MySQL备份恢复 mysqldump命令{alert type="info"}逻辑备份工具。文本形式保存备份，可读性较强。备份逻辑： 将建库、建表、数据插入语句导出，包存至一个sql文件中。比较适合于：数据量较小的场景，单表数据行千万级别以内。百G以内的小型数据库.跨版本、跨平台迁移。可以本地、可以远程备份。注意： 一般情况下，恢复需要耗费的时间是备份耗费时间的3-5倍。{/alert}连接参数：mysqldump -u -p -S -h -P{message type="info" content="-u 用户-p 密码-S 指定连接mysql的socket文件位置，默认路径/tmp/mysql.sock-h IP地址-P 端口（默认3306）"/}备份参数：-A：全备份[root@cs ~]# mysqldump -uroot -p123 -A >/data/backup/full.sql-B：单库或者多库备份[root@cs ~]# mysqldump -uroot -p123 -B test cs >/data/backup/db.sql单表或者多表备份[root@cs ~]# mysqldump -uroot -p123 -B world city country >/data/backup/biao.sql{alert type="warning"}注意：-A 和 -B 都带有了 create database 和use 语句，直接恢复即可单表或多表备份方式, 没有 create database 和use 语句，所以要手工进行建库和use，再恢复数据。{/alert}高级功能参数参数一： --master-data=2自动记录binlog位置点 b. 自动加GRL锁(FTWRL ,flush tables with read lock) c. 配合--single-transaction ,减少锁的时间。参数二： single-transaction对于InnoDB表，利用MVCC中一致性快照进行备份。备份数据时,不加锁 b. 备份期间如果出现DDL操作，导致备份数据不一致 问题： mysqldump是严格意义上的热备吗？ 8.0 之后 master-data和single-transaction,对于InnoDB数据备份时是快照备份的. 备份表结构等数据时,还是FTWRL过程备份. --single-transaction 只是针对InnoDB表数据进行一致性快照备份。 问题： mysqldump备份需要锁表吗？ 是有的。global read lock参数三： -R -E --triggers 备份特殊对象存储过程 函数 触发器 事件参数四： --max_allowed_packet=64M最大允许数据包的大小。标准化备份[root@cs backup]# mysqldump -uroot -p -A --master-data=2 --single-transaction -R -E --triggers --max_allowed_packet=64M >/data/backup/full_`date +%F`.sql Enter password: 实验：通过mysqldump全备+binlog实现PIT数据恢复{alert type="info"}环境背景： 小型的业务数据库，50G，每天23:00全备，定期binlog异地备份。故障场景： 周三下午2点，开发Navicat连接数据库实例错误，导致生产数据被误删除（DROP）恢复思路：挂维护页。检查备份、日志可用。如果只是部分损坏，建议找一个应急库进行恢复全备恢复日志截取并恢复恢复后数据校验 （业务测试部门验证）立即备份（停机冷备）恢复架构系统撤维护页，恢复业务{/alert}环境搭建mysql> create database mdb; Query OK, 1 row affected (0.00 sec) mysql> use mdb; Database changed mysql> create table t1 (id int); Query OK, 0 rows affected (0.03 sec) mysql> create table t2 (id int); Query OK, 0 rows affected (0.03 sec) mysql> create table t3 (id int); Query OK, 0 rows affected (0.03 sec) mysql> insert into t1 values(1),(2),(3); Query OK, 3 rows affected (0.01 sec) Records: 3 Duplicates: 0 Warnings: 0 mysql> insert into t2 values(1),(2),(3); Query OK, 3 rows affected (0.01 sec) Records: 3 Duplicates: 0 Warnings: 0 mysql> insert into t3 values(1),(2),(3); Query OK, 3 rows affected (0.01 sec) Records: 3 Duplicates: 0 Warnings: 0 mysql> commit; Query OK, 0 rows affected (0.00 sec) [root@cs ~]# mysqldump -uroot -p -A --master-data=2 --single-transaction -R -E --triggers --max_allowed_packet=64M >/tmp/full_`date +%F`.sql Enter password: mysql> create table t4 (id int); Query OK, 0 rows affected (0.09 sec) mysql> insert into t4 values (1),(2),(3); Query OK, 3 rows affected (0.01 sec) Records: 3 Duplicates: 0 Warnings: 0 mysql> commit; Query OK, 0 rows affected (0.00 sec) mysql> drop database mdb; Query OK, 4 rows affected (0.06 sec)恢复过程查看备份获取二进制位置点mysql> show binary logs; +------------------+-----------+ | Log_name | File_size | +------------------+-----------+ | mysql-bin.000001 | 177 | | mysql-bin.000002 | 201 | | mysql-bin.000003 | 201 | | mysql-bin.000004 | 3513 | +------------------+-----------+ 4 rows in set (0.00 sec) mysql> show binlog events in 'mysql-bin.000004'; +------------------+------+----------------+-----------+-------------+---------------------------------- | Log_name | Pos | Event_type | Server_id | End_log_pos | Info +------------------+------+----------------+-----------+-------------+---------------------------------- |........................................................................................................ | mysql-bin.000004 | 1580 | Query | 1 | 1671 | create database mdb | | mysql-bin.000004 | 1671 | Anonymous_Gtid | 1 | 1736 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000004 | 1736 | Query | 1 | 1832 | use `mdb`; create table t1 (id int) | | mysql-bin.000004 | 1832 | Anonymous_Gtid | 1 | 1897 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000004 | 1897 | Query | 1 | 1993 | use `mdb`; create table t2 (id int) | | mysql-bin.000004 | 1993 | Anonymous_Gtid | 1 | 2058 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000004 | 2058 | Query | 1 | 2154 | use `mdb`; create table t3 (id int) | | mysql-bin.000004 | 2154 | Anonymous_Gtid | 1 | 2219 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000004 | 2219 | Query | 1 | 