仅使用SQL将Blob从MySQL数据库导出到文件

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 *