mysqlselect的有关问题

mysql> select * from u01;

+----+-----+------+

| id | num | data |

+----+-----+------+

|  1 |  12 |   13 |

|  2 |  13 |   14 |

|  3 |  15 |   14 |

|  4 |  16 |   14 |

|  5 |  17 |   13 |

+----+-----+------+

5 rows in set (0.00 sec)