mysqldump - Unix, Linux Command
NAME
mysqldump - a database backup program
SYNOPSIS
Tag | Description |
mysqldump [options] [db_name [tbl_name ...]]
|
DESCRIPTION
The
mysqldump
client is a backup program originally written by Igor Romanenko. It can be used to dump a database or a collection of databases for backup or transfer to another SQL server (not necessarily a MySQL server). The dump typically contains SQL statements to create the table, populate it, or both. However,
mysqldump
can also be used to generate files in CSV, other delimited text, or XML format.
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 [tbl_name ...]
shell> mysqldump [options] --databases db_name ...
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.
mysqldump
does not dump the
INFORMATION_SCHEMA
database by default. As of MySQL 5.1.38,
mysqldump
dumps
INFORMATION_SCHEMA
if you name it explicitly on the command line, although you must also use the
--skip-lock-tables
option. Before 5.1.38,
mysqldump
silently ignores
INFORMATION_SCHEMA
even if you name it explicitly on the command line.
In MySQL Cluster NDB 7.1.7 and later, the
ndbinfo
information database is ignored and not dumped by
mysqldump.
To see a list of the options your version of
mysqldump
supports, execute
mysqldump --help.
Some
mysqldump
options are shorthand for groups of other options:
o
Tag | Description |
o
|
Use of
--opt
is the same as specifying
--add-drop-table,
--add-locks,
--create-options,
--disable-keys,
--extended-insert,
--lock-tables,
--quick, and
--set-charset. All of the options that
--opt
stands for also are on by default because
--opt
is on by default.
|
o
Tag | Description |
o
|
Use of
--compact
is the same as specifying
--skip-add-drop-table,
--skip-add-locks,
--skip-comments,
--skip-disable-keys, and
--skip-set-charset
options.
|
To reverse the effect of a group option, uses its
--skip-xxx
form (--skip-opt
or
--skip-compact). It is also possible to select only part of the effect of a group option by following it with options that enable or disable specific features. Here are some examples:
o
Tag | Description |
o
|
To select the effect of
--opt
except for some features, use the
--skip
option for each feature. To disable extended inserts and memory buffering, use
--opt
--skip-extended-insert
--skip-quick. (Actually,
--skip-extended-insert
--skip-quick
is sufficient because
--opt
is on by default.)
|
o
Tag | Description |
o
|
To reverse
--opt
for all features except index disabling and table locking, use
--skip-opt
--disable-keys
--lock-tables.
|
When you selectively enable or disable the effect of a group option, order is important because options are processed first to last. For example,
--disable-keys
--lock-tables
--skip-opt
would not have the intended effect; it is the same as
--skip-opt
by itself.
mysqldump
can retrieve and dump table contents row by row, or it can retrieve the entire content from a table and buffer it in memory before dumping it. Buffering in memory can be a problem if you are dumping large tables. To dump tables row by row, use the
--quick
option (or
--opt, which enables
--quick). The
--opt
option (and hence
--quick) is enabled by default, so to enable memory buffering, use
--skip-quick.
If you are using a recent version of
mysqldump
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.
Note
mysqldump
from MySQL 5.1.21 cannot be used to create dumps from MySQL server 5.1.20 and older. This issue is fixed in MySQL 5.1.22. ([blue]Bug#30123[][1])
mysqldump
supports the following options, which can be specified on the command line or in the
[mysqldump]
and
[client]
option file groups.
mysqldump
also supports the options for processing option files described at
Section 4.2.3.3.1, Command-Line Options that Affect Option-File Handling\(rq.
o
Tag | Description |
o
|
--help,
-?
Display a help message and exit.
|
o
Tag | Description |
o
|
--add-drop-database
Add a
DROP DATABASE
statement before each
CREATE DATABASE
statement. This option is typically used in conjunction with the
--all-databases
or
--databases
option because no
CREATE DATABASE
statements are written unless one of those options is specified.
|
o
Tag | Description |
o
|
--add-drop-table
Add a
DROP TABLE
statement before each
CREATE TABLE
statement.
|
o
Tag | Description |
o
|
--add-drop-trigger
Add a
DROP TRIGGER
statement before each
CREATE TRIGGER
statement.
