根据现有数据库值，循环拼接SQL语句

declare @sql varchar(max)DECLARE @id int  declare @f5 varchar(50)DECLARE vend_cursor CURSOR  FOR select id,field_5 from hpclassOPEN vend_cursor  FETCH NEXT FROM vend_cursor into @id,@f5;            set @sql=''WHILE(@@fetch_status=0)  BEGIN  set @sql +='update hpclass set field_5='''+@f5+''' where id='+cast(@id as varchar(10))+';';  FETCH NEXT FROM vend_cursor into @id,@f5;  END  close vend_cursor   --关闭游标  deallocate vend_cursor  print @sql