CentOS下Mysql简易操作
Mysql
mysql的root密码重置
编辑mysql主配置文件
vim /etc/my.cnf
添加..grant参数
[mysqld]
skip-grant
重启mysql服务
service mysqld restart
进入数据库不用授权
更新root用户密码
/usr/local/mysql/bin/mysql -uroot
use mysql;
update user set password=password('mysql1234') where user='root';
flush privileges;
quit;
注释添加的...grant参数
vim /etc/my.cnf
重启mysql服务
service mysqld restart
重新用新密码登录
/usr/local/mysql/bin/mysql -uroot -pmysql1234
mysql登录
-u用户
-p密码
-h主机
-P端口
-S套接字
默认Mysql的root用户密码为空，登录不用加-p选项
/usr/local/mysql/bin/mysql -uroot -h 127.0.0.1
设置一个密码
/usr/local/mysql/bin/mysqladmin -uroot password 'mysql1234'
再次登录
/usr/local/mysql/bin/mysql -u root -pmysql1234 -h 127.0.0.1
套结字本地登录
/usr/local/mysql/bin/mysql -uroot -S /tmp/mysql.sock -pmysql1234
再设置一个密码就需要输入之前的密码
/usr/local/mysql/bin/mysqladmin -uroot -pmysql1234 password 'mysql12345' -h 127.0.0.1
设置别名
[root@localhost ~]# vim /etc/bashrc
alias mysql=/usr/local/mysql/bin/mysql
alias mysqladmin=/usr/local/mysql/bin/mysqladmin
更改PATH
[root@localhost ~]# vim /etc/profile.d/path.sh
export PATH=$PATH:/usr/local/mysql/bin
[root@localhost ~]# source /etc/profile.d/path.sh
mysql常用操作
查看都有哪些库
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| discuz |
| mysql |
| test |
+--------------------+
4 rows in set (0.00 sec)
查看某个库的表
mysql> use information_schema;show tables;
Database changed
+---------------------------------------+
| Tables_in_information_schema |
+---------------------------------------+
| CHARACTER_SETS |
| COLLATIONS |
| COLLATION_CHARACTER_SET_APPLICABILITY |
| COLUMNS |
| COLUMN_PRIVILEGES |
| ENGINES |
| EVENTS |
| FILES |
| GLOBAL_STATUS |
| GLOBAL_VARIABLES |
| KEY_COLUMN_USAGE |
| PARTITIONS |
| PLUGINS |
| PROCESSLIST |
| PROFILING |
| REFERENTIAL_CONSTRAINTS |
| ROUTINES |
| SCHEMATA |
| SCHEMA_PRIVILEGES |
| SESSION_STATUS |
| SESSION_VARIABLES |
| STATISTICS |
| TABLES |
| TABLE_CONSTRAINTS |
| TABLE_PRIVILEGES |
| TRIGGERS |
| USER_PRIVILEGES |
| VIEWS |
+---------------------------------------+
28 rows in set (0.00 sec)
查看表的字段类型
mysql> desc VIEWS;
+----------------------+--------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------------------+--------------+------+-----+---------+-------+
| TABLE_CATALOG | varchar(512) | YES | | NULL | |
| TABLE_SCHEMA | varchar(64) | NO | | | |
| TABLE_NAME | varchar(64) | NO | | | |
| VIEW_DEFINITION | longtext | NO | | NULL | |
| CHECK_OPTION | varchar(8) | NO | | | |
| IS_UPDATABLE | varchar(3) | NO | | | |
| DEFINER | varchar(77) | NO | | | |
| SECURITY_TYPE | varchar(7) | NO | | | |
| CHARACTER_SET_CLIENT | varchar(32) | NO | | | |
| COLLATION_CONNECTION | varchar(32) | NO | | | |
+----------------------+--------------+------+-----+---------+-------+
10 rows in set (0.00 sec)
查看创建表的语句
mysql> show create table VIEWS;
+-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| VIEWS | CREATE TEMPORARY TABLE `VIEWS` (
`TABLE_CATALOG` varchar(512) DEFAULT NULL,
`TABLE_SCHEMA` varchar(64) NOT NULL DEFAULT '',
`TABLE_NAME` varchar(64) NOT NULL DEFAULT '',
`VIEW_DEFINITION` longtext NOT NULL,
`CHECK_OPTION` varchar(8) NOT NULL DEFAULT '',
`IS_UPDATABLE` varchar(3) NOT NULL DEFAULT '',
