MySQL循环查询语句 有关

create procedure pp1(in id int)
begin
declare I int;
declare j int;
declare k int;
declare a int;
declare b varchar(300);
set k=0;
set I=1;
set j=9;
while j<(select length(member_list) from t where user_id=id)
set a=(select card from t,x where t.id=x.id and user_id=id and car=substr(member_list,I,j);
set k=k+1;
if k=3 then
set I=I+11;
set j=j+11;
else
set I=I+10;
set j=j+10;
end if
b=b+a;
end while
select b;
end

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