mysql 游标中可以嵌套游标吗

CREATE PROCEDURE SumOfStu(OUT Sdeptno int,OUT Sdeptname char(20),OUT sumBefore int,OUT sumAfter int)

BEGIN

DECLARE l_sum int

DECLARE l_Sdeptno int

DECLARE l_sno int

DECLARE l_sumBefore int

DECLARE done, done2 INT DEFAULT 0

DECLARE cur_out cursor for select SdeptNo,population from Department

DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1

OPEN cur_out

REPEAT

SET l_sum=0

FETCH cur_out INTO l_Sdeptno,l_sumBefore

IF NOT done THEN

BEGIN

DECLARE cur_inner cursor for select Sno from student where SdeptNo=l_Sdeptno

DECLARE CONTINUE HANDLER FOR NOT FOUND SET done2 = 1

OPEN cur_inner

REPEAT

FETCH cur_inner into l_sno

IF NOT done2 THEN

SET ps_count = 0

SET l_sum=l_sum+1

END IF

UNTIL done2

END REPEAT

CLOSE cur_inner

SET done2 = 0

END

IF(l_sum<>l_sumBefore) THEN

update department SET population=l_sum where SdeptNo=l_Sdeptno

select l_Sdeptno INTO Sdeptno

select SdeptName INTO Sdeptname from Department where SdeptNo=l_Sdeptno

select l_sumBefore INTO sumBefore

select l_sum INTO sumAfter

end IF

END IF

UNTIL done

END REPEAT

CLOSE cur_out

END

是游标里面嵌套游标吗？数据量大的话最好不要采用这种方法！

这是SQL SERVER的：

DECLARE CUR_1 CURSOR--第一层游标声明

FOR SELECT C_1,C_2 FROM TABLENAME

OPEN CUR_1

FETCH NEXT FROM CUR_1 INTO @C_1,@C_2

WHILE @@FETCH_STATUES<>0

BEGIN

DECLARE CUR_2 CURSOR--第二层游标声明

FOR SELECT A_1,A_2 FROM TABLENAME

OPEN CUR_2

FETCH NEXT FROM CUR_2 INTO @C_1,@C_2

WHILE @@FETCH_STATUES<>0

BEGIN

.....

.....

FETCH NEXT FROM CUR_2 INTO @A_1,@A_2--二层循环

END

CLOSE CUR_2

DEALLOCATE CUR_2

FETCH NEXT FROM CUR_1 INTO @C_1,@C_2--一层循环

END

CLOSE CUR_1

DEALLOCATE CUR_1

要其他数据库的游标找我。

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