Mysqldump 数据导出问题和客户端授权后连接失败问题
1，使用mysqldump时报错(1064)，这个是因为mysqldump版本太低与当前数据库版本不一致导致的。
mysqldump: Couldn't execute 'SET OPTION SQL_QUOTE_SHOW_CREATE=1': You have an error in your SQL syntax; check the manual that
corresponds to your MySQL server version for the right syntax to use near 'OPTION SQL_QUOTE_SHOW_CREATE=1' at line 1 (1064)
[root@bastion-IDC ~]# mysqldump --version
mysqldump Ver 10.13 Distrib 5.1.61, for redhat-linux-gnu (x86_64)
[root@bastion-IDC ~]# mysql //或者登陆mysql，select version();也可查看版本
Server version: 5.6.25-log Source distribution
.........
这样的话必须知道mysqldump的绝对路径，在mysql的安装目录下有。
2，导出时指定字符集，报错
Character set 'utf-8' is not a compiled character set and is not specifie .
--default-character-set=utf-8
这个是因为字符集错了。是--default-character-set=utf8
3，导出时提示warning，A partial dump from a server that has GTIDs
[root@bastion-IDC ~]# mysqldump -uroot -p xqsj_db > xqsj_db20160811.sql
Warning: A partial dump from a server that has GTIDs will by default include the GTIDs of all transactions, even those that
changed suppressed parts of the database. If you don't want to restore GTIDs, pass --set-gtid-purged=OFF. To make a complete
dump, pass --all-databases --triggers --routines --events.
关于GTID是5.6以后，加入了全局事务 ID (GTID) 来强化数据库的主备一致性，故障恢复，以及容错能力。
官方给的：A global transaction identifier (GTID) is a unique identifier created and associated with each transaction committed on the server of origin (master).
所以可能是因为在一个数据库里面唯一，但是当导入其他的库就有可能重复。所有会有一个提醒。
可以通过添加--set-gtid-purged=off 或者–gtid-mode=OFF这两个参数设置。
很有肯能是在导入库中重新生产GTID，而不用原来的。
[root@bastion-IDC ~]# mysqldump -uroot --set-gtid-purged=off -p xqsj_db > xqsj_db20160811.sql #这样就ok了！
---------------------------------------------------------------------------------------------------------
在本地（192.168.1.152）部署好mysql环境，授权远程客户机192.168.1.%连接本机的mysql，在iptables防火墙也已开通3306端口。
如下：
mysql> select host,user,password from mysql.user; +--------------+-----------------+----------------------------------------------------------+ | host | user | password | +--------------+-----------------+----------------------------------------------------------+ | localhost | root | | | fdm1 | root | | | 127.0.0.1 | root | | | localhost | | | | fdm1 | | | | 192.168.1.% | db_hqsb | *DFC9DC16B13651A95ECEC3A26E07D244431B55C9 | | 192.168.1.% | db_ro_hqsb | *2C0B0DD50595BB40879110437BEEF026D019DFB7 | | 192.168.1.% | db_jkhwuser | *2C0B0DD50595BB40879110437BEEF026D019DFB7 | | 192.168.1.25 | slave | *EE52B8EACB3CCD13624273AD6B5CDA52B9B53EB7 | | 192.168.1.% | tech_db_user | *6053E57C7B61043DC2C6B4E3291D5F61CCC23F5C | | 192.168.1.% | game_db_user | *05EA4D71C9A1273ECF3E24E6323F7175AE45C366 | | localhost | zabbix | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 | +---------------+---------------+-----------------------------------------------------------+
问题：
在客户机（比如192.168.1.20）上远程连接上面192.168.1.152机器的mysql，连接失败！
[root@huanqiu ~]# mysql -udb_ro_hqsb -h 192.168.1.152 -pmhxzkhl0802xqsjdb
ERROR 1130 (HY000): Host '192.168.1.20' is not allowed to connect to this MySQL server
解决：
是由于192.168.1.152的mysql里“host为localhost，user和password为空”这条语句导致的，删除这条即可解决问题！
mysql> delete from mysql.user where host="localhost" and user="";
Query OK, 1 row affected (0.00 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
这样，授权连接的客户机就能成功连接了！
[root@huanqiu ~]# mysql -uxqsj_db_ro_user -h 192.168.1.152 -pmhxzkhl0802xqsjdb
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 28
Server version: 5.1.73 Source distribution
Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>