2290 | BEGIN | | mysql-bin.000004 | 2290 | Table_map | 1 | 2334 | table_id: 131 (mdb.t1) | | mysql-bin.000004 | 2334 | Write_rows | 1 | 2384 | table_id: 131 flags: STMT_END_F | | mysql-bin.000004 | 2384 | Xid | 1 | 2415 | COMMIT /* xid=1405 */ | | mysql-bin.000004 | 2415 | Anonymous_Gtid | 1 | 2480 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000004 | 2480 | Query | 1 | 2551 | BEGIN | | mysql-bin.000004 | 2551 | Table_map | 1 | 2595 | table_id: 132 (mdb.t2) | | mysql-bin.000004 | 2595 | Write_rows | 1 | 2645 | table_id: 132 flags: STMT_END_F | | mysql-bin.000004 | 2645 | Xid | 1 | 2676 | COMMIT /* xid=1406 */ | | mysql-bin.000004 | 2676 | Anonymous_Gtid | 1 | 2741 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000004 | 2741 | Query | 1 | 2812 | BEGIN | | mysql-bin.000004 | 2812 | Table_map | 1 | 2856 | table_id: 133 (mdb.t3) | | mysql-bin.000004 | 2856 | Write_rows | 1 | 2906 | table_id: 133 flags: STMT_END_F | | mysql-bin.000004 | 2906 | Xid | 1 | 2937 | COMMIT /* xid=1407 */ | | mysql-bin.000004 | 2937 | Anonymous_Gtid | 1 | 3002 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000004 | 3002 | Query | 1 | 3098 | use `mdb`; create table t4 (id int) | | mysql-bin.000004 | 3098 | Anonymous_Gtid | 1 | 3163 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000004 | 3163 | Query | 1 | 3234 | BEGIN | | mysql-bin.000004 | 3234 | Table_map | 1 | 3278 | table_id: 366 (mdb.t4) | | mysql-bin.000004 | 3278 | Write_rows | 1 | 3328 | table_id: 366 flags: STMT_END_F | | mysql-bin.000004 | 3328 | Xid | 1 | 3359 | COMMIT /* xid=4749 */ | | mysql-bin.000004 | 3359 | Anonymous_Gtid | 1 | 3424 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000004 | 3424 | Query | 1 | 3513 | drop database mdb | +------------------+------+----------------+-----------+-------------+---------------------------------------+ 恢复备份 mysql> source /tmp/full_2021-08-25.sql; 二进制恢复 [root@cs tmp]# mysqlbinlog --skip-gtids --start-position=1580 --stop-position=3424 /var/lib/mysql/mysql-bin.000004 >/tmp/bin1.sql mysql> set sql_log_bin=0; mysql> source /tmp/bin.sql mysql> set sql_log_bin=1;{alert type="warning"}100G mysqldump全备恢复时间很长，误删除的表10M大小 ，有什么思路可以快速恢复？思路： a. 从全备中，将单表 建表语句和insert语句提取出来 ，进行恢复 sed -e'/./{H;$!d;}' -e 'x;/CREATE TABLE `oldguo`/!d;q' /data/backup/mdp/full.sql>/data/createtable.sql grep -i 'INSERT INTO `oldguo`' /data/backup/mdp/full.sql >/data/data.sql b. 从binlog中单独截取单表的所有binlog，进行恢复。 binlog2sql 截取单表binlog，恢复。{/alert}物理备份工具使用-Percona Xtrabackup（PXB）{alert type="info"}物理备份工具，支持全备和增量备份。备份逻辑：数据库运行期间，拷贝数据表空间.拷贝的同时，会将备份期间的redo进行备份恢复逻辑 ：模拟了InnoDB Crash Recovery 功能，需要要将备份进行处理（前滚和回滚）后才能恢复{/alert}安装yum 源[root@cs ~]# yum install https://repo.percona.com/yum/percona-release-latest.noarch.rpm -y安装XtraBackup 2.4版本的[root@cs ~]# yum install -y percona-xtrabackup-24.x86_641.全量备份[root@cs backup]# innobackupex --user=root --password=123 /tmp/backup &>/tmp/xbk.log自主定制备份路径名[root@cs backup]# innobackupex --user=root --password=123 --no-timestamp /data/backup/full &>/tmp/xbk.log全备的恢复准备备份（Prepared）将redo进行重做，已提交的写到数据文件，未提交的使用undo回滚掉。模拟了CSR的过程[root@cs lib]# innobackupex --apply-log /tmp/backup/full/恢复备份前提：1、被恢复的目录是空 2、被恢复的数据库的实例是关闭 systemctl stop mysqld创建新目录[root@cs backup]# mkdir /var/lib/mysql数据拷贝[root@cs lib]# innobackupex --copy-back /tmp/backup/full/启动数据库systemctl start mysqldinnobackupex 增量备份(incremental)（1）增量备份的方式，是基于上一次备份进行增量。 （2）增量备份无法单独恢复。必须基于全备进行恢复。 （3）所有增量必须要按顺序合并到全备中。前期准备mysql> create database test charset utf8; Query OK, 1 row affected (0.01 sec) mysql> use test; Database changed mysql> create table t1 (id int); Query OK, 0 rows affected (0.03 sec) mysql> insert into t1 values(1),(2),(3); Query OK, 3 rows affected (0.01 sec) Records: 3 Duplicates: 0 Warnings: 0 mysql> select * from t1; +------+ | id | +------+ | 1 | | 2 | | 3 | +------+ 3 rows in set (0.00 sec) mysql> commit; Query OK, 0 rows affected (0.00 sec)增量备份命令# 全备 （周日） [root@cs tmp]# innobackupex --user=root --password=123 --no-timestamp /tmp/backup/full &> /tmp/xbk.log # 模拟数据变化 （周一） mysql> create database cs; Query OK, 1 row affected (0.00 sec) mysql> use cs; Database changed mysql> create table t1 (id int); Query OK, 0 rows affected (0.03 sec) mysql> insert into t1 values (1),(2),(3); Query OK, 3 rows affected (0.01 sec) Records: 