select * from a
select * from b
declare Mycursor CURSOR
for select * from b
open Mycursor
declare @stuID nchar(10)
declare @math smallint
fetch next from Mycursor
into @stuID,@math
while(@@FETCH_STATUS = 0)
begin
update a set math = @math where stuID = @stuID
fetch next from Mycursor
into @stuID,@math
end
close Mycursor
