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
Section 4.6.9, “mysqlhotcopy — A Database Backup Program”.
There are three general ways to invoke mysqldump:
shell>mysqldump [shell>options]db_name[tbl_name...]mysqldump [shell>options] --databasesdb_name...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.
mysqldump dumps
INFORMATION_SCHEMA only if you name it
explicitly on the command line, although currently you must also
use the
--skip-lock-tables
option. Before MySQL 5.5
mysqldump silently ignores
INFORMATION_SCHEMA even if you name it
explicitly on the command line.
mysqldump does not dump the
performance_schema database.
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:
Use of
--optis 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--optstands for also are on by default because--optis on by default.Use of
--compactis the same as specifying--skip-add-drop-table,--skip-add-locks,--skip-comments,--skip-disable-keys, and--skip-set-charsetoptions.
To reverse the effect of a group option, uses its
--skip- form
(xxx--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:
To select the effect of
--optexcept for some features, use the--skipoption for each feature. To disable extended inserts and memory buffering, use--opt--skip-extended-insert--skip-quick. (Actually,--skip-extended-insert--skip-quickis sufficient because--optis on by default.)To reverse
--optfor 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.
For additional information about mysqldump, see Section 6.4, “Using mysqldump for Backups”.
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”.
Table 4.5. mysqldump Options
| Format | Option File | Description | Introduction | Deprecated | Removed |
|---|---|---|---|---|---|
| --add-drop-database | add-drop-database | Add a DROP DATABASE statement before each CREATE DATABASE statement | |||
| --add-drop-table | add-drop-table | Add a DROP TABLE statement before each CREATE TABLE statement | |||
| --add-locks | add-locks | Surround each table dump with LOCK TABLES and UNLOCK TABLES statements | |||
| --all-databases | all-databases | Dump all tables in all databases | |||
| --allow-keywords | allow-keywords | Allow creation of column names that are keywords | |||
| --apply-slave-statements | apply-slave-statements | Include STOP SLAVE prior to CHANGE MASTER statement and START SLAVE at end of output | 5.5.3 | ||
| --bind-address=ip_address | bind-address | Use the specified network interface to connect to the MySQL Server | 5.5.8 | ||
| --comments | comments | Add comments to the dump file | |||
| --compact | compact | Produce more compact output | |||
| --compatible=name[,name,...] | compatible | Produce output that is more compatible with other database systems or with older MySQL servers | |||
| --complete-insert | complete-insert | Use complete INSERT statements that include column names | |||
| --create-options | create-options | Include all MySQL-specific table options in CREATE TABLE statements | |||
| --databases | databases | Dump several databases | |||
| --debug[=debug_options] | debug | Write a debugging log | |||
| --debug-check | debug-check | Print debugging information when the program exits | |||
| --debug-info | debug-info | Print debugging information, memory and CPU statistics when the program exits | |||
| --default-auth=plugin | default-auth=plugin | The authentication plugin to use | 5.5.9 | ||
| --default-character-set=charset_name | default-character-set | Use charset_name as the default character set | |||
| --delayed-insert | delayed-insert | Write INSERT DELAYED statements rather than INSERT statements | |||
| --delete-master-logs | delete-master-logs | On a master replication server, delete the binary logs after performing the dump operation | |||
| --disable-keys | disable-keys | For each table, surround the INSERT statements with statements to disable and enable keys | |||
| --dump-date | dump-date | Include dump date as "Dump completed on" comment if --comments is given | |||
| --dump-slave[=value] | dump-slave | Include CHANGE MASTER statement that lists binary log coordinates of slave's master | 5.5.3 | ||
| --events | events | Dump events from the dumped databases | |||
| --extended-insert | extended-insert | Use multiple-row INSERT syntax that include several VALUES lists | |||
| --fields-enclosed-by=string | fields-enclosed-by | This option is used with the --tab option and has the same meaning as the corresponding clause for LOAD DATA INFILE | |||
| --fields-escaped-by | fields-escaped-by | This option is used with the --tab option and has the same meaning as the corresponding clause for LOAD DATA INFILE | |||
| --fields-optionally-enclosed-by=string | fields-optionally-enclosed-by | This option is used with the --tab option and has the same meaning as the corresponding clause for LOAD DATA INFILE | |||
| --fields-terminated-by=string | fields-terminated-by | This option is used with the --tab option and has the same meaning as the corresponding clause for LOAD DATA INFILE | |||
| --first-slave | first-slave | Deprecated; use --lock-all-tables instead | 5.5.3 | ||
| --flush-logs | flush-logs | Flush the MySQL server log files before starting the dump | |||
| --flush-privileges | flush-privileges | Emit a FLUSH PRIVILEGES statement after dumping the mysql database | |||
| --help | Display help message and exit | ||||
| --hex-blob | hex-blob | Dump binary columns using hexadecimal notation (for example, 'abc' becomes 0x616263) | |||
| --host | host | Host to connect to (IP address or hostname) | |||
| --ignore-table=db_name.tbl_name | ignore-table | Do not dump the given table | |||
| --include-master-host-port | include-master-host-port | Include MASTER_HOST/MASTER_PORT options in CHANGE MASTER statement produced with --dump-slave | 5.5.3 | ||
| --insert-ignore | insert-ignore | Write INSERT IGNORE statements rather than INSERT statements | |||
| --lines-terminated-by=string | lines-terminated-by | This option is used with the --tab option and has the same meaning as the corresponding clause for LOAD DATA INFILE | |||
| --lock-all-tables | lock-all-tables | Lock all tables across all databases | |||
| --lock-tables | lock-tables | Lock all tables before dumping them | |||
| --log-error=file_name | log-error | Append warnings and errors to the named file | |||
| --master-data[=value] | master-data | Write the binary log file name and position to the output | |||
| --max_allowed_packet=value | max_allowed_packet | The maximum packet length to send to or receive from the server | |||
| --net_buffer_length=value | net_buffer_length | The buffer size for TCP/IP and socket communication | |||
| --no-autocommit | no-autocommit | Enclose the INSERT statements for each dumped table within SET autocommit = 0 and