3 Duplicates: 0 Warnings: 0 mysql> commit; Query OK, 0 rows affected (0.00 sec) #周一备份 [root@cs tmp]# innobackupex --user=root --password=123 --no-timestamp --incremental /tmp/backup/inc1 --incremental-basedir=/tmp/backup/full &>/tmp/inc1.log #模拟周二数据（cs） mysql> create table t2 (id int); Query OK, 0 rows affected (0.03 sec) mysql> insert into t2 values(1),(2),(3); Query OK, 3 rows affected (0.00 sec) Records: 3 Duplicates: 0 Warnings: 0 mysql> commit; Query OK, 0 rows affected (0.00 sec) #周二备份 [root@cs backup]# innobackupex --user=root --password=123 --no-timestamp --incremental /tmp/backup/inc2 --incremental-basedir=/tmp/backup/inc1 &>/tmp/inc2.log # 模拟周三数据变化 mysql> create table t3 (id int); Query OK, 0 rows affected (0.02 sec) mysql> insert into t3 values(1),(2),(3); Query OK, 3 rows affected (0.01 sec) Records: 3 Duplicates: 0 Warnings: 0 mysql> commit; Query OK, 0 rows affected (0.00 sec) mysql> drop database cs; Query OK, 3 rows affected (0.04 sec)恢复到周三误drop之前的数据状态恢复思路： 1. 挂出维护页，停止当天的自动备份脚本 2. 检查备份：周日full+周一inc1+周二inc2，周三的完整二进制日志 3. 进行备份整理（细节），截取关键的二进制日志（从备份——误删除之前） 4. 测试库进行备份恢复及日志恢复 5. 应用进行测试无误，开启业务 6. 此次工作的总结开始恢复(1) 全备的整理 [root@cs backup]# innobackupex --apply-log --redo-only /tmp/backup/full/ (2) 合并inc1到full中 [root@cs backup]# innobackupex --apply-log --redo-only --incremental-dir=/tmp/backup/inc1 /tmp/backup/full/ (3) 合并inc2到full中 [root@cs backup]# innobackupex --apply-log --incremental-dir=/tmp/backup/inc2 /tmp/backup/full/ (4) 最后一次整理全备 [root@cs backup]# innobackupex --apply-log /tmp/backup/full (5) 二进制截取 判断起点 [root@cs backup]# cat inc2/xtrabackup_binlog_info mysql-bin.000001 2463 判断终点 mysql> show binlog events in 'mysql-bin.000001'; +------------------+------+----------------+-----------+-------------+---------------------------------------+ | Log_name | Pos | Event_type | Server_id | End_log_pos | Info | +------------------+------+----------------+-----------+-------------+---------------------------------------+ | mysql-bin.000001 | 4 | Format_desc | 1 | 123 | Server ver: 5.7.34-log, Binlog ver: 4 | | mysql-bin.000001 | 123 | Previous_gtids | 1 | 154 | | | mysql-bin.000001 | 154 | Anonymous_Gtid | 1 | 219 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000001 | 219 | Query | 1 | 326 | create database test charset utf8 | | mysql-bin.000001 | 326 | Anonymous_Gtid | 1 | 391 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000001 | 391 | Query | 1 | 489 | use `test`; create table t1 (id int) | | mysql-bin.000001 | 489 | Anonymous_Gtid | 1 | 554 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000001 | 554 | Query | 1 | 626 | BEGIN | | mysql-bin.000001 | 626 | Table_map | 1 | 671 | table_id: 122 (test.t1) | | mysql-bin.000001 | 671 | Write_rows | 1 | 721 | table_id: 122 flags: STMT_END_F | | mysql-bin.000001 | 721 | Xid | 1 | 752 | COMMIT /* xid=68 */ | | mysql-bin.000001 | 752 | Anonymous_Gtid | 1 | 817 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000001 | 817 | Query | 1 | 905 | create database cs | | mysql-bin.000001 | 905 | Anonymous_Gtid | 1 | 970 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000001 | 970 | Query | 1 | 1064 | use `cs`; create table t1 (id int) | | mysql-bin.000001 | 1064 | Anonymous_Gtid | 1 | 1129 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000001 | 1129 | Query | 1 | 1199 | BEGIN | | mysql-bin.000001 | 1199 | Table_map | 1 | 1242 | table_id: 123 (cs.t1) | | mysql-bin.000001 | 1242 | Write_rows | 1 | 1292 | table_id: 123 flags: STMT_END_F | | mysql-bin.000001 | 1292 | Xid | 1 | 1323 | COMMIT /* xid=81 */ | | mysql-bin.000001 | 1323 | Anonymous_Gtid | 1 | 1388 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000001 | 1388 | Query | 1 | 1474 | drop database cs | | mysql-bin.000001 | 1474 | Anonymous_Gtid | 1 | 1539 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000001 | 1539 | Query | 1 | 1627 | create database cs | | mysql-bin.000001 | 1627 | Anonymous_Gtid | 1 | 1692 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000001 | 1692 | Query | 1 | 1786 | use `cs`; create table t1 (id int) | | mysql-bin.000001 | 1786 | Anonymous_Gtid | 1 | 1851 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000001 | 1851 | Query | 1 | 1921 | BEGIN | | mysql-bin.000001 | 1921 | Table_map | 1 | 1964 | table_id: 423 (cs.t1) | | mysql-bin.000001 | 1964 | Write_rows | 1 | 2014 | table_id: 423 flags: STMT_END_F | | mysql-bin.000001 | 2014 | Xid | 1 | 2045 | COMMIT /* xid=113 */ | | mysql-bin.000001 | 2045 | Anonymous_Gtid | 1 | 2110 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000001 | 2110 | Query | 1 | 2204 | use `cs`; create table t2 (id int) | | mysql-bin.000001 | 2204 | Anonymous_Gtid | 1 | 2269 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000001 | 2269 | Query | 1 | 2339 | BEGIN | | mysql-bin.000001 | 2339 | Table_map | 1 | 2382 | table_id: 728 (cs.t2) | | mysql-bin.000001 | 2382 | Write_rows | 1 | 2432 | table_id: 728 flags: STMT_END_F | | mysql-bin.000001 | 2432 | Xid | 1 | 2463 | COMMIT /* xid=136 */ | | mysql-bin.000001 | 2463 | Anonymous_Gtid | 1 | 2528 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000001 | 2528 | Query | 1 | 2622 | use `cs`; create table t3 (id int) | | mysql-bin.000001 | 2622 | Anonymous_Gtid | 1 | 2687 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000001 | 2687 | Query | 1 | 2757 | BEGIN | | mysql-bin.000001 | 2757 | Table_map | 1 | 2800 | table_id: 1034 (cs.t3) | | mysql-bin.000001 | 2800 | Write_rows | 1 | 2850 | table_id: 1034 flags: STMT_END_F | | mysql-bin.000001 | 2850 | Xid | 1 | 2881 | COMMIT /* xid=159 */ | | mysql-bin.000001 | 2881 | Anonymous_Gtid | 1 | 2946 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000001 | 2946 | Query | 1 | 3032 | drop database cs | +-----------------+------+----------------+-----------+-------------+---------------------------------------+ 恢复3. 截取周二 23:00 到drop 之前的 binlog [root@cs backup]# mysqlbinlog --start-position=2463 --stop-position=2946 /var/lib/mysql/mysql-bin.000001 >/tmp/backup/bin.sql 4. 进行恢复 [root@cs lib]# innobackupex --copy-back /tmp/backup/full/ [root@cs lib]# chown -R mysql.mysql mysql [root@cs lib]# systemctl start mysqld 二进制恢复 mysql> set sql_log_bin=0; Query OK, 0 rows affected (0.00 sec) mysql> source /tmp/backup/bin.sql; Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Database changed Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Charset changed Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected, 1 warning (0.00 sec) Query OK, 0 rows affected (0.03 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) mysql> show tables; +--------------+ | Tables_in_cs | +--------------+ | t1 | | t2 | | t3 | +--------------+ 3 rows in set (0.00 sec) mysql> set sql_log_bin=1;

MySQL二进制日志截取和恢复 作用数据恢复和主从配置开启二进制日志vim /etc/my.conf [mysqld] server-id=1 #（1~65535） log-bin=/var/lib/mysql/mysql-bin log_bin_index=/var/lib/mysql/mysql-bin.index binlog_format=row sync_binlog=1 //每次事务提交都立即刷写binlog到磁盘 mysql> show variables like '%log_bin%'; +---------------------------------+--------------------------------+ | Variable_name | Value | +---------------------------------+--------------------------------+ | log_bin | ON | | log_bin_basename | /var/lib/mysql/mysql-bin | | log_bin_index | /var/lib/mysql/mysql-bin.index | | log_bin_trust_function_creators | OFF | | log_bin_use_v1_row_events | OFF | | sql_log_bin | ON | +---------------------------------+--------------------------------+ 6 rows in set (0.00 sec)PS:binlog_format=(row、statement、mixed)statement：SBR,语句模式记录日志,做什么命令,记录什么命令. 可读性较强,对于范围操作日志量少,但是可能会出现记录不准确的情况：insert into xx values (1,'sa',now()). row ：RBR,行模式,数据行的变化。可读性较弱,对于范围操作日志大,不会出现记录错误.对高可用环境中的新特性要依赖于RBR(5.7版本默认) mixed ：MBR,混合模式查看二进制日志位置：mysql> show variables like '%log_bin%'; # flush logs; 每执行一次就多一个日志 +---------------------------------+--------------------------------+ | Variable_name | Value | +---------------------------------+--------------------------------+ | log_bin | ON | | log_bin_basename | /var/lib/mysql/mysql-bin | | log_bin_index | /var/lib/mysql/mysql-bin.index | | log_bin_trust_function_creators | OFF | | log_bin_use_v1_row_events | OFF | | sql_log_bin | ON | +---------------------------------+--------------------------------+ 6 rows in set (0.01 sec) mysql> show binary logs; +------------------+-----------+ | Log_name | File_size | +------------------+-----------+ | mysql-bin.000001 | 177 | | mysql-bin.000002 | 154 | +------------------+-----------+ 2 rows in set (0.00 sec) mysql> flush logs; Query OK, 0 rows affected (0.01 sec) mysql> show