[root@bigdata ~]# whereis mysql
mysql: /usr/bin/mysql /usr/lib64/mysql /usr/share/mysql /usr/share/man/man1/mysql.1.gz
[root@bigdata ~]# which mysql
/bin/mysql
[root@bigdata ~]# rpm -qa | grep -i mysql
mysql-community-libs-compat-5.7.20-1.el7.x86_64
mysql-community-common-5.7.20-1.el7.x86_64
mysql-community-server-5.7.20-1.el7.x86_64
mysql57-community-release-el7-11.noarch
mysql-community-libs-5.7.20-1.el7.x86_64
mysql-community-client-5.7.20-1.el7.x86_64
[root@bigdata ~]#

[root@bigdata ~]# systemctl list-unit-files | grep -i mysql
mysqld.service                                enabled
mysqld@.service                               disabled
[root@bigdata ~]#
[root@bigdata ~]# mysql -uroot -pMyNewPass4!
[root@bigdata ~]# ps -el | grep mysqld
1 S    27   1317      1  0  80   0 - 281955 poll_s ?       00:00:02 mysqld
[root@bigdata ~]#
[root@bigdata ~]# mysql --help | grep 'Default options' -A 1
Default options are read from the following files in the given order:
/etc/my.cnf /etc/mysql/my.cnf /usr/etc/my.cnf ~/.my.cnf
[root@bigdata ~]#

[root@bigdata ~]# locate my.cnf
/etc/my.cnf
/etc/my.cnf.d
/etc/my.cnf.d/mysql-clients.cnf
[root@bigdata ~]#
[root@bigdata ~]# yum list installed | grep mysql
mysql-community-client.x86_64          5.7.20-1.el7                    @mysql57-community
mysql-community-common.x86_64          5.7.20-1.el7                    @mysql57-community
mysql-community-libs.x86_64            5.7.20-1.el7                    @mysql57-community
mysql-community-libs-compat.x86_64     5.7.20-1.el7                    @mysql57-community
mysql-community-server.x86_64          5.7.20-1.el7                    @mysql57-community
mysql57-community-release.noarch       el7-11                          installed
[root@bigdata ~]#
[root@bigdata ~]# yum list installed | grep mysql
mysql-community-client.x86_64          5.7.20-1.el7                    @mysql57-community
mysql-community-common.x86_64          5.7.20-1.el7                    @mysql57-community
mysql-community-libs.x86_64            5.7.20-1.el7                    @mysql57-community
mysql-community-libs-compat.x86_64     5.7.20-1.el7                    @mysql57-community
mysql-community-server.x86_64          5.7.20-1.el7                    @mysql57-community
mysql57-community-release.noarch       el7-11                          installed
[root@bigdata ~]# yum repolist enabled | grep "mysql.*-community.*"
!mysql-connectors-community/x86_64 MySQL Connectors Community                42
!mysql-tools-community/x86_64      MySQL Tools Community                     55
!mysql57-community/x86_64          MySQL 5.7 Community Server               227
检查mysql源是否安装成功
[root@bigdata ~]# yum -y list mysql*
查看yum库上的mysql版本信息
[root@bigdata ~]# yum list | grep mysql

[root@bigdata ~]# mysqldump -h127.0.0.1 -uroot -pMyNewPass4! test > backupfile.sql
mysqldump: [Warning] Using a password on the command line interface can be insecure.


[mysqldump]
user=root
password=MyNewPass4!


mysqldump -h127.0.0.1 test > backupfile.sql
mysql -h127.0.0.1 -uroot -pMyNewPass4! test < backupfile.sql

mysql> show global variables like "%datadir%";
+---------------+-----------------+
| Variable_name | Value           |
+---------------+-----------------+
| datadir       | /var/lib/mysql/ |
+---------------+-----------------+
1 row in set (0.00 sec)

mysql> show global variables
mysql> show session variables
mysql> show variables like 'wait_timeout';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| wait_timeout  | 28800 |
+---------------+-------+
1 row in set (0.00 sec)

mysql> show variables like '%timeout%';
+-----------------------------+----------+
| Variable_name               | Value    |
+-----------------------------+----------+
| connect_timeout             | 10       |
| delayed_insert_timeout      | 300      |
| have_statement_timeout      | YES      |
| innodb_flush_log_at_timeout | 1        |
| innodb_lock_wait_timeout    | 50       |
| innodb_rollback_on_timeout  | OFF      |
| interactive_timeout         | 28800    |
| lock_wait_timeout           | 31536000 |
| net_read_timeout            | 30       |
| net_write_timeout           | 60       |
| rpl_stop_slave_timeout      | 31536000 |
| slave_net_timeout           | 60       |
| wait_timeout                | 28800    |
+-----------------------------+----------+
13 rows in set (0.00 sec)

mysql>

导出数据和表结构
mysqldump test > test.sql

导入数据库
mysql -uroot -pMyNewPass4! test < test.sql


只导出表结构
mysqldump -d test > test.sql
导入数据库
mysql -uroot -pMyNewPass4! test < test.sql


只导出数据
mysql> SHOW VARIABLES LIKE "secure_file_priv";
+------------------+-----------------------+
| Variable_name    | Value                 |
+------------------+-----------------------+
| secure_file_priv | /var/lib/mysql-files/ |
+------------------+-----------------------+
1 row in set (0.00 sec)

mysql> SELECT * FROM tb_name INTO OUTFILE '/var/lib/mysql-files/tb_name.txt';
Query OK, 3 rows affected (0.00 sec)

mysql> SELECT * FROM tb_name INTO OUTFILE '/var/lib/mysql-files/tb_name1.txt' FIELDS TERMINATED BY ',' ENCLOSED BY '"' LINES TERMINATED BY '\r\n';
Query OK, 3 rows affected (0.00 sec)

mysql> SELECT id,name,name || 'test' INTO OUTFILE '/var/lib/mysql-files/test.txt' FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"' LINES TERMINATED BY '\n' FROM tb_name;
Query OK, 3 rows affected (0.00 sec)


将数据表 tb_name 导出到 /var/lib/mysql-files 目录中：
$ mysqldump -uroot -pMyNewPass4! --no-create-info --tab=/var/lib/mysql-files test tb_name
            
导出SQL格式的数据到指定文件            
$ mysqldump -uroot -pMyNewPass4! test tb_name > dump.txt
            
导出整个数据库的数据
$ mysqldump -uroot -pMyNewPass4! test > database_dump.txt

备份所有数据库
$ mysqldump -uroot -pMyNewPass4! --all-databases > database_dump.txt

使用了管道来将导出的数据导入到指定的远程主机上

$ mysqldump -u root -p database_name | mysql -h other-host.com database_name