MySQLテーブルのデフォルトのソートに関する質問

  mysql     ：
     myisam ：
SELECT * FROM tbl -- this will do a "table scan". If the table has never had any DELETEs/REPLACEs/UPDATEs, the records will happen to be in the insertion order, hence what you observed. 
     ，  myisam           ，     ，   select   order by，             。

If you had done the same statement with an InnoDB table, they would have been delivered in PRIMARY KEY order, not INSERT order. Again, this is an artifact of the underlying implementation, not something to depend on.
  innodb     ，       ，select   order by，        ，    

 
  
【 】：                     。