`DEFINER` varchar(77) NOT NULL DEFAULT '',
`SECURITY_TYPE` varchar(7) NOT NULL DEFAULT '',
`CHARACTER_SET_CLIENT` varchar(32) NOT NULL DEFAULT '',
`COLLATION_CONNECTION` varchar(32) NOT NULL DEFAULT ''
) ENGINE=MyISAM DEFAULT CHARSET=utf8 |
+-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
查看创建库的语句
mysql> show create database information_schema;
+--------------------+-----------------------------------------------------------------------------+
| Database | Create Database |
+--------------------+-----------------------------------------------------------------------------+
| information_schema | CREATE DATABASE `information_schema` /*!40100 DEFAULT CHARACTER SET utf8 */ |
+--------------------+-----------------------------------------------------------------------------+
1 row in set (0.00 sec)
查看当前是哪个用户
mysql> select user();
+----------------+
| user() |
+----------------+
| root@localhost |
+----------------+
1 row in set (0.00 sec)
查看当前库
mysql> select database();
+--------------------+
| database() |
+--------------------+
| information_schema |
+--------------------+
1 row in set (0.00 sec)
创建一个库
mysql> create database db1;
Query OK, 1 row affected (0.00 sec)
指定使用某个库
mysql> use db1;
Database changed
创建某个表
mysql> create table t1(`id` int(4),`name` char(40));
Query OK, 0 rows affected (0.05 sec)
插入数据
mysql> insert into t1(id,name) values (1,'gyt');
Query OK, 1 row affected (0.00 sec)
查询表内容
mysql> select * from t1;
+------+------+
| id | name |
+------+------+
| 1 | gyt |
+------+------+
1 row in set (0.00 sec)
查看数据库版本
mysql> select version();
+------------+
| version() |
+------------+
| 5.1.73-log |
+------------+
1 row in set (0.00 sec)
查看mysql状态
mysql> show status;
+-----------------------------------+----------+
| Variable_name | Value |
+-----------------------------------+----------+
| Aborted_clients | 0 |
| Aborted_connects | 3 |
| Binlog_cache_disk_use | 0 |
| Binlog_cache_use | 0 |
| Bytes_received | 870 |
| Bytes_sent | 12055 |
| Com_admin_commands | 0 |
| Com_assign_to_keycache | 0 |
| Com_alter_db | 0 |
| Com_alter_db_upgrade | 0 |
| Com_alter_event | 0 |
| Com_alter_function | 0 |
| Com_alter_procedure | 0 |
| Com_alter_server | 0 |
| Com_alter_table | 0 |
| Com_alter_tablespace | 0 |
| Com_analyze | 0 |
| Com_backup_table | 0 |
| Com_begin | 0 |
| Com_binlog | 0 |
| Com_call_procedure | 0 |
| Com_change_db | 3 |
| Com_change_master | 0 |
| Com_check | 0 |
| Com_checksum | 0 |
| Com_commit | 0 |
| Com_create_db | 1 |
| Com_create_event | 0 |
| Com_create_function | 0 |
| Com_create_index | 0 |
| Com_create_procedure | 0 |
| Com_create_server | 0 |
| Com_create_table | 1 |
| Com_create_trigger | 0 |
| Com_create_udf | 0 |
| Com_create_user | 0 |
| Com_create_view | 0 |
| Com_dealloc_sql | 0 |
| Com_delete | 0 |
| Com_delete_multi | 0 |
| Com_do | 0 |
| Com_drop_db | 0 |
| Com_drop_event | 0 |
| Com_drop_function | 0 |
| Com_drop_index | 0 |
| Com_drop_procedure | 0 |
| Com_drop_server | 0 |
| Com_drop_table | 0 |
| Com_drop_trigger | 0 |
| Com_drop_user | 0 |
| Com_drop_view | 0 |
