If you are doing a backup on the server, and your tables all are
MyISAM
tables, consider using the
mysqlhotcopy
instead because it can accomplish faster backups and faster restores. See
mysqlhotcopy(1).

There are three general ways to invoke
mysqldump:

shell> mysqldump [options] db_name [tables]

shell> mysqldump [options] ––databases db_name1 [db_name2 db_name3...]

shell> mysqldump [options] ––all–databases

If you do not name any tables following
db_name
or if you use the
––databases
or
––all–databases
option, entire databases are dumped.

To get a list of the options your version of
mysqldump
supports, execute
mysqldump ––help.

If you run
mysqldump
without the
––quick
or
––opt
option,
mysqldump
loads the whole result set into memory before dumping the result. This can be a problem if you are dumping a big database. The
––opt
option is enabled by default, but can be disabled with
––skip–opt.

If you are using a recent copy of the
mysqldump
program to generate a dump to be reloaded into a very old MySQL server, you should not use the
––opt
or
––extended–insert
option. Use
––skip–opt
instead.

mysqldump
supports the following options:

*

––help,
–?

Display a help message and exit.

*

––add–drop–database

Add a
DROP DATABASE
statement before each
CREATE DATABASE
statement.

*

––add–drop–table

Add a
DROP TABLE
statement before each
CREATE TABLE
statement.

*

––add–locks

Surround each table dump with
LOCK TABLES
and
UNLOCK TABLES
statements. This results in faster inserts when the dump file is reloaded. See
Section 2.16, lqSpeed of INSERT Statementsrq.

*

––all–databases,
–A

Dump all tables in all databases. This is the same as using the
––databases
option and naming all the databases on the command line.

*

––allow–keywords

Allow creation of column names that are keywords. This works by prefixing each column name with the table name.

*

––character–sets–dir=path

The directory where character sets are installed. See
Section 9.1, lqThe Character Set Used for Data and Sortingrq.

*

––comments,
–i

Write additional information in the dump file such as program version, server version, and host. . This option is enabled by default. To suppress additional, use
––skip–comments.

*

––compact

Produce less verbose output. This option suppresses comments and enables the
––skip–add–drop–table,
––no–set–names,
––skip–disable–keys, and
––skip–add–locks
options.

*

––compatible=name

Produce output that is more compatible with other database systems or with older MySQL servers. The value of
name
can be
ansi,
mysql323,
mysql40,
postgresql,
oracle,
mssql,
db2,
maxdb,
no_key_options,
no_table_options, or
no_field_options. To use several values, separate them by commas. These values have the same meaning as the corresponding options for setting the server SQL mode. See
the section called lqTHE SERVER SQL MODErq.

This option does not guarantee compatibility with other servers. It only enables those SQL mode values that are currently available for making dump output more compatible. For example,
––compatible=oracle
does not map data types to Oracle types or use Oracle comment syntax.

*

––complete–insert,
–c

Use complete
INSERT
statements that include column names.

*

––compress,
–C

Compress all information sent between the client and the server if both support compression.

*

––create–options

Include all MySQL–specific table options in the
CREATE TABLE
statements.

*

––databases,
–B

Dump several databases. Normally,
mysqldump
treats the first name argument on the command line as a database name and following names as table names. With this option, it treats all name arguments as database names.
CREATE DATABASE
and
USE
statements are included in the output before each new database.

*

––debug[=debug_options],
–# [debug_options]

Write a debugging log. The
debug_options
string is often
‘d:t:o,file_name‘. The default is
‘d:t:o,/tmp/mysqldump.trace’.

*

––default–character–set=charset_name

Use
charset_name
as the default character set. See
Section 9.1, lqThe Character Set Used for Data and Sortingrq. If not specified,
mysqldump
uses
utf8.

*

––delayed–insert

Write
INSERT DELAYED
statements rather than
INSERT
statements.

*

––delete–master–logs

On a master replication server, delete the binary logs after performing the dump operation. This option automatically enables
––master–data.

*

––disable–keys,
–K

For each table, surround the
INSERT
statements with
/*!40000 ALTER TABLE tbl_name DISABLE KEYS */;
and
/*!40000 ALTER TABLE tbl_name ENABLE KEYS */;
statements. This makes loading the dump file faster because the indexes are created after all rows are inserted. This option is effective for
MyISAM
tables only.

*

––extended–insert,
–e

Use multiple–row
INSERT
syntax that include several
VALUES
lists. This results in a smaller dump file and speeds up inserts when the file is reloaded.