binary logs; +------------------+-----------+ | Log_name | File_size | +------------------+-----------+ | mysql-bin.000001 | 177 | | mysql-bin.000002 | 201 | | mysql-bin.000003 | 154 | +------------------+-----------+ 3 rows in set (0.00 sec)查看现存的二进制日志show binary logs;查看二进制日志事件show binlog events in 'mysql-bin.000003' limit 5; +------------------+-----+----------------+-----------+-------------+---------------------------------------+ | Log_name | Pos | Event_type | Server_id | End_log_pos | Info | +------------------+-----+----------------+-----------+-------------+---------------------------------------+ | mysql-bin.000003 | 4 | Format_desc | 1 | 123 | Server ver: 5.7.34-log, Binlog ver: 4 | | mysql-bin.000003 | 123 | Previous_gtids | 1 | 154 | | +------------------+-----+----------------+-----------+-------------+---------------------------------------+ 2 rows in set (0.00 sec)在打印出来的信息中可以看到event事件的开始和结束号码，它可以方便我们从日志中截取想要的日志事件查看二进制日志内容[root@cs mysql]# mysqlbinlog mysql-bin.000003 /*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=1*/; /*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/; DELIMITER /*!*/; # at 4 #210822 10:27:13 server id 1 end_log_pos 123 CRC32 0x98688dd8 Start: binlog v 4, server v 5.7.34-log created 210822 10:27:13 # Warning: this binlog is either in use or was not closed properly. BINLOG ' AbYhYQ8BAAAAdwAAAHsAAAABAAQANS43LjM0LWxvZwAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAEzgNAAgAEgAEBAQEEgAAXwAEGggAAAAICAgCAAAACgoKKioAEjQA AdiNaJg= '/*!*/; # at 123 #210822 10:27:13 server id 1 end_log_pos 154 CRC32 0x1ae7a1b6 Previous-GTIDs # [empty] SET @@SESSION.GTID_NEXT= 'AUTOMATIC' /* added by mysqlbinlog */ /*!*/; DELIMITER ; # End of log file /*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/; /*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;查看和分析binlogmysql> show binary logs; mysql> show master status ; mysql> show binlog events in 'binlog.000003'; [root@cs mysql]# mysqlbinlog mysql-bin.000003 [root@cs mysql]# mysqlbinlog --base64-output=decode-rows -vvv mysql-bin.000003模拟数据恢复mysql> flush logs; mysql> create database cs; mysql> use cs; Database changed mysql> create table t1 (id int); Query OK, 0 rows affected (0.05 sec) mysql> insert into t1 values(1); Query OK, 1 row affected (0.01 sec) mysql> commit; Query OK, 0 rows affected (0.00 sec) mysql> insert into t1 values(2); Query OK, 1 row affected (0.01 sec) mysql> commit; Query OK, 0 rows affected (0.00 sec) mysql> insert into t1 values(3); Query OK, 1 row affected (0.01 sec) mysql> commit; Query OK, 0 rows affected (0.00 sec) mysql> drop cs; 开始恢复 mysql> show master status; #当前的二进制文件 +------------------+----------+--------------+------------------+-------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +------------------+----------+--------------+------------------+-------------------+ | mysql-bin.000004 | 1364 | | | | +------------------+----------+--------------+------------------+-------------------+ 1 row in set (0.00 sec) mysql> show binlog events in 'mysql-bin.000004'; #查看二进制日志事件（重要的是创建数据库和删除数据库的Pos值） +------------------+------+----------------+-----------+-------------+---------------------------------------+ | Log_name | Pos | Event_type | Server_id | End_log_pos | Info | +------------------+------+----------------+-----------+-------------+---------------------------------------+ | mysql-bin.000004 | 4 | Format_desc | 1 | 123 | Server ver: 5.7.34-log, Binlog ver: 4 | | mysql-bin.000004 | 123 | Previous_gtids | 1 | 154 | | | mysql-bin.000004 | 154 | Anonymous_Gtid | 1 | 219 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000004 | 219 | Query | 1 | 307 | create database cs | | mysql-bin.000004 | 307 | Anonymous_Gtid | 1 | 372 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000004 | 372 | Query | 1 | 466 | use `cs`; create table t1 (id int) | | mysql-bin.000004 | 466 | Anonymous_Gtid | 1 | 531 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000004 | 531 | Query | 1 | 601 | BEGIN | | mysql-bin.000004 | 601 | Table_map | 1 | 644 | table_id: 115 (cs.t1) | | mysql-bin.000004 | 644 | Write_rows | 1 | 684 | table_id: 115 flags: STMT_END_F | | mysql-bin.000004 | 684 | Xid | 1 | 715 | COMMIT /* xid=349 */ | | mysql-bin.000004 | 715 | Anonymous_Gtid | 1 | 780 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000004 | 780 | Query | 1 | 850 | BEGIN | | mysql-bin.000004 | 850 | Table_map | 1 | 893 | table_id: 115 (cs.t1) | | mysql-bin.000004 | 893 | Write_rows | 1 | 933 | table_id: 115 flags: STMT_END_F | | mysql-bin.000004 | 933 | Xid | 1 | 964 | COMMIT /* xid=351 */ | | mysql-bin.000004 | 964 | Anonymous_Gtid | 1 | 1029 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000004 | 1029 | Query | 1 | 1099 | BEGIN | | mysql-bin.000004 | 1099 | Table_map | 1 | 1142 | table_id: 115 (cs.t1) | | mysql-bin.000004 | 1142 | Write_rows | 1 | 1182 | table_id: 115 flags: STMT_END_F | | mysql-bin.000004 | 1182 | Xid | 1 | 1213 | COMMIT /* xid=353 */ | | mysql-bin.000004 | 1213 | Anonymous_Gtid | 1 | 1278 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' | | mysql-bin.000004 | 1278 | Query | 1 | 1364 | drop database cs | +------------------+------+----------------+-----------+-------------+---------------------------------------+ 23 rows in set (0.00 sec) [root@cs mysql]# mysqlbinlog --start-position=219 --stop-position=1278 /var/lib/mysql/mysql-bin.000004 >/tmp/bin.sql mysql> set sql_log_bin=0; #下面操作不会被记录到二进制文件（慎用） Query OK, 0 rows affected (0.00 sec) mysql> source /tmp/bin.sql; Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.01 sec) Query OK, 0 rows affected (0.00 sec) Charset changed Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected, 1 warning (0.00 sec) Query OK, 1 row affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Database changed Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.02 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.01 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) mysql> set sql_log_bin=1; Query OK, 0 rows affected (0.00 sec) mysql> use cs; Database changed mysql> show tables; +--------------+ | Tables_in_cs | +--------------+ | t1 | +--------------+ 1 row in set (0.00 sec) mysql> select * from t1; +------+ | id | +------+ | 1 | | 2 | | 3 | +------+ 3 rows in set (0.00 sec)

MySQL开启慢查询日志 前言数据库日志记录了用户对数据库的各种操作及数据库发生的各种事件。能帮助数据库管理员追踪、分析问题。MySQL提供了错误日志、二进制日志、查询日志、慢查询日志。MySQL的慢查询日志是MySQL提供的一种日志记录，它用来记录在MySQL中响应时间超过阀值(long_query_time，单位：秒)的SQL语句。默认情况下，MySQL不启动慢查询日志。本文简单介绍如何开启慢查询日志，如何用mysqldumpslow分析慢查询。参数说明：slow_query_log #慢查询开启状态，ON开启，OFF关闭 slow_query_log_file #慢查询日志存放的位置（这个目录需要MySQL的运行帐号的可写权限，一般设置为MySQL的数据存放目录） long_query_time #查询超过多少秒才记录 默认10s ，查询命令 SHOW VARIABLES LIKE 'long_query_time'; log_queries_not_using_indexes = 1 #表明记录没有使用索引的 SQL 语句重点说明：开启慢日志版本要高，低版本无法支持，本次版本是： 5.7.34SELECT VERSION(); #查询版本号 或者 show variables like '%version%'配置开启慢查询编辑MySQL配置文件my.cnf在【mysqld】字段下加入：long_query_time=1 #表示记录查询超过1s的sql slow_launch_time=1 #表示如果建立线程花费了比这个值更长的时间,slow_launch_threads 计数器将增加 slow_query_log=ON #开启慢查询日志 slow_query_log_file=/var/lib/mysql/slow_queries.log #慢查询日志记录文件{message type="warning" content="注意：慢查询的日志记录文件对于mysql用户必须可写！！"/}mysql> show variables like 'slow_query%'; +---------------------+---------------------------------+ | Variable_name | Value | +---------------------+---------------------------------+ | slow_query_log | ON | | slow_query_log_file | /var/lib/mysql/slow_queries.log | +---------------------+---------------------------------+ 2 rows in set (0.00 sec) mysql> SHOW VARIABLES LIKE 'long_query_time'; +-----------------+----------+ | Variable_name | Value | +-----------------+----------+ | long_query_time | 1.000000 | +-----------------+----------+ 1 row in set (0.00 sec)测试mysql> select sleep(2); +----------+ | sleep(2) | +----------+ | 0 | +----------+ 1 row in set (2.02 sec)[root@cs ~]# cat /var/lib/mysql/slow_queries.log /usr/sbin/mysqld, Version: 5.7.34-log (MySQL Community Server (GPL)). started with: Tcp port: 0 Unix socket: /var/lib/mysql/mysql.sock Time Id Command Argument # Time: 2021-08-20T10:01:18.841053Z # User@Host: root[root] @ localhost [] Id: 3 # Query_time: 2.023306 Lock_time: 0.000000 Rows_sent: 1 Rows_examined: 0 SET timestamp=1629453678; select sleep(2);删除慢查询日志慢查询日志的删除方法与通用日志的删除方法是一样的。可以使用 mysqladmin 命令来删除。也可以使用手工方式来删除。mysqladmin 命令的语法如下：mysqladmin -uroot -p flush-logs执行该命令后，命令行会提示输入密码。输入正确密码后，将执行删除操作。新的慢查询日志会直接覆盖旧的查询日志，不需要再手动删除。数据库管理员也可以手工删除慢查询日志，删除之后需要重新启动 MySQL 服务。{message type="warning" content="注意：通用查询日志和慢查询日志都是使用这个命令，使用时一定要注意，一旦执行这个命令，通用查询日志和慢查询日志都只存在新的日志文件中。如果需要备份旧的慢查询日志文件，必须先将旧的日志改名，然后重启 MySQL 服务或执行 mysqladmin 命令。"/}

