简介
在日常工作中，我们经常需要对MySQL数据库进行一些数据备份，以便在出现数据问题时能够进行恢复。经常使用的方式就是通过mysqldump命令来进行这项工作，今天就来简单介绍些该命令。
msqldump命令
官网地址奉上，可以自行查看：
https://dev.mysql.com/doc/refman/5.7/en/using-mysqldump.html
使用mysqldump命令生成的文件能干什么？
1、可以作为备份，以便在数据丢失的情况下恢复数据。
2、在主从复制中，可以作为设置Slave的数据源。
3、可以作为实验数据的来源：
1）可以作为在不更改原始数据的情况下使用的数据库副本。
2）测试潜在的升级不兼容性。
命令格式
1、 mysqldump -u用户名 -p密码 [OPTIONS] database [tables]
2、 mysqldump -u用户名 -p密码 [OPTIONS] --databases [OPTIONS] DB1 [DB2 DB3...]
3、 mysqldump -u用户名 -p密码 [OPTIONS] --all-databases [OPTIONS]
比如如下示例：将数据库 test进行备份
mysqldump -uroot -p123456 --databases test > test.sql ## 将输出写入test.sql文件
命令很简单，主要还是命令后边携带的参数，参数有很多，常用的参数有如下几个：
-u 用户名
-p 密码
-h hostname 信息
-d（--no-data） 只导出表结构
-A（--all-databases） 备份所有的数据库信息
-B（--databases） 备份多个数据库信息（-B db1 db2 db3 ...）
-Y（--all-tablespaces） 备份所有的表空间信息
-y（--no-tablespaces） 不备份表空间信息
-t（--no-create-info） 不添加 create table 语句 （默认为 开启状态）
-n（--no-create-db） 不添加 create database 语句
--add-drop-table 每次创建表之前先删除存在的表（默认为开启状态）
--skip-add-drop-table 删除 drop table 的语句
如果想了解全部的参数信息，可以使用mysqldump --help 命令查看所有参数信息：
目前只是翻译了部分参数描述，其他的可以自行翻译！
-A, --all-databases 转储所有的数据库.
-Y, --all-tablespaces 转储所有的表空间信息.
-y, --no-tablespaces 不转储任何表空间信息
--add-drop-database 在创建每个数据库之前先添加 DROP DATABASE 语句
--add-drop-table 在创建每个数据表之前先添加 DROP TABLE 语句。
(默认开启; 使用 --skip-add-drop-table 关闭)
--add-drop-trigger 在创建每个触发器之前先添加 DROP TRIGGER 语句。
--add-locks 在INSERT语句周围添加锁表语句。(默认开启; 使用 --skip-add-locks 关闭)
--allow-keywords 允许创建作为关键字的列名。
--apply-slave-statements
Adds 'STOP SLAVE' prior to 'CHANGE MASTER' and 'START
SLAVE' to bottom of dump.
--bind-address=name IP address to bind to.
--character-sets-dir=name
Directory for character set files.
-i, --comments 添加附加信息 (默认开启; 使用 --skip-comments 关闭)
--compatible=name Change the dump to be compatible with a given mode. By
default tables are dumped in a format optimized for
MySQL. Legal modes are: ansi, mysql323, mysql40,
postgresql, oracle, mssql, db2, maxdb, no_key_options,
no_table_options, no_field_options. One can use several
modes separated by commas. Note: Requires MySQL server
version 4.1.0 or higher. This option is ignored with
earlier server versions.
--compact Give less verbose output (useful for debugging). Disables
structure comments and header/footer constructs. Enables
options --skip-add-drop-table --skip-add-locks
--skip-comments --skip-disable-keys --skip-set-charset.
-c, --complete-insert
Use complete insert statements.
-C, --compress Use compression in server/client protocol.
-a, --create-options
Include all MySQL specific create options.
(Defaults to on; use --skip-create-options to disable.)
-B, --databases Dump several databases. Note the difference in usage; in
this case no tables are given. All name arguments are
regarded as database names. 'USE db_name;' will be
included in the output.
-#, --debug[=#] This is a non-debug version. Catch this and exit.
--debug-check This is a non-debug version. Catch this and exit.
--debug-info This is a non-debug version. Catch this and exit.
--default-character-set=name
Set the default character set.
--delete-master-logs
Delete logs on master after backup. This automatically
enables --master-data.
