使用oralce Cursor

发布: 2007-7-02 11:08 | 作者: admin | 来源: | 查看: 9次 | 进入软件测试论坛讨论

使用Cursor:
declare

RoomID       Room.RoomID%Type;

RoomName     Room.RoomName%Type;

cursor crRoom is

select RoomID,RoomName

     from Room;

begin

open crRoom;

loop;

fetch crRoom into RoomID,RoomName;

exit when crRoom%notFound;

end loop;

close crRoom;

end;

3.1在游标使用入口参数
在SQL语句的Where 子句中恰当使用相关语句简化逻辑，本来需要使用两个游标，把相关入口参数放入到SQL语句的Where 子句中，一个就搞定了：

cursor    crRoom    is
      select
        distinct 楼层,房屋用途
        from      TT_没有处理的房屋 t
        where     数据级别>= 0
            and   房屋处理类别= 3
            and   产权编号=p_产权编号
            and   拆迁房屋类别=p_拆迁房屋类别
            and   面积>0
            and   (not p_房屋用途 is null
                   and 房屋用途=p_房屋用途
                   or p_房屋用途 is null);

另外一个例子：

CREATE OR REPLACE PROCEDURE PrintStudents(
p_Major IN students.major%TYPE) AS
CURSOR c_Students IS
    SELECT first_name, last_name
      FROM students
      WHERE major = p_Major;
BEGIN
FOR v_StudentRec IN c_Students LOOP
    DBMS_OUTPUT.PUT_LINE(v_StudentRec.first_name || @# @# ||
                         v_StudentRec.last_name);
END LOOP;
END;

Oracle带的例子examp6.sql

DECLARE
    CURSOR bin_cur(part_number NUMBER) IS SELECT amt_in_bin
        FROM bins
        WHERE part_num = part_number AND
            amt_in_bin > 0
            ORDER BY bin_num
            FOR UPDATE OF amt_in_bin;
    bin_amt         bins.amt_in_bin%TYPE;
    total_so_far    NUMBER(5) := 0;
    amount_needed   CONSTANT NUMBER(5) := 1000;
    bins_looked_at NUMBER(3) := 0;
BEGIN
    OPEN bin_cur(5469);
    WHILE total_so_far < amount_needed LOOP
        FETCH bin_cur INTO bin_amt;
        EXIT WHEN bin_cur%NOTFOUND;
             /* If we exit, there@#s not enough to *
              * satisfy the order.                */
        bins_looked_at := bins_looked_at + 1;
        IF total_so_far + bin_amt < amount_needed THEN
            UPDATE bins SET amt_in_bin = 0
                WHERE CURRENT OF bin_cur;
                    -- take everything in the bin
            total_so_far := total_so_far + bin_amt;
        ELSE        -- we finally have enough
            UPDATE bins SET amt_in_bin = amt_in_bin
                - (amount_needed - total_so_far)
                WHERE CURRENT OF bin_cur;
            total_so_far := amount_needed;
        END IF;
    END LOOP;
    CLOSE bin_cur;
    INSERT INTO temp VALUES (NULL, bins_looked_at, @#<- bins looked at@#);
    COMMIT;
END;

-- Created on 2004-8-9 by ADMINISTRATOR
declare
--带有变量的Cursor
cursor crBooks(c_bookTitle varchar2) is
     select *
       from books a
       where a.title like c_bookTitle||@#%@#;
begin
for v_Books in crBooks(@#Oracle8@#) loop
    dbms_output.put_line(v_Books.author1);
end loop;
end;