mysql使用游标遍历数据进行批量针对性更新数据，急求mysql大神解答

根据你的资料，正确的答案应该如下：望采纳

CREATE DEFINER=`root`@`localhost` PROCEDURE `P_updateUd18`(`Param` int(11))

BEGIN

declare Rcount,i,j,k,Rparentid,myId int(11) default 0

declare Robjname,Robjname23,Robjname45,Robjname67,Robjname89 varchar(9) default ""

select count(id) into Rcount from ud18

repeat

select id,objname into myId,Robjname from ud18 order by id limit i,1

set Robjname23=SUBSTRING(Robjname,2,2)

set Robjname45=SUBSTRING(Robjname,4,2)

set Robjname67=SUBSTRING(Robjname,6,2)

set Robjname89=SUBSTRING(Robjname,8,2)

if Robjname89>0 then

set @sql=concat("select id into @abc from ud18 where objname like '",left(Robjname,7),"00","'")

prepare stmt from @sql

EXECUTE stmt

set Rparentid=@abc

update ud18 set parentid=Rparentid where id=myId

elseif Robjname67>0 then

set @sql=concat("select id into @abc from ud18 where objname like '",left(Robjname,5),"0000","'")

prepare stmt from @sql

EXECUTE stmt

set Rparentid=@abc

update ud18 set parentid=Rparentid where id=myId

elseif Robjname45>0 then

set @sql=concat("select id into @abc from ud18 where objname like '",left(Robjname,3),"000000","'")

prepare stmt from @sql

EXECUTE stmt

set Rparentid=@abc

update ud18 set parentid=Rparentid where id=myId

elseif Robjname23>0 then

-- set @sql=concat("select id into @abc from ud18 where objname like '",left(Robjname,1),"00000000","'")

-- prepare stmt from @sql

-- EXECUTE stmt

-- set Rparentid=@abc

update ud18 set parentid=0 where id=myId

else

set j=0

end if

set i=i+1

until i>Rcount end repeat

END

3个 UPDATE比开游标划算:

举其中一种情况的例子:

UPDATE BBB 

   SET BBB.DIQUHAO = (SELECT ABB.DIQUHAO FROM ABB WHERE ABB.ID = BBB.ID)

 WHERE EXISTS(SELECT 1 

                FROM ABB 

   WHERE BBB.ID = ABB.ID  

                 AND ABB.XINGMING = BBB.XINGMING 

                 AND ABB.YIBAOHAO = BBB.YIBAOHAO)

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