MySQL的增删改查 1、关于库的增删改查增CREATE DATABASE 库名称; #-----------------=====----------------- CREATE DATABASE shool CHARSET utf8mb4 COLLATE utf8mb4_bin;删DROP DATABASE 数据库;改#修改数据库编码 ALTER DATABASE 数据库 CHARSET 编码;查SHOW DATABASES; #查看所有数据库 SHOW DATABASE 数据库;{mtitle title="关于表的增删改查"/}增增加表单：create table 表名称(字段1 数据类型,字段2 数据类型........限制条件); #至少有一股字段和数据类型,最后一个字段已经最后一个数据类型结束后不加删DREOP TRABLE 数据库; TRUNCATE TABLE 数据库;#清空表里面数据改 字段添加字段:ALTER TABLE 表名称 ADD 字段 字段数据类型; 删除字段:ALTER TABLE 表名称 DROP 字段; 修改字段数据类型:ALTER TABLE 表名称 MODIFY 字段 新的数据类型; 替换字段:ALTER ATBLE 表名称 CHANGE 旧字段名称 新字段 新字段数据类型;　　表改表名称:RENAME TABLE 表名称 TO 新名称; 改表的编码:ALTER TABLE 表名 CHARSET 新编码;查查看所有表:SHOW TABLES; 查看指定表信息:DESC TABLE 表名称; 查看指定表创建信息:SHOW CREATE TABLE 表名称;{mtitle title="对于表的数据进行增删"/}增插入一个值INSERT INTO 表名 VALUES(v1,v2,....) # 该方式必须保证 插入的数据个数与 表格字段一 一对应 INSERT INTO 表名(字段名称1,字段名称2) VALUES(v1,v2) # 该方式必须保证 插入的数据个数与 必须与指插入多个值INSERT INTO 表名 VALUES(v1),(v2) INSERT INTO 表名(字段名称1,字段名称2) VALUES(v1,v1),(v2,v2)删删除所有:DELETE FROM 表名; 删除指定条件下:DELETE FROM 表名 WHERE 条件;改修改所有数据:UPDATE 表名 SET 字段名称=新的值,字段名称2=值2; 修改满足条件的数据:UPDATE 表名 SET 字段名称=新的值,字段名称2=值2 WHERE 条件查查看所有字段:SELECT * FROM 表名; 查看指定字段:SELECT 字段 FROM 表名 ; 查看某个条件所有的字段:SELECT * FROM 表名 WHERE 条件; 查看某个条件下的某个字段:SELECT 字段 FROM 表名 WHERE 条件;

编译安装MySQL5.7 1.MySQL源码包获取在MySQL官网下载你需要的二进制包版本。官网下载链接：https://downloads.mysql.com/archives/community/本文是以mysql-5.7.28版本为例，所以也可以直接下载我这个版本。链接：https://cdn.mysql.com/archives/mysql-5.7/mysql-boost-5.7.28.tar.gz2.编译安装MySQL2.1 下载源码包wget https://cdn.mysql.com/archives/mysql-5.7/mysql-boost-5.7.28.tar.gz2.2 安装依赖yum -y install gcc gcc-c++ cmake openssl openssl-devel ncurses-devel autoconf2.3 解压源码包tar xf mysql-boost-5.7.28.tar.gz2.4 创建程序目录mkdir -p /application2.5 预编译和编译安装预编译，生成Makefile文件cd mysql-5.7.28 cmake . -DCMAKE_INSTALL_PREFIX=/application/mysql-5.7.28 \ -DMYSQL_DATADIR=/application/mysql-5.7.28/data \ -DMYSQL_UNIX_ADDR=/application/mysql-5.7.28/tmp/mysql.sock \ -DDOWNLOAD_BOOST=1 \ -DWITH_BOOST=./boost/boost_1_59_0/ \ -DDEFAULT_CHARSET=utf8 \ -DDEFAULT_COLLATION=utf8_general_ci \ -DWITH_EXTRA_CHARSETS=all \ -DWITH_INNOBASE_STORAGE_ENGINE=1 \ -DWITH_FEDERATED_STORAGE_ENGINE=1 \ -DWITH_BLACKHOLE_STORAGE_ENGINE=1 \ -DWITHOUT_EXAMPLE_STORAGE_ENGINE=1 \ -DWITH_ZLIB=bundled \ -DWITH_SSL=system \ -DENABLED_LOCAL_INFILE=1 \ -DWITH_EMBEDDED_SERVER=1 \ -DENABLE_DOWNLOADS=1 \ -DWITH_DEBUG=0 编译安装make && make install2.6 创建软连接(也可以直接复制过去)ln -s /application/mysql-5.7.28/ /application/mysql2.7 创建数据库管理用户useradd -M -s /sbin/nologin mysql2.8 授权数据库目录chown -R mysql.mysql /application/mysql-5.7.28/ chown -R mysql.mysql /application/mysql/2.9 拷贝配置文件和启动脚本cp /application/mysql/support-files/mysql.server /etc/init.d/mysqld2.10 编写配置文件[root@db05 ~]# vim /etc/my.cnf [mysqld] datadir=/application/mysql/data socket=/application/mysql/tmp/mysql.sock [client] socket=/application/mysql/tmp/mysql.sock2.11 创建相关目录，并授权mkdir /application/mysql/{tmp,log} chown -R mysql:mysql /application/mysql2.12 初始化数据库初始化/application/mysql/bin/mysqld --initialize --user=mysql --basedir=/application/mysql --datadir=/application/mysql/data获取密码初始化成功后，在命令行输出的最后一行会显示密码3.启动数据库3.1 使用启动脚本启动mysql启动/etc/init.d/mysqld start关闭/etc/init.d/mysqld stop3.2 使用systemd管理mysql服务新建一个mysql服务的unit文件[root@db02 ~]# vim /usr/lib/systemd/system/mysqld.service [Unit] Description=MySQL Server Documentation=man:mysqld(8) Documentation=https://dev.mysql.com/doc/refman/en/using-systemd.html After=network.target After=syslog.target [Install] WantedBy=multi-user.target [Service] User=mysql Group=mysql ExecStart=/application/mysql/bin/mysqld --defaults-file=/etc/my.cnf LimitNOFILE = 5000重载系统的unit文件systemctl daemon-reload启动服务systemctl start mysqld3.3 检查mysql服务是否启动查看mysql的进程[root@db02 ~]# ps -ef | grep [m]ysql mysql 42951 1 0 14:48 ? 00:00:00 /application/mysql/bin/mysqld --defaults-file=/etc/my.cnf查看端口[root@db02 ~]# netstat -lntp | grep 3306 tcp6 0 0 :::3306 :::* LISTEN 42951/mysqld 3.4 登录数据库使用绝对路径登录[root@db02 ~]# /application/msyql/bin/msyql配置环境变量，直接使用mysql命令因为系统中/usr/bin/或者/usr/sbin/目录下默认是mysql的命令的，修改下PATH变量，让其可以直接使用mysql命令添加环境变量脚本echo "export PATH=/application/mysql/bin:\$PATH" > /etc/profile.d/mysql.sh #重新加载环境变量 source /etc/profile登录mysql[root@db02 ~]# mysql -uroot -p