*

––fields–terminated–by=…,
––fields–enclosed–by=…,
––fields–optionally–enclosed–by=…,
––fields–escaped–by=…,
––lines–terminated–by=…

These options are used with the
–T
option and have the same meaning as the corresponding clauses for
LOAD DATA INFILE. See
Section 2.5, lqLOAD DATA INFILE Syntaxrq.

*

––first–slave,
–x

Deprecated. Now renamed to
––lock–all–tables.

*

––flush–logs,
–F

Flush the MySQL server log files before starting the dump. This option requires the
RELOAD
privilege. Note that if you use this option in combination with the
––all–databases
(or
–A) option, the logs are flushed
for each database dumped. The exception is when using
––lock–all–tables
or
––master–data: In this case, the logs are flushed only once, corresponding to the moment that all tables are locked. If you want your dump and the log flush to happen at exactly the same moment, you should use
––flush–logs
together with either
––lock–all–tables
or
––master–data.

*

––force,
–f

Continue even if an SQL error occurs during a table dump.

*

––host=host_name,
–h host_name

Dump data from the MySQL server on the given host. The default host is
localhost.

*

––hex–blob

Dump binary columns using hexadecimal notation (for example,
‘abc’
becomes
0×616263). The affected data types are
BINARY,
VARBINARY, and
BLOB. As of MySQL 5.0.13,
BIT
columns are affected as well.

*

––ignore–table=db_name.tbl_name

Do not dump the given table, which must be specified using both the database and table names. To ignore multiple tables, use this option multiple times.

*

––insert–ignore

Write
INSERT
statements with the
IGNORE
option.

*

––lock–all–tables,
–x

Lock all tables across all databases. This is achieved by acquiring a global read lock for the duration of the whole dump. This option automatically turns off
––single–transaction
and
––lock–tables.

*

––lock–tables,
–l

Lock all tables before starting the dump. The tables are locked with
READ LOCAL
to allow concurrent inserts in the case of
MyISAM
tables. For transactional tables such as
InnoDB
and
BDB,
––single–transaction
is a much better option, because it does not need to lock the tables at all.

Please note that when dumping multiple databases,
––lock–tables
locks tables for each database separately. So, this option does not guarantee that the tables in the dump file are logically consistent between databases. Tables in different databases may be dumped in completely different states.

*

––master–data[=value]

Write the binary log filename and position to the output. This option requires the
RELOAD
privilege and the binary log must be enabled. If the option value is equal to 1, the position and filename are written to the dump output in the form of a
CHANGE MASTER
statement that makes a slave server start from the correct position in the master’s binary logs if you use this SQL dump of the master to set up a slave. If the option value is equal to 2, the
CHANGE MASTER
statement is written as an SQL comment. This is the default action if
value
is omitted.

The
––master–data
option turns on
––lock–all–tables, unless
––single–transaction
also is specified (in which case, a global read lock is only acquired a short time at the beginning of the dump. See also the description for
––single–transaction. In all cases, any action on logs happens at the exact moment of the dump. This option automatically turns off
––lock–tables.

*

––no–autocommit

Enclose the
INSERT
statements for each dumped table within
SET AUTOCOMMIT=0
and
COMMIT
statements.

*

––no–create–db,
–n

This option suppresses the
CREATE DATABASE
statements that are otherwise included in the output if the
––databases
or
––all–databases
option is given.

*

––no–create–info,
–t

Do not write
CREATE TABLE
statements that re–create each dumped table.

*

––no–data,
–d

Do not write any row information for the table. This is very useful if you want to dump only the
CREATE TABLE
statement for the table.

*

––opt

This option is shorthand; it is the same as specifying
––add–drop–table ––add–locks ––create–options ––disable–keys ––extended–insert ––lock–tables ––quick ––set–charset. It should give you a fast dump operation and produce a dump file that can be reloaded into a MySQL server quickly.

The ––opt option is enabled by default. To disable the options that it enables, use ––skip–opt. To disable only certain of the options enabled by
––opt, use their
––skip
forms; for example,
––skip–add–drop–table
or
––skip–quick.

*

––order–by–primary

Sorts each table’s rows by its primary key, or its first unique index, if such an index exists. This is useful when dumping a
MyISAM
table to be loaded into an
InnoDB
table, but will make the dump itself take considerably longer.

