背景：
导出数据库test库的test表数据出现报错信息：mysqldump: [ERROR] unknown variable 'database=test'.
原来是my.cnf参数文件配置了以下内容：
[client]
user=test
port=3306
database=test
将database参数注释掉，就不再出现报错。
[root@node01 tmp]# mysqldump -utest -pmysql test test > /tmp/ttt.sql
mysqldump: [Warning] Using a password on the command line interface can be insecure.
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.