-K, --disable-keys '/*!40000 ALTER TABLE tb_name DISABLE KEYS */; and
'/*!40000 ALTER TABLE tb_name ENABLE KEYS */; will be put
in the output.
(Defaults to on; use --skip-disable-keys to disable.)
--dump-slave[=#] This causes the binary log position and filename of the
master to be appended to the dumped data output. Setting
the value to 1, will printit as a CHANGE MASTER command
in the dumped data output; if equal to 2, that command
will be prefixed with a comment symbol. This option will
turn --lock-all-tables on, unless --single-transaction is
specified too (in which case a global read lock is only
taken a short time at the beginning of the dump - don't
forget to read about --single-transaction below). In all
cases any action on logs will happen at the exact moment
of the dump.Option automatically turns --lock-tables off.
-E, --events Dump events.
-e, --extended-insert
Use multiple-row INSERT syntax that include several
VALUES lists.
(Defaults to on; use --skip-extended-insert to disable.)
--fields-terminated-by=name
Fields in the output file are terminated by the given
string.
--fields-enclosed-by=name
Fields in the output file are enclosed by the given
character.
--fields-optionally-enclosed-by=name
Fields in the output file are optionally enclosed by the
given character.
--fields-escaped-by=name
Fields in the output file are escaped by the given
character.
-F, --flush-logs Flush logs file in server before starting dump. Note that
if you dump many databases at once (using the option
--databases= or --all-databases), the logs will be
flushed for each database dumped. The exception is when
using --lock-all-tables or --master-data: in this case
the logs will be flushed only once, corresponding to the
moment all tables are locked. So if you want your dump
and the log flush to happen at the same exact moment you
should use --lock-all-tables or --master-data with
--flush-logs.
--flush-privileges Emit a FLUSH PRIVILEGES statement after dumping the mysql
database. This option should be used any time the dump
contains the mysql database and any other database that
depends on the data in the mysql database for proper
restore.
-f, --force Continue even if we get an SQL error.
-?, --help Display this help message and exit.
--hex-blob Dump binary strings (BINARY, VARBINARY, BLOB) in
hexadecimal format.
-h, --host=name Connect to host.
--ignore-error=name A comma-separated list of error numbers to be ignored if
encountered during dump.
--ignore-table=name Do not dump the specified table. To specify more than one
table to ignore, use the directive multiple times, once
for each table. Each table must be specified with both
database and table names, e.g.,
--ignore-table=database.table.
--include-master-host-port
Adds 'MASTER_HOST=<host>, MASTER_PORT=<port>' to 'CHANGE
MASTER TO..' in dump produced with --dump-slave.
--insert-ignore Insert rows with INSERT IGNORE.
--lines-terminated-by=name
Lines in the output file are terminated by the given
string.
-x, --lock-all-tables
Locks all tables across all databases. This is achieved
by taking a global read lock for the duration of the
whole dump. Automatically turns --single-transaction and
--lock-tables off.
-l, --lock-tables Lock all tables for read.
(Defaults to on; use --skip-lock-tables to disable.)
--log-error=name Append warnings and errors to given file.
--master-data[=#] This causes the binary log position and filename to be
appended to the output. If equal to 1, will print it as a
CHANGE MASTER command; if equal to 2, that command will
be prefixed with a comment symbol. This option will turn
--lock-all-tables on, unless --single-transaction is
specified too (in which case a global read lock is only
taken a short time at the beginning of the dump; don't
forget to read about --single-transaction below). In all
cases, any action on logs will happen at the exact moment
of the dump. Option automatically turns --lock-tables
off.
--max-allowed-packet=#
The maximum packet length to send to or receive from
server.
--net-buffer-length=#
The buffer size for TCP/IP and socket communication.
--no-autocommit Wrap tables with autocommit/commit statements.
-n, --no-create-db Suppress the CREATE DATABASE ... IF EXISTS statement that
normally is output for each dumped database if
--all-databases or --databases is given.
-t, --no-create-info
Don't write table creation info.
-d, --no-data No row information.
-N, --no-set-names Same as --skip-set-charset.
--opt Same as --add-drop-table, --add-locks, --create-options,
--quick, --extended-insert, --lock-tables, --set-charset,
and --disable-keys. Enabled by default, disable with
--skip-opt.