*

––password[=password],
–p[password]

The password to use when connecting to the server. If you use the short option form (–p), you
cannot
have a space between the option and the password. If you omit the
password
value following the
––password
or
–p
option on the command line, you are prompted for one.

Specifying a password on the command line should be considered insecure. See
Section 7.6, lqKeeping Your Password Securerq.

*

––port=port_num,
–P port_num

The TCP/IP port number to use for the connection.

*

––protocol={TCP|SOCKET|PIPE|MEMORY}

The connection protocol to use.

*

––quick,
–q

This option is useful for dumping large tables. It forces
mysqldump
to retrieve rows for a table from the server a row at a time rather than retrieving the entire row set and buffering it in memory before writing it out.

*

––quote–names,
–Q

Quote database, table, and column names within oq`cq characters. If the
ANSI_QUOTES
SQL mode is enabled, names are quoted within oq”cq characters. This option is enabled by default. It can be disabled with
––skip–quote–names, but this option should be given after any option such as
––compatible
that may enable
––quote–names.

*

––result–file=file,
–r file

Direct output to a given file. This option should be used on Windows to prevent newline oq\ncq characters from being converted to oq\r\ncq carriage return/newline sequences.

*

––routines,
–R

Dump stored routines (functions and procedures) from the dumped databases. The output generated by using
––routines
contains
CREATE PROCEDURE
and
CREATE FUNCTION
statements to re–create the routines. However, these statements do not include attributes such as the routine creation and modification timestamps. This means that when the routines are reloaded, they will be created with the timestamps equal to the reload time.

If you require routines to be re–created with their original timestamp attributes, do not use
––routines. Instead, dump and reload the contents of the
mysql.proc
table directly, using a MySQL account that has appropriate privileges for the
mysql
database.

This option was added in MySQL 5.0.13. Before that, stored routines are not dumped. Routine
DEFINER
values are not dumped until MySQL 5.0.20. This means that before 5.0.20, when routines are reloaded, they will be created with the definer set to the reloading user. If you require routines to be re–created with their original definer, dump and load the contents of the
mysql.proc
table directly as described earlier.

*

––set–charset

Add
SET NAMES default_character_set
to the output. This option is enabled by default. To suppress the
SET NAMES
statement, use
––skip–set–charset.

*

––single–transaction

This option issues a
BEGIN
SQL statement before dumping data from the server. It is useful only with transactional tables such as
InnoDB
and
BDB, because then it dumps the consistent state of the database at the time when
BEGIN
was issued without blocking any applications.

When using this option, you should keep in mind that only
InnoDB
tables are dumped in a consistent state. For example, any
MyISAM
or
MEMORY
tables dumped while using this option may still change state.

The
––single–transaction
option and the
––lock–tables
option are mutually exclusive, because
LOCK TABLES
causes any pending transactions to be committed implicitly.

To dump big tables, you should combine this option with
––quick.

*

––socket=path,
–S path

For connections to
localhost, the Unix socket file to use, or, on Windows, the name of the named pipe to use.

*

––skip–comments

See the description for the
––comments
option.

*

––ssl*

Options that begin with
––ssl
specify whether to connect to the server via SSL and indicate where to find SSL keys and certificates. See
Section 7.7.3, lqSSL Command Optionsrq.

*

––tab=path,
–T path

Produce tab–separated data files. For each dumped table,
mysqldump
creates a
tbl_name.sql
file that contains the
CREATE TABLE
statement that creates the table, and a
tbl_name.txt
file that contains its data. The option value is the directory in which to write the files.

By default, the
.txt
data files are formatted using tab characters between column values and a newline at the end of each line. The format can be specified explicitly using the
––fields–xxx
and
––lines––xxx
options.

Note: This option should be used only when
mysqldump
is run on the same machine as the
mysqld
server. You must have the
FILE
privilege, and the server must have permission to write files in the directory that you specify.

*

––tables

Override the
––databases
or
–B
option. All name arguments following the option are regarded as table names.

*

––triggers

Dump triggers for each dumped table. This option is enabled by default; disable it with
––skip–triggers. This option was added in MySQL 5.0.11. Before that, triggers are not dumped.

*

––tz–utc

Add
SET TIME_ZONE=’+00:00′
to the dump file so that
TIMESTAMP
columns can be dumped and reloaded between servers in different time zones. Without this option,
TIMESTAMP
columns are dumped and reloaded in the time zones local to the source and destination servers, which can cause the values to change.
––tz–utc
also protects against changes due to daylight saving time.
––tz–utc
is enabled by default. To disable it, use
––skip–tz–utc. This option was added in MySQL 5.0.15.