| Com_empty_query | 0 |
| Com_execute_sql | 0 |
| Com_flush | 0 |
| Com_grant | 0 |
| Com_ha_close | 0 |
| Com_ha_open | 0 |
| Com_ha_read | 0 |
| Com_help | 0 |
| Com_insert | 1 |
| Com_insert_select | 0 |
| Com_install_plugin | 0 |
| Com_kill | 0 |
| Com_load | 0 |
| Com_load_master_data | 0 |
| Com_load_master_table | 0 |
| Com_lock_tables | 0 |
| Com_optimize | 0 |
| Com_preload_keys | 0 |
| Com_prepare_sql | 0 |
| Com_purge | 0 |
| Com_purge_before_date | 0 |
| Com_release_savepoint | 0 |
| Com_rename_table | 0 |
| Com_rename_user | 0 |
| Com_repair | 0 |
| Com_replace | 0 |
| Com_replace_select | 0 |
| Com_reset | 0 |
| Com_restore_table | 0 |
| Com_revoke | 0 |
| Com_revoke_all | 0 |
| Com_rollback | 0 |
| Com_rollback_to_savepoint | 0 |
| Com_savepoint | 0 |
| Com_select | 9 |
| Com_set_option | 0 |
| Com_show_authors | 0 |
| Com_show_binlog_events | 0 |
| Com_show_binlogs | 0 |
| Com_show_charsets | 0 |
| Com_show_collations | 0 |
| Com_show_column_types | 0 |
| Com_show_contributors | 0 |
| Com_show_create_db | 2 |
| Com_show_create_event | 0 |
| Com_show_create_func | 0 |
| Com_show_create_proc | 0 |
| Com_show_create_table | 1 |
| Com_show_create_trigger | 0 |
| Com_show_databases | 2 |
| Com_show_engine_logs | 0 |
| Com_show_engine_mutex | 0 |
| Com_show_engine_status | 0 |
| Com_show_events | 0 |
| Com_show_errors | 0 |
| Com_show_fields | 2 |
| Com_show_function_status | 0 |
| Com_show_grants | 0 |
| Com_show_keys | 0 |
| Com_show_master_status | 0 |
| Com_show_new_master | 0 |
| Com_show_open_tables | 0 |
| Com_show_plugins | 0 |
| Com_show_privileges | 0 |
| Com_show_procedure_status | 0 |
| Com_show_processlist | 0 |
| Com_show_profile | 0 |
| Com_show_profiles | 0 |
| Com_show_slave_hosts | 0 |
| Com_show_slave_status | 0 |
| Com_show_status | 2 |
| Com_show_storage_engines | 0 |
| Com_show_table_status | 0 |
| Com_show_tables | 2 |
| Com_show_triggers | 0 |
| Com_show_variables | 0 |
| Com_show_warnings | 0 |
| Com_slave_start | 0 |
| Com_slave_stop | 0 |
| Com_stmt_close | 0 |
| Com_stmt_execute | 0 |
| Com_stmt_fetch | 0 |
| Com_stmt_prepare | 0 |
| Com_stmt_reprepare | 0 |
| Com_stmt_reset | 0 |
| Com_stmt_send_long_data | 0 |
| Com_truncate | 0 |
| Com_uninstall_plugin | 0 |
| Com_unlock_tables | 0 |
| Com_update | 0 |
| Com_update_multi | 0 |
| Com_xa_commit | 0 |
| Com_xa_end | 0 |
| Com_xa_prepare | 0 |
| Com_xa_recover | 0 |
| Com_xa_rollback | 0 |
| Com_xa_start | 0 |
| Compression | OFF |
| Connections | 6 |
| Created_tmp_disk_tables | 4 |
| Created_tmp_files | 5 |
| Created_tmp_tables | 8 |
| Delayed_errors | 0 |
| Delayed_insert_threads | 0 |
| Delayed_writes | 0 |
| Flush_commands | 1 |
| Handler_commit | 0 |
| Handler_delete | 0 |
| Handler_discover | 0 |
| Handler_prepare | 0 |
| Handler_read_first | 1 |
| Handler_read_key | 0 |
| Handler_read_next | 0 |
| Handler_read_prev | 0 |
| Handler_read_rnd | 0 |
| Handler_read_rnd_next | 55 |
| Handler_rollback | 0 |
| Handler_savepoint | 0 |
| Handler_savepoint_rollback | 0 |
| Handler_update | 0 |
| Handler_write | 49 |
| Innodb_buffer_pool_pages_data | 19 |