Shell for循环和select循环语句 for循环格式for 变量名 in 变量取值列表 do 指令 done示例打印5 4 3 2 1 5个数字#!/bin/bash for i in 5 4 3 2 1 do echo $i done 方法二 #!/bin/bash for (( i=5;i>0;i--)) do echo $i done PS:改名命令rename命令jpg格式的图片改成pngrename ".jpg" ".png" "*.jpg"打印九九乘法表#!/bin/bash for num1 in `seq 9` do for num2 in `seq 9` do if [ $num1 -ge $num2 ];then if ((($num1*$num2)>9)) ;then echo -en "${num1}x${num2}=$((num1*num2)) " else echo -en "${num1}x${num2}=$((num1*num2)) " fi fi done echo " " done计算1-100的和#!/bin/bash for ((i=1;i<=100;i++)) do ((sum=sum+$i)) done echo "$sum"select循环语句select 变量名 [ in 菜单取值列表] do 指令 done示例:select 循环打印简单菜单项 1、直接使用列表字符串#!/bin/bash select name in zhansan lisi wanger do echo $name done2、采用数组作为变量打印#!/bin/bash array=(zhansan lisi wanger) select $name in "${array[@]}" do echo "$name" done#!/bin/bash PS3="please select a num from menu:" #PS3是select循环的提示符 select name in zhansan lisi wanger do echo -e "I guess you selected the menu is:\n $REPLY) $name" #REPLY变量是菜单项对应的数字 done示例打印选择菜单 ，选择一键安装不同Web服务1.[install lamp] 2.[install lnmp] 3.[exit]#!/bin/bash RETVAR=0 path=/server/scripts #定义脚本路径 [ ! -d "$path" ] && mkdir $path -p #如果不存在就创建 function Usage() { echo "Usage :$0 argv" return 1 } function InstallService() { if [ $# -ne 1 ]; then Usage fi local RETVAR=0 echo "start installing ${1}." sleep 2 if [ ! -x "$path/${1}.sh" ]; then echo "$path/${1}.sh 没有执行权限" return 1 else $path/${1}.sh return $RETVAR fi } function main() { PS3="please input the num you want:" select num in "Install lamp" "Install lnmp" "exit" do case "$num" in "Install lamp") InstallService lamp RETVAR=$? ;; "Install lnmp") InstallService lnmp RETVAR=$? ;; exit) echo bye. return 3 ;; *) echo "the num you input must be {1|2|3}" echo "Input error" esac done echo $ RETVAR } main

MySQL常用命令 mysql常用命令有：1、“create database name;”；2、“use databasename;”；3、“drop database name”；4、“show tables;”；5、“select version”等等。 推荐：《mysql视频教程》MySQL 数据库常用命令1、MySQL常用命令create database name; 创建数据库 use databasename; 选择数据库 drop database name; 直接删除数据库，不提醒 show tables; 显示表 describe tablename; 表的详细描述 select 中加上distinct去除重复字段 mysqladmin drop databasename; 删除数据库前，有提示。 显示当前mysql版本和当前日期 select version(),current_date;2、修改mysql中root的密码：mysql -u root -p mysql> update user set password=password("123456") where user='root'; mysql> flush privileges; //刷新数据库 mysql> use dbname; 打开数据库： mysql> show databases; 显示所有数据库 mysql> show tables; 显示数据库mysql中所有的表：先use mysql；然后 mysql>describe user; 显示表mysql数据库中user表的列信息）；3、grant创建一个可以从任何地方连接服务器的一个完全的超级用户，但是必须使用一个口令something做这个mysql> grant all privileges on *.* to user@localhost identified by '密码' with;增加新用户格式：grant select on 数据库.* to 用户名@登录主机 identified by “密码” GRANT ALL PRIVILEGES ON *.* TO 用户名@localhost IDENTIFIED BY '密码' WITH GRANT OPTION; GRANT ALL PRIVILEGES ON *.* TO 用户名@"%" IDENTIFIED BY '密码' WITH GRANT OPTION;删除授权：mysql> revoke all privileges on *.* from root@"%"; mysql> delete from user where user=”root” and host="%"; mysql> flush privileges;创建一个用户custom在特定客户端it363.com登录，可访问特定数据库fangchandbmysql >grant select, insert, update, delete, create,drop on fangchandb.* to custom@ it363.com identified by 'passwd';重命名表:mysql > alter table t1 rename t2;4、mysqldump备份数据库mysqldump -h host -u root -p dbname >dbname_backup.sql恢复数据库mysqladmin -h myhost -u root -p create dbname mysqldump -h host -u root -p dbname < dbname_backup.sql如果只想卸出建表指令，则命令如下：mysqladmin -u root -p -d databasename > a.sql如果只想卸出插入数据的sql命令，而不需要建表命令，则命令如下：mysqladmin -u root -p -t databasename > a.sql那么如果我只想要数据，而不想要什么sql命令时，应该如何操作呢？mysqldump -T./ phptest driver其中，只有指定了-T参数才可以卸出纯文本文件，表示卸出数据的目录，./表示当前目录，即与mysqldump同一目录。如果不指定driver 表，则将卸出整个数据库的数据。每个表会生成两个文件，一个为.sql文件，包含建表执行。另一个为.txt文件，只包含数据，且没有sql指令。5、可将查询存储在一个文件中并告诉mysql从文件中读取查询而不是等待键盘输入。可利用外壳程序键入重定向实用程序来完成这项工作。例如，如果在文件my_file.sql 中存放有查询，可如下执行这些查询：例如，如果您想将建表语句提前写在sql.txt中:mysql > mysql -h myhost -u root -p database < sql.txt;

Typecho 手机端评论失败解决方法 　今天无意中发现了个BUG，就是评论的时候，偶尔会出现评论失败的情况，这个情况我之前碰到过，没写教程:@(高兴)，它的情况就是在在QQ内打开博客后无法评论，但是在浏览器里面又正常，所以这里记录一下,主要的问题就是修改typecho_comments表里agent字段，调整agent字段容量，调大一点，好开始操作　phpMyAdmin进入数据库后找到需要操作的数据库，展开后看到typecho_comments表，点击右边的结构之后找到agent字段之后点击右边的修改，在里面找到长度/值将默认的数值改成500之后保存就OK了，是不是很简单，没懂的可以看下面的动图操作或者用下面命令也可以ALTER TABLE typecho_comments modify column agent varchar(500);