Tag | Description |
|
Note
This option is supported only by
mysqldump
as supplied with MySQL Cluster NDB 6.3.38, MySQL Cluster NDB 7.0.19, MySQL Cluster NDB 7.1.8, and later MySQL Cluster release. It is not available when using MySQL 5.1.
|
|
o
Tag | Description |
o
|
--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 7.3.2.1, \(lqSpeed of INSERT Statements\(rq.
|
o
Tag | Description |
o
|
--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.
|
o
Tag | Description |
o
|
--all-tablespaces,
-Y
Adds to a table dump all SQL statements needed to create any tablespaces used by an
NDBCLUSTER
table. This information is not otherwise included in the output from
mysqldump. This option is currently relevant only to MySQL Cluster tables.
This option was added in MySQL 5.1.6.
|
o
Tag | Description |
o
|
--allow-keywords
Permit creation of column names that are keywords. This works by prefixing each column name with the table name.
|
o
Tag | Description |
o
|
--bind-address=ip_address
On a computer having multiple network interfaces, this option can be used to select which interface is employed when connecting to the MySQL server.
This option is supported only in the version of
mysqldump
that is supplied with MySQL Cluster, beginning with MySQL Cluster NDB 6.3.4. It is not available in standard MySQL 5.1 releases.
|
o
Tag | Description |
o
|
--character-sets-dir=path
The directory where character sets are installed. See
Section 9.5, \(lqCharacter Set Configuration\(rq.
|
o
Tag | Description |
o
|
--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 this additional information, use
--skip-comments.
|
o
Tag | Description |
o
|
--compact
Produce more compact output. This option enables the
--skip-add-drop-table,
--skip-add-locks,
--skip-comments,
--skip-disable-keys, and
--skip-set-charset
options.
Tag | Description |
|
Note
Prior to MySQL 5.1.21, this option did not create valid SQL if the database dump contained views. The recreation of views requires the creation and removal of temporary tables and this option suppressed the removal of those temporary tables. As a workaround, use
--compact
with the
--add-drop-table
option and then manually adjust the dump file.
|
|
o
Tag | Description |
o
|
--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
Section 5.1.7, \(lqServer SQL Modes\(rq.
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.
This option requires a server version of 4.1.0 or higher. With older servers, it does nothing.
|
o
Tag | Description |
o
|
--complete-insert,
-c
Use complete
INSERT
statements that include column names.
|
o
Tag | Description |
o
|
--compress,
-C
Compress all information sent between the client and the server if both support compression.
|
o
Tag | Description |
o
|
--create-options
Include all MySQL-specific table options in the
CREATE TABLE
statements.
|
o
Tag | Description |
o
|
--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.
|
o
Tag | Description |
o
|
--debug[=debug_options],
-# [debug_options]
Write a debugging log. A typical
debug_options
string is
'd:t:o,file_name'. The default value is
'd:t:o,/tmp/mysqldump.trace'.
|
o
Tag | Description |
o
|
--debug-check
Print some debugging information when the program exits. This option was added in MySQL 5.1.21.
|
o
Tag | Description |
o
|
--debug-info
Print debugging information and memory and CPU usage statistics when the program exits. This option was added in MySQL 5.1.14.
|
o
Tag | Description |
o
|
--default-character-set=charset_name
Use
charset_name
as the default character set. See
Section 9.5, \(lqCharacter Set Configuration\(rq. If no character set is specified,
mysqldump
uses
utf8, and earlier versions use
latin1.
Prior to MySQL 5.1.38, this option has no effect for output data files produced by using the
--tab
option. See the description for that option.
|
o
Tag | Description |
o
|
--delayed-insert
Write
INSERT DELAYED
statements rather than
INSERT
statements.
|
o
Tag | Description |
o
|
--delete-master-logs
On a master replication server, delete the binary logs by sending a
PURGE BINARY LOGS
statement to the server after performing the dump operation. This option automatically enables
--master-data.
|
o
Tag | Description |
o
|
--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 only for nonunique indexes of
MyISAM
tables.
|
o
Tag | Description |
o
|
--dump-date
If the
--comments
option is given,
mysqldump
produces a comment at the end of the dump of the following form:
Tag | Description |
|
-- Dump completed on DATE
|
|
However, the date causes dump files taken at different times to appear to be different, even if the data are otherwise identical.
--dump-date
and
--skip-dump-date
control whether the date is added to the comment. The default is
--dump-date
(include the date in the comment).