| Innodb_buffer_pool_pages_dirty | 0 |
| Innodb_buffer_pool_pages_flushed | 0 |
| Innodb_buffer_pool_pages_free | 493 |
| Innodb_buffer_pool_pages_misc | 0 |
| Innodb_buffer_pool_pages_total | 512 |
| Innodb_buffer_pool_read_ahead_rnd | 1 |
| Innodb_buffer_pool_read_ahead_seq | 0 |
| Innodb_buffer_pool_read_requests | 77 |
| Innodb_buffer_pool_reads | 12 |
| Innodb_buffer_pool_wait_free | 0 |
| Innodb_buffer_pool_write_requests | 0 |
| Innodb_data_fsyncs | 3 |
| Innodb_data_pending_fsyncs | 0 |
| Innodb_data_pending_reads | 0 |
| Innodb_data_pending_writes | 0 |
| Innodb_data_read | 2494464 |
| Innodb_data_reads | 25 |
| Innodb_data_writes | 3 |
| Innodb_data_written | 1536 |
| Innodb_dblwr_pages_written | 0 |
| Innodb_dblwr_writes | 0 |
| Innodb_log_waits | 0 |
| Innodb_log_write_requests | 0 |
| Innodb_log_writes | 1 |
| Innodb_os_log_fsyncs | 3 |
| Innodb_os_log_pending_fsyncs | 0 |
| Innodb_os_log_pending_writes | 0 |
| Innodb_os_log_written | 512 |
| Innodb_page_size | 16384 |
| Innodb_pages_created | 0 |
| Innodb_pages_read | 19 |
| Innodb_pages_written | 0 |
| Innodb_row_lock_current_waits | 0 |
| Innodb_row_lock_time | 0 |
| Innodb_row_lock_time_avg | 0 |
| Innodb_row_lock_time_max | 0 |
| Innodb_row_lock_waits | 0 |
| Innodb_rows_deleted | 0 |
| Innodb_rows_inserted | 0 |
| Innodb_rows_read | 0 |
| Innodb_rows_updated | 0 |
| Key_blocks_not_flushed | 0 |
| Key_blocks_unused | 214342 |
| Key_blocks_used | 0 |
| Key_read_requests | 0 |
| Key_reads | 0 |
| Key_write_requests | 0 |
| Key_writes | 0 |
| Last_query_cost | 0.000000 |
| Max_used_connections | 1 |
| Not_flushed_delayed_rows | 0 |
| Open_files | 20 |
| Open_streams | 0 |
| Open_table_definitions | 16 |
| Open_tables | 9 |
| Opened_files | 87 |
| Opened_table_definitions | 2 |
| Opened_tables | 2 |
| Prepared_stmt_count | 0 |
| Qcache_free_blocks | 1 |
| Qcache_free_memory | 16758168 |
| Qcache_hits | 0 |
| Qcache_inserts | 1 |
| Qcache_lowmem_prunes | 0 |
| Qcache_not_cached | 9 |
| Qcache_queries_in_cache | 1 |
| Qcache_total_blocks | 4 |
| Queries | 34 |
| Questions | 32 |
| Rpl_status | NULL |
| Select_full_join | 0 |
| Select_full_range_join | 0 |
| Select_range | 0 |
| Select_range_check | 0 |
| Select_scan | 6 |
| Slave_open_temp_tables | 0 |
| Slave_retried_transactions | 0 |
| Slave_running | OFF |
| Slow_launch_threads | 0 |
| Slow_queries | 0 |
| Sort_merge_passes | 0 |
| Sort_range | 0 |
| Sort_rows | 0 |
| Sort_scan | 0 |
| Ssl_accept_renegotiates | 0 |
| Ssl_accepts | 0 |
| Ssl_callback_cache_hits | 0 |
| Ssl_cipher | |
| Ssl_cipher_list | |
| Ssl_client_connects | 0 |
| Ssl_connect_renegotiates | 0 |
| Ssl_ctx_verify_depth | 0 |
| Ssl_ctx_verify_mode | 0 |
| Ssl_default_timeout | 0 |
| Ssl_finished_accepts | 0 |
| Ssl_finished_connects | 0 |
| Ssl_session_cache_hits | 0 |
| Ssl_session_cache_misses | 0 |
| Ssl_session_cache_mode | NONE |
| Ssl_session_cache_overflows | 0 |
| Ssl_session_cache_size | 0 |
| Ssl_session_cache_timeouts | 0 |
| Ssl_sessions_reused | 0 |
| Ssl_used_session_cache_entries | 0 |
| Ssl_verify_depth | 0 |
| Ssl_verify_mode | 0 |
| Ssl_version | |
