Having has some differences in Oracle and mysql

Having has some differences in Oracle and mysql

In Oracle, having must be used in combination with group by, but in mysql, the situation is different and can be used separately.

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

SQL * Plus: Release 10.2.0.1.0-Production on Tuesday August 12 09:09:58 2014
Copyright (c) 1982,200 5, Oracle. All rights reserved.
Connect:
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'
*
Row 3 has an error:

ORA-00979: Not a group by expression

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 |
+ ------ + ------------- +
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 |
| 1 | 100 |
+ ------ + ---------- +
2 rows in set (0.00 sec)