--skip-dump-date
suppresses date printing. This option was added in MySQL 5.1.23.
|
o
Tag | Description |
o
|
--events,
-E
Include Event Scheduler events for the dumped databases in the output. This option was added in MySQL 5.1.8.
|
o
Tag | Description |
o
|
--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.
|
o
Tag | Description |
o
|
--fields-terminated-by=...,
--fields-enclosed-by=...,
--fields-optionally-enclosed-by=...,
--fields-escaped-by=...
These options are used with the
--tab
option and have the same meaning as the corresponding
FIELDS
clauses for
LOAD DATA INFILE. See
Section 12.2.6, \(lqLOAD DATA INFILE Syntax\(rq.
|
o
Tag | Description |
o
|
--first-slave
Deprecated. Use
--lock-all-tables
instead.
--first-slave
is removed in MySQL 5.5.
|
o
Tag | Description |
o
|
--flush-logs,
-F
Flush the MySQL server log files before starting the dump. This option requires the
RELOAD
privilege. If you use this option in combination with the
--all-databases
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.
|
o
Tag | Description |
o
|
--flush-privileges
Send a
FLUSH PRIVILEGES
statement to the server 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 restoration. This option was added in MySQL 5.1.12.
|
o
Tag | Description |
o
|
--force,
-f
Continue even if an SQL error occurs during a table dump.
One use for this option is to cause
mysqldump
to continue executing even when it encounters a view that has become invalid because the definition refers to a table that has been dropped. Without
--force,
mysqldump
exits with an error message. With
--force,
mysqldump
prints the error message, but it also writes an SQL comment containing the view definition to the dump output and continues executing.
|
o
Tag | Description |
o
|
--host=host_name,
-h host_name
Dump data from the MySQL server on the given host. The default host is
localhost.
|
o
Tag | Description |
o
|
--hex-blob
Dump binary columns using hexadecimal notation (for example,
'abc'
becomes
0x616263). The affected data types are
BINARY,
VARBINARY, the
BLOB
types, and
BIT.
|
o
Tag | Description |
o
|
--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. This option also can be used to ignore views.
|
o
Tag | Description |
o
|
--insert-ignore
Write
INSERT IGNORE
statements rather than
INSERT
statements.
|
o
Tag | Description |
o
|
--lines-terminated-by=...
This option is used with the
--tab
option and has the same meaning as the corresponding
LINES
clause for
LOAD DATA INFILE. See
Section 12.2.6, \(lqLOAD DATA INFILE Syntax\(rq.
|
o
Tag | Description |
o
|
--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.
|
o
Tag | Description |
o
|
--lock-tables,
-l
For each dumped database, lock all tables to be dumped before dumping them. The tables are locked with
READ LOCAL
to permit concurrent inserts in the case of
MyISAM
tables. For transactional tables such as
InnoDB,
--single-transaction
is a much better option than
--lock-tables
because it does not need to lock the tables at all.
Because
--lock-tables
locks tables for each database separately, 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.
|
o
Tag | Description |
o
|
--log-error=file_name
Log warnings and errors by appending them to the named file. The default is to do no logging. This option was added in MySQL 5.1.18.
|
o
Tag | Description |
o
|
--master-data[=value]
Use this option to dump a master replication server to produce a dump file that can be used to set up another server as a slave of the master. It causes the dump output to include a
CHANGE MASTER TO
statement that indicates the binary log coordinates (file name and position) of the dumped server. These are the master server coordinates from which the slave should start replicating after you load the dump file into the slave.
If the option value is 2, the
CHANGE MASTER TO
statement is written as an SQL comment, and thus is informative only; it has no effect when the dump file is reloaded. If the option value is 1, the statement is not written as a comment and takes effect when the dump file is reloaded. If no option value is specified, the default value is 1.
This option requires the
RELOAD
privilege and the binary log must be enabled.
The
--master-data
option automatically turns off
--lock-tables. It also turns on
--lock-all-tables, unless
--single-transaction
also is specified, in which case, a global read lock is acquired only for a short time at the beginning of the dump (see the description for
--single-transaction). In all cases, any action on logs happens at the exact moment of the dump.
It is also possible to set up a slave by dumping an existing slave of the master. To do this, use the following procedure on the existing slave:
Tag | Description |
|
1.
