我不喜欢这个主意…

drop procedure if exists dump_image;
delimiter //
  create procedure dump_image()
  begin

    declare this_id int;
    declare cur1 cursor for select imageId from image;
    open cur1;
      read_loop: loop
        fetch cur1 into this_id;
        set @query = concat('select blob_field from image where imageId=', 
            this_id, ' into outfile "/tmp/xyz-', this_id,'.jpg"');
        prepare write_file from @query;
        execute write_file;
      end loop;
    close cur1;
  end //
delimiter ;

尽管有错误

mysql>调用dump_image（）;
错误1329（02000）：无数据-提取，选择或处理了零行



ls -1 / tmp / xyz *