*

––user=user_name,
–u user_name

The MySQL username to use when connecting to the server.

*

––verbose,
–v

Verbose mode. Print more information about what the program does.

*

––version,
–V

Display version information and exit.

*

––where=’where_condition‘,
–w ‘where_condition‘

Dump only rows selected by the given
WHERE
condition. Note that quotes around the condition are mandatory if it contains spaces or other characters that are special to your command interpreter.

Examples:

––where=”user=’jimf’”

–w”userid>1″

–w”userid<1″

*

––xml,
–X

Write dump output as well–formed XML.

You can also set the following variables by using
––var_name=value
syntax:

*

max_allowed_packet

The maximum size of the buffer for client/server communication. The maximum is 1GB.

*

net_buffer_length

The initial size of the buffer for client/server communication. When creating multiple–row–insert statements (as with option
––extended–insert
or
––opt),
mysqldump
creates rows up to
net_buffer_length
length. If you increase this variable, you should also ensure that the
net_buffer_length
variable in the MySQL server is at least this large.

It is also possible to set variables by using
––set–variable=var_name=value
or
–O var_name=value
syntax.
This syntax is deprecated.

The most common use of
mysqldump
is probably for making a backup of an entire database:

shell> mysqldump ––opt db_name > backup–file.sql

You can read the dump file back into the server like this:

shell> mysql db_name < backup–file.sql

Or like this:

shell> mysql –e “source /path–to–backup/backup–file.sql” db_name

mysqldump
is also very useful for populating databases by copying data from one MySQL server to another:

shell> mysqldump ––opt db_name | mysql ––host=remote_host –C db_name

It is possible to dump several databases with one command:

shell> mysqldump ––databases db_name1 [db_name2 ...] > my_databases.sql

To dump all databases, use the
––all–databases
option:

shell> mysqldump ––all–databases > all_databases.sql

For
InnoDB
tables,
mysqldump
provides a way of making an online backup:

shell> mysqldump ––all–databases ––single–transaction > all_databases.sql

This backup just needs to acquire a global read lock on all tables (using
FLUSH TABLES WITH READ LOCK) at the beginning of the dump. As soon as this lock has been acquired, the binary log coordinates are read and the lock is released. If and only if one long updating statement is running when the
FLUSH
statement is issued, the MySQL server may get stalled until that long statement finishes, and then the dump becomes lock–free. If the update statements that the MySQL server receives are short (in terms of execution time), the initial lock period should not be noticeable, even with many updates.

For point–in–time recovery (also known as
lqroll–forward,rq
when you need to restore an old backup and replay the changes that happened since that backup), it is often useful to rotate the binary log (see
Section 10.3, lqThe Binary Logrq) or at least know the binary log coordinates to which the dump corresponds:

shell> mysqldump ––all–databases ––master–data=2 > all_databases.sql

Or:

shell> mysqldump ––all–databases ––flush–logs ––master–data=2

              > all_databases.sql

The simultaneous use of
––master–data
and
––single–transaction
provides a convenient way to make an online backup suitable for point–in–time recovery if tables are stored in the
InnoDB
storage engine.

For more information on making backups, see
Section 8.1, lqDatabase Backupsrq, and
Section 8.2, lqExample Backup and Recovery Strategyrq.

SEE ALSO

msql2mysql(1),
myisam_ftdump(1),
myisamchk(1),
myisamlog(1),
myisampack(1),
mysql(1),
mysql.server(1),
mysql_config(1),
mysql_fix_privilege_tables(1),
mysql_upgrade(1),
mysql_zap(1),
mysqlaccess(1),
mysqladmin(1),
mysqlbinlog(1),
mysqlcheck(1),
mysqld(1),
mysqld_multi(1),
mysqld_safe(1),
mysqlhotcopy(1),
mysqlimport(1),
mysqlmanager(1),
mysqlshow(1),
perror(1),
replace(1),
safe_mysqld(1)

For more information, please refer to the MySQL Reference Manual,
which may already be installed locally and which is also available
online at http://dev.mysql.com/doc/.

AUTHOR

MySQL AB (http://www.mysql.com/).
This software comes with no warranty.

Index

NAME

SYNOPSIS

DESCRIPTION

SEE ALSO

AUTHOR