--order-by-primary Sorts each table's rows by primary key, or first unique
key, if such a key exists. Useful when dumping a MyISAM
table to be loaded into an InnoDB table, but will make
the dump itself take considerably longer.
-p, --password[=name]
Password to use when connecting to server. If password is
not given it's solicited on the tty.
-P, --port=# Port number to use for connection.
--protocol=name The protocol to use for connection (tcp, socket, pipe,
memory).
-q, --quick Don't buffer query, dump directly to stdout.
(Defaults to on; use --skip-quick to disable.)
-Q, --quote-names Quote table and column names with backticks (`).
(Defaults to on; use --skip-quote-names to disable.)
--replace Use REPLACE INTO instead of INSERT INTO.
-r, --result-file=name
Direct output to a given file. This option should be used
in systems (e.g., DOS, Windows) that use carriage-return
linefeed pairs (\r\n) to separate text lines. This option
ensures that only a single newline is used.
-R, --routines Dump stored routines (functions and procedures).
--set-charset Add 'SET NAMES default_character_set' to the output.
(Defaults to on; use --skip-set-charset to disable.)
--set-gtid-purged[=name]
Add 'SET @@GLOBAL.GTID_PURGED' to the output. Possible
values for this option are ON, OFF and AUTO. If ON is
used and GTIDs are not enabled on the server, an error is
generated. If OFF is used, this option does nothing. If
AUTO is used and GTIDs are enabled on the server, 'SET
@@GLOBAL.GTID_PURGED' is added to the output. If GTIDs
are disabled, AUTO does nothing. If no value is supplied
then the default (AUTO) value will be considered.
--single-transaction
Creates a consistent snapshot by dumping all tables in a
single transaction. Works ONLY for tables stored in
storage engines which support multiversioning (currently
only InnoDB does); the dump is NOT guaranteed to be
consistent for other storage engines. While a
--single-transaction dump is in process, to ensure a
valid dump file (correct table contents and binary log
position), no other connection should use the following
statements: ALTER TABLE, DROP TABLE, RENAME TABLE,
TRUNCATE TABLE, as consistent snapshot is not isolated
from them. Option automatically turns off --lock-tables.
--dump-date Put a dump date to the end of the output.
(Defaults to on; use --skip-dump-date to disable.)
--skip-opt Disable --opt. Disables --add-drop-table, --add-locks,
--create-options, --quick, --extended-insert,
--lock-tables, --set-charset, and --disable-keys.
-S, --socket=name The socket file to use for connection.
--secure-auth Refuse client connecting to server if it uses old
(pre-4.1.1) protocol. Deprecated. Always TRUE
--ssl-mode=name SSL connection mode.
--ssl Deprecated. Use --ssl-mode instead.
(Defaults to on; use --skip-ssl to disable.)
--ssl-verify-server-cert
Deprecated. Use --ssl-mode=VERIFY_IDENTITY instead.
--ssl-ca=name CA file in PEM format.
--ssl-capath=name CA directory.
--ssl-cert=name X509 cert in PEM format.
--ssl-cipher=name SSL cipher to use.
--ssl-key=name X509 key in PEM format.
--ssl-crl=name Certificate revocation list.
--ssl-crlpath=name Certificate revocation list path.
--tls-version=name TLS version to use, permitted values are: TLSv1, TLSv1.1,
TLSv1.2
--server-public-key-path=name
File path to the server public RSA key in PEM format.
--get-server-public-key
Get server public key
-T, --tab=name Create tab-separated textfile for each table to given
path. (Create .sql and .txt files.) NOTE: This only works
if mysqldump is run on the same machine as the mysqld
server.
--tables Overrides option --databases (-B).
--triggers Dump triggers for each dumped table.
(Defaults to on; use --skip-triggers to disable.)
--tz-utc SET TIME_ZONE='+00:00' at top of dump to allow dumping of
TIMESTAMP data when a server has data in different time
zones or data is being moved between servers with
different time zones.
(Defaults to on; use --skip-tz-utc to disable.)
-u, --user=name User for login if not current user.
-v, --verbose Print info about the various stages.
-V, --version Output version information and exit.
-w, --where=name Dump only selected records. Quotes are mandatory.
-X, --xml Dump a database as well formed XML.
--plugin-dir=name Directory for client-side plugins.
--default-auth=name Default authentication client-side plugin to use.
--enable-cleartext-plugin
Enable/disable the clear text authentication plugin.