| Table_locks_immediate | 20 |
| Table_locks_waited | 0 |
| Tc_log_max_pages_used | 0 |
| Tc_log_page_size | 0 |
| Tc_log_page_waits | 0 |
| Threads_cached | 0 |
| Threads_connected | 1 |
| Threads_created | 1 |
| Threads_running | 1 |
| Uptime | 1342 |
| Uptime_since_flush_status | 1342 |
+-----------------------------------+----------+
291 rows in set (0.00 sec)
查询mysql参数
mysql> show variables like 'max_connect%';
+--------------------+-------+
| Variable_name | Value |
+--------------------+-------+
| max_connect_errors | 10 |
| max_connections | 151 |
+--------------------+-------+
2 rows in set (0.00 sec)
修改mysql参数
mysql> set global max_connect_errors = 1000;
Query OK, 0 rows affected (0.00 sec)
查看mysql队列
mysql> show processlist;
+----+------+-----------+------+---------+------+-------+------------------+
| Id | User | Host | db | Command | Time | State | Info |
+----+------+-----------+------+---------+------+-------+------------------+
| 5 | root | localhost | db1 | Query | 0 | NULL | show processlist |
+----+------+-----------+------+---------+------+-------+------------------+
1 row in set (0.00 sec)
创建普通用户并授权
mysql> grant all on *.* to user1 identified by '123456';
Query OK, 0 rows affected (0.00 sec)
mysql> grant all on db1.* to 'user2'@'10.0.2.100' identified by '111222';
Query OK, 0 rows affected (0.00 sec)
mysql> grant all on db1.* to 'user3'@'%' identified by '231222';
Query OK, 0 rows affected (0.00 sec)
mysql>
更改密码
mysql> update mysql.user set password=PASSWORD("root1234") where user='user1';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0
查询user数量
mysql> select count(*) from mysql.user;
+----------+
| count(*) |
+----------+
| 5 |
+----------+
1 row in set (0.00 sec)
查询user权限
mysql> select * from mysql.db\G;
*************************** 1. row ***************************
Host: %
Db: test
User:
Select_priv: Y
Insert_priv: Y
Update_priv: Y
Delete_priv: Y
Create_priv: Y
Drop_priv: Y
Grant_priv: N
References_priv: Y
Index_priv: Y
Alter_priv: Y
Create_tmp_table_priv: Y
Lock_tables_priv: Y
Create_view_priv: Y
Show_view_priv: Y
Create_routine_priv: Y
Alter_routine_priv: N
Execute_priv: N
Event_priv: Y
Trigger_priv: Y
*************************** 2. row ***************************
Host: %
Db: test\_%
User:
Select_priv: Y
Insert_priv: Y
Update_priv: Y
Delete_priv: Y
Create_priv: Y
Drop_priv: Y
Grant_priv: N
References_priv: Y
Index_priv: Y
Alter_priv: Y
Create_tmp_table_priv: Y
Lock_tables_priv: Y
Create_view_priv: Y
Show_view_priv: Y
Create_routine_priv: Y
Alter_routine_priv: N
Execute_priv: N
Event_priv: Y
Trigger_priv: Y
*************************** 3. row ***************************
Host: localhost
Db: discuz
User: gyt
Select_priv: Y
Insert_priv: Y
Update_priv: Y
Delete_priv: Y
Create_priv: Y
Drop_priv: Y
Grant_priv: N
References_priv: Y
Index_priv: Y
Alter_priv: Y
Create_tmp_table_priv: Y
Lock_tables_priv: Y
Create_view_priv: Y
Show_view_priv: Y
Create_routine_priv: Y
Alter_routine_priv: Y
Execute_priv: Y
Event_priv: Y
Trigger_priv: Y
*************************** 4. row ***************************
Host: 10.0.2.100