Tag | Description |
1.
|
Stop the slave's SQL thread and get its current status:
|
Tag | Description |
|
mysql> STOP SLAVE SQL_THREAD;
mysql> SHOW SLAVE STATUS;
|
|
|
Tag | Description |
|
2.
Tag | Description |
2.
|
From the output of the
SHOW SLAVE STATUS
statement, the binary log coordinates of the master server from which the new slave should start replicating are the values of the
Relay_Master_Log_File
and
Exec_Master_Log_Pos
fields. Denote those values as
file_name
and
file_pos.
|
|
Tag | Description |
|
3.
Tag | Description |
3.
|
Dump the slave server:
|
Tag | Description |
|
shell> mysqldump --master-data=2 --all-databases > dumpfile
|
|
|
Tag | Description |
|
4.
Tag | Description |
4.
|
Restart the slave:
|
|
Tag | Description |
|
5.
Tag | Description |
5.
|
On the new slave, load the dump file:
|
|
Tag | Description |
|
6.
Tag | Description |
6.
|
On the new slave, set the replication coordinates to those of the master server obtained earlier:
|
Tag | Description |
|
mysql> CHANGE MASTER TO
-> MASTER_LOG_FILE = 'file_name', MASTER_LOG_POS = file_pos;
|
|
The
CHANGE MASTER TO
statement might also need other parameters, such as
MASTER_HOST
to point the slave to the correct master server host. Add any such parameters as necessary.
|
|
o
Tag | Description |
o
|
--no-autocommit
Enclose the
INSERT
statements for each dumped table within
SET autocommit = 0
and
COMMIT
statements.
|
o
Tag | Description |
o
|
--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.
|
o
Tag | Description |
o
|
--no-create-info,
-t
Do not write
CREATE TABLE
statements that re-create each dumped table.
Tag | Description |
|
Note
This option does
not
not exclude statements creating log file groups or tablespaces from
mysqldump
output; in MySQL 5.1.14 and later, you can use the
--no-tablespaces
option for this purpose.
|
|
o
Tag | Description |
o
|
--no-data,
-d
Do not write any table row information (that is, do not dump table contents). This is useful if you want to dump only the
CREATE TABLE
statement for the table (for example, to create an empty copy of the table by loading the dump file).
|
o
Tag | Description |
o
|
--no-set-names,
-N
This has the same effect as
--skip-set-charset.
|
o
Tag | Description |
o
|
--no-tablespaces,
-y
This option suppresses all
CREATE LOGFILE GROUP
and
CREATE TABLESPACE
statements in the output of
mysqldump.
This option was added in MySQL 5.1.14.
|
o
Tag | Description |
o
|
--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. Use --skip-opt to disable it.
See the discussion at the beginning of this section for information about selectively enabling or disabling a subset of the options affected by
--opt.
|
o
Tag | Description |
o
|
--order-by-primary
Dump each table's rows sorted by its primary key, or by 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 operation take considerably longer.
|
o
Tag | Description |
o
|
--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,
mysqldump
prompts for one.
Specifying a password on the command line should be considered insecure. See
Section 5.3.2.2, \(lqEnd-User Guidelines for Password Security\(rq. You can use an option file to avoid giving the password on the command line.
|
o
Tag | Description |
o
|
--pipe,
-W
On Windows, connect to the server using a named pipe. This option applies only if the server supports named-pipe connections.
|
o
Tag | Description |
o
|
--port=port_num,
-P port_num
The TCP/IP port number to use for the connection.
|
o
Tag | Description |
o
|
--protocol={TCP|SOCKET|PIPE|MEMORY}
The connection protocol to use for connecting to the server. It is useful when the other connection parameters normally would cause a protocol to be used other than the one you want. For details on the permissible values, see
Section 4.2.2, \(lqConnecting to the MySQL Server\(rq.
|
o
Tag | Description |
o
|
--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.
|
o
Tag | Description |
o
|
--quote-names,
-Q
Quote identifiers (such as database, table, and column names) within
\(lq\(rq
characters. If the
ANSI_QUOTES
SQL mode is enabled, identifiers are quoted within
\(lq"\(rq
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.
|
o
Tag | Description |
o
|
--replace
Write
REPLACE
statements rather than
INSERT
statements. This option was added in MySQL 5.1.3.
