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  • having在Oracle和mysql小点不同

        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 Settingsguogang>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)

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  • 原文地址:https://www.cnblogs.com/mengfanrong/p/4556052.html
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