Db: db1
User: user2
Select_priv: Y
Insert_priv: Y
Update_priv: Y
Delete_priv: Y
Create_priv: Y
Drop_priv: Y
Grant_priv: N
References_priv: Y
Index_priv: Y
Alter_priv: Y
Create_tmp_table_priv: Y
Lock_tables_priv: Y
Create_view_priv: Y
Show_view_priv: Y
Create_routine_priv: Y
Alter_routine_priv: Y
Execute_priv: Y
Event_priv: Y
Trigger_priv: Y
*************************** 5. row ***************************
Host: %
Db: db1
User: user3
Select_priv: Y
Insert_priv: Y
Update_priv: Y
Delete_priv: Y
Create_priv: Y
Drop_priv: Y
Grant_priv: N
References_priv: Y
Index_priv: Y
Alter_priv: Y
Create_tmp_table_priv: Y
Lock_tables_priv: Y
Create_view_priv: Y
Show_view_priv: Y
Create_routine_priv: Y
Alter_routine_priv: Y
Execute_priv: Y
Event_priv: Y
Trigger_priv: Y
5 rows in set (0.00 sec)
ERROR:
No query specified
模糊匹配
mysql> select * from mysql.db where host like '10.0.%'\G;
*************************** 1. row ***************************
Host: 10.0.2.100
Db: db1
User: user2
Select_priv: Y
Insert_priv: Y
Update_priv: Y
Delete_priv: Y
Create_priv: Y
Drop_priv: Y
Grant_priv: N
References_priv: Y
Index_priv: Y
Alter_priv: Y
Create_tmp_table_priv: Y
Lock_tables_priv: Y
Create_view_priv: Y
Show_view_priv: Y
Create_routine_priv: Y
Alter_routine_priv: Y
Execute_priv: Y
Event_priv: Y
Trigger_priv: Y
1 row in set (0.00 sec)
ERROR:
No query specified
mysql>
更新表数据
mysql> update db1.t1 set name='aaa' where id=1;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> use db1;select * from db1;
Database changed
ERROR 1146 (42S02): Table 'db1.db1' doesn't exist
mysql> use db1;select * from t1;
Database changed
+------+------+
| id | name |
+------+------+
| 1 | aaa |
+------+------+
1 row in set (0.00 sec)
mysql>
修复表
mysql> repair table t1[use frm];
shell命令中执行mysql操作
[root@localhost ~]# /usr/local/mysql/bin/mysql -uroot -pmysql1234 mysql -e "show tables"
+---------------------------+
| Tables_in_mysql |
+---------------------------+
| columns_priv |
| db |
| event |
| func |
| general_log |
| help_category |
| help_keyword |
| help_relation |
| help_topic |
| host |
| ndb_binlog_index |
| plugin |
| proc |
| procs_priv |
| servers |
| slow_log |
| tables_priv |
| time_zone |
| time_zone_leap_second |
| time_zone_name |
| time_zone_transition |
| time_zone_transition_type |
| user |
+---------------------------+
[root@localhost ~]#
mysql备份与恢复
备份
[root@localhost ~]# /usr/local/mysql/bin/mysqldump -uroot -p --events mysql >1.sql
Enter password:
[root@localhost ~]# du -sh 1.sql
516K 1.sql
恢复
[root@localhost ~]# /usr/local/mysql/bin/mysqldump -uroot -p --events mysql <1.sql
只备份一个表
[root@localhost ~]# /usr/local/mysql/bin/mysqldump -uroot -p discuz pre_ucenter_vars >2.sql
Enter password:
[root@localhost ~]# du -sh 2.sql
4.0K 2.sql
[root@localhost ~]#
恢复时不需要加表名字
[root@localhost ~]# /usr/local/mysql/bin/mysqldump -uroot -p discuz <2.sql
备份时指定字符集
[root@localhost ~]# /usr/local/mysql/bin/mysqldump -uroot -p --default-character-set=utf8 discuz >1.sql
Enter password:
[root@localhost ~]# du -sh 1.sql
2.3M 1.sql
[root@localhost ~]#
恢复时也指定字符集
