在Oracle中，having一定要结合group by使用，但在mysql中，情况就不一样了。能够单独使用。

C:\Documents and Settings\guogang>sqlplus test/test

SQL*Plus: Release 10.2.0.1.0 - Production on 星期二 8月 12 09:09:58 2014

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

连接到:

Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production

With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL> select * from test1  having owner ='SYS';

select * from test1  having owner ='SYS'

                         *

第 1 行出现错误:

ORA-00979: 不是 GROUP BY 表达式

SQL> select owner,count(1) from test1  group by owner having owner ='SYS';

OWNER                            COUNT(1)

------------------------------ ----------

SYS                                 30754

mysql> select * from test having id>98;

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

| id   | create_time |

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

|   99 | 2014-08-12  |

|  100 | 2014-08-12  |

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

2 rows in set (0.00 sec)

mysql> select id,count(1) from test group by id having id>98;

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

| id   | count(1) |

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

|   99 |        1 |

|  100 |        1 |

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

2 rows in set (0.00 sec)