELSIF phiredate = '1981' the then count81: + = count81. 1;
        ELSIF phiredate = '1982' the then count82: + = count82. 1;
        the else count87: + = count87. 1;
        end if;

--结束循环
      end loop;
      --关闭游标
      close cemp;
      --输出
       dbms_output.put_line('total:'||(count80+count81+count82+count87));
       dbms_output.put_line('1980:'||count80);
       dbms_output.put_line('1981:'||count81);
       dbms_output.put_line('1982:'||count82);
       dbms_output.put_line('1987:'||count87);
      end;