[root@localhost ~]# /usr/local/mysql/bin/mysqldump -uroot -p --default-character-set=utf8 discuz <1.sql
mysql主从
介绍
Mysql Replication主要用于时时备份，或者读写分离。
每个从仅可以设置一个主
主在执行sql之后，记录二进制log文件(bin-log)。
从连接主，并从主获取binlog，存于本地relay-log,并从上次记住位置执行sql，一旦遇到错误则停止同步。
主从间的数据库不是实时同步，就算网络连接正常，也存在瞬间，主从数据不一致。
如果主从网络断开，从会在网络正常后，批量同步。
如果对从进行修改数据，那么很可能从在执行主的bin-log时出现错误而停止同步，危险操作。
可以是1主多从，也可以是相互主从（主主）。可以应用在读写分离场景中，用以降低单台mysql服务器的I/O，可以实现mysql服务HA集群。
如果重启master，一定先把slave停掉，执行slave stop命令。然后再重启master的mysql。
步骤
安装步骤参照lamp中mysql步骤。
#在主上创建测试库
/usr/local/mysql/bin/mysql -uroot -S /tmp/mysql.sock -e "create database db1;"
导出主mysql库数据给db1
/usr/local/mysql/bin/mysqldump -uroot -S /tmp/mysql.sock mysql >123.sql
/usr/local/mysql/bin/mysql -uroot -S /tmp/mysql.sock db1 <123.sql
#配置主库
vim /etc/my.cnf
# required unique id between 1 and 2^32 - 1
# defaults to 1 if master-host is not set
# but will not function as a master if omitted
server-id = 1
# Replication Master Server (default)
# binary logging is required for replication
log-bin=mysql-bin
#用来指定需要同步的库，2选1，或指定忽略不同步的库
binlog-do-db=db1
binlog-ignore-db=db1,db2
#修改配置文件后，重启主服务
service mysqld stop
service mysqld start
#主mysql设置root密码
/usr/local/mysql/bin/mysqladmin -u root -S /tmp/mysql.sock password 'root1234'
#进入mysql主 shell
/usr/local/mysql/bin/mysql -u root -S /tmp/mysql.sock -p"root1234"
#授权给从一个用来同步数据的用户rep1
mysql> grant replication slave on *.* to 'repl'@192.168.211.128' identified by 'root1234';
mysql> flush tables with read lock;
#记住前2列内容
mysql>show master status;
#从上设置
vim /etc/my.cnf
# required unique id between 1 and 2^32 - 1
# defaults to 1 if master-host is not set
# but will not function as a master if omitted
server-id = 2
#重启从Mysql服务
service mysqld restart
#从主上拷贝db1库数据到从
scp db1.sql root@192.168.211.128:/root/
#在从上创建db1数据库
/usr/local/mysql/bin/mysql -uroot -S /tmp/mysql.sock -e "create database db1";
#在从上导入db1从库
/usr/local/mysql/bin/mysql -uroot -S /tmp/mysql.sock db1 </root/db1.sql
#登录从mysql
/usr/local/mysql/bin/mysql -uroot -S /tmp/mysql.sock
#停止从库
mysql>slave stop
#在从上设置主库参数，此处master_log_file和master_log_pos为主上show master status看到的前2列值
mysql> change master to master_host='192.168.211.133',master_port=3306,master_user='repl',master_password='root1234',master_log_file='mysql-bin.000004',master_log_pos=555;
Query OK, 0 rows affected (0.03 sec)
#在从上启动数据库
mysql> slave start;
Query OK, 0 rows affected (0.00 sec)
#主上执行unlock read
/usr/local/mysql/bin/mysql -uroot -S /tmp/mysql.sock -proot1234 -e "unlock tables"
#从上查看状态，有这2个Yes，算正常
mysql> show slave status\G;
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
测试
#主上清空db1K库db表
mysql> use db1;
Database changed
mysql> select count(*) from db;
+----------+
| count(*) |
+----------+
| 2 |
+----------+
1 row in set (0.00 sec)
mysql> truncate table db;
Query OK, 0 rows affected (0.00 sec)
#进入从，确认为0，说明同步
mysql> use db1;
Database changed
mysql> select count(*) from db;
+----------+
| count(*) |
+----------+
| 0 |
+----------+
1 row in set (0.00 sec)
#主上删除表db
mysql> select count(*) from db;
ERROR 1146 (42S02): Table 'db1.db' doesn't exist
#在从上db表不存在了
mysql> drop table db;
Query OK, 0 rows affected (0.00 sec)