|
o
Tag | Description |
o
|
--result-file=file_name,
-r file_name
Direct output to a given file. This option should be used on Windows to prevent newline
\(lq\n\(rq
characters from being converted to
\(lq\r\n\(rq
carriage return/newline sequences. The result file is created and its previous contents overwritten, even if an error occurs while generating the dump.
|
o
Tag | Description |
o
|
--routines,
-R
Included stored routines (procedures and functions) for the dumped databases in the output. Use of this option requires the
SELECT
privilege for the
mysql.proc
table. 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 5.1.2. Before that, stored routines are not dumped. Routine
DEFINER
values are not dumped until MySQL 5.1.8. This means that before 5.1.8, 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.
|
o
Tag | Description |
o
|
--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.
|
o
Tag | Description |
o
|
--single-transaction
This option sends a
START TRANSACTION
SQL statement to the server before dumping data. It is useful only with transactional tables such as
InnoDB, 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.
While a
--single-transaction
dump is in process, to ensure a valid dump file (correct table contents and binary log coordinates), no other connection should use the following statements:
ALTER TABLE,
CREATE TABLE,
DROP TABLE,
RENAME TABLE,
TRUNCATE TABLE. A consistent read is not isolated from those statements, so use of them on a table to be dumped can cause the
SELECT
that is performed by
mysqldump
to retrieve the table contents to obtain incorrect contents or fail.
The
--single-transaction
option and the
--lock-tables
option are mutually exclusive because
LOCK TABLES
causes any pending transactions to be committed implicitly.
This option is not supported for MySQL Cluster tables; the results cannot be guaranteed to be consistent due to the fact that the
NDBCLUSTER
storage engine supports only the
READ_COMMITTED
transaction isolation level. You should always use
NDB
backup and restore instead.
To dump large tables, you should combine the
--single-transaction
option with
--quick.
|
o
Tag | Description |
o
|
--skip-comments
See the description for the
--comments
option.
|
o
Tag | Description |
o
|
--skip-opt
See the description for the
--opt
option.
|
o
Tag | Description |
o
|
--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.
|
o
Tag | Description |
o
|
--ssl*
Options that begin with
--ssl
specify whether to connect to the server using SSL and indicate where to find SSL keys and certificates. See
Section 5.5.6.3, \(lqSSL Command Options\(rq.
|
o
Tag | Description |
o
|
--tab=path,
-T path
Produce tab-separated text-format data files. For each dumped table,
mysqldump
creates a
tbl_name.sql
file that contains the
CREATE TABLE
statement that creates the table, and the server writes a
tbl_name.txt
file that contains its data. The option value is the directory in which to write the files.
Tag | Description |
|
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.
|
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-terminated-by
options.
As of MySQL 5.1.38, column values are converted to the character set specified by the
--default-character-set
option. Prior to 5.1.38 or if no such option is present, values are dumped using the
binary
character set. In effect, there is no character set conversion. If a table contains columns in several character sets, the output data file will as well and you may not be able to reload the file correctly.
|
o
Tag | Description |
o
|
--tables
Override the
--databases
or
-B
option.
mysqldump
regards all name arguments following the option as table names.
|
o
Tag | Description |
o
|
--triggers
Include triggers for each dumped table in the output. This option is enabled by default; disable it with
--skip-triggers.
|
o
Tag | Description |
o
|
--tz-utc
This option enables
TIMESTAMP
columns to be dumped and reloaded between servers in different time zones.
mysqldump
sets its connection time zone to UTC and adds
SET TIME_ZONE='+00:00'
to the dump file. 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 if the servers are in different time zones.
--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 5.1.2.
|
o
Tag | Description |
o
|
--user=user_name,
-u user_name
The MySQL user name to use when connecting to the server.
|
o
Tag | Description |
o
|
--verbose,
-v
Verbose mode. Print more information about what the program does.
|
o
Tag | Description |
o
|
--version,
-V
Display version information and exit.
|
o
Tag | Description |
o
|
--where='where_condition',
-w 'where_condition'
Dump only rows selected by the given
WHERE
condition. Quotes around the condition are mandatory if it contains spaces or other characters that are special to your command interpreter.
Examples:
Tag | Description |
|
--where="user='jimf'"
-w"userid>1"
-w"userid<1"
|
|
|
o
Tag | Description |
o
|
--xml,
-X
Write dump output as well-formed XML.
NULL, 'NULL', and Empty Values: For a column named
column_name, the
NULL
value, an empty string, and the string value
'NULL'
are distinguished from one another in the output generated by this option as follows.
Value
| XML Representation
|
NULL (unknown value)
| <field name="column_name" xsi nil="true" />
|
'' (empty string)
| <field name="column_name"></field>
|
'NULL' (string value)
| <field name="column_name">NULL</field>
|
Beginning with MySQL 5.1.12, the output from the
mysql
client when run using the
--xml
option also follows the preceding rules. (See
the section called \(lqMYSQL OPTIONS\(rq.)
Beginning with MySQL 5.1.18, XML output from
mysqldump
includes the XML namespace, as shown here:
Tag | Description |
|
shell> mysqldump --xml -u root world City
<?xml version="1.0"?>
<mysqldump xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<database name="world">
<table_structure name="City">
<field Field="ID" Type="int(11)" Null="NO" Key="PRI" Extra="auto_increment" />
<field Field="Name" Type="char(35)" Null="NO" Key="" Default="" Extra="" />
<field Field="CountryCode" Type="char(3)" Null="NO" Key="" Default="" Extra="" />
<field Field="District" Type="char(20)" Null="NO" Key="" Default="" Extra="" />
<field Field="Population" Type="int(11)" Null="NO" Key="" Default="0" Extra="" />
<key Table="City" Non_unique="0" Key_name="PRIMARY" Seq_in_index="1" Column_name="ID"
Collation="A" Cardinality="4079" Null="" Index_type="BTREE" Comment="" />
<options Name="City" Engine="MyISAM" Version="10" Row_format="Fixed" Rows="4079"
Avg_row_length="67" Data_length="273293" Max_data_length="18858823439613951"
Index_length="43008" Data_free="0" Auto_increment="4080"
Create_time="2007-03-31 01:47:01" Update_time="2007-03-31 01:47:02"
Collation="latin1_swedish_ci" Create_options="" Comment="" />
</table_structure>
<table_data name="City">
<row>
<field name="ID">1</field>
<field name="Name">Kabul</field>
<field name="CountryCode">AFG</field>
<field name="District">Kabol</field>
<field name="Population">1780000</field>
</row>
...
<row>
<field name="ID">4079</field>
<field name="Name">Rafah</field>
<field name="CountryCode">PSE</field>
<field name="District">Rafah</field>
<field name="Population">92020</field>
</row>
</table_data>
</database>
</mysqldump>
|
|
|
You can also set the following variables by using
--var_name=value
syntax:
o
Tag | Description |
o
|
max_allowed_packet
The maximum size of the buffer for client/server communication. The maximum is 1GB.
|
o
Tag | Description |
o
|
net_buffer_length
The initial size of the buffer for client/server communication. When creating multiple-row
INSERT
statements (as with the
--extended-insert
or
--opt
option),
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.
|
A common use of
mysqldump
is for making a backup of an entire database:
shell> mysqldump db_name > backup-file.sql
|
You can load 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 acquires 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 long updating statements are running when the
FLUSH
statement is issued, the MySQL server may get stalled until those statements finish. After that, the dump becomes lock free and does not disturb reads and writes on the tables. 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 5.2.4, \(lqThe Binary Log\(rq) 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
--master-data
and
--single-transaction
options can be used simultaneously, which provides a convenient way to make an online backup suitable for use prior to point-in-time recovery if tables are stored using the
InnoDB
storage engine.
For more information on making backups, see
Section 6.2, \(lqDatabase Backup Methods\(rq, and
Section 6.3, \(lqExample Backup and Recovery Strategy\(rq.
If you encounter problems backing up views, please read the section that covers restrictions on views which describes a workaround for backing up views when this fails due to insufficient privileges. See
Section E.4, \(lqRestrictions on Views\(rq.
COPYRIGHT
Copyright © 1997, 2011, Oracle and/or its affiliates. All rights reserved.
This documentation is free software; you can redistribute it and/or modify it only under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License.
This documentation is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with the program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or see http://www.gnu.org/licenses/.
NOTES
SEE ALSO
which may already be installed locally and which is also available
online at http://dev.mysql.com/doc/.
AUTHOR
Oracle Corporation (http://dev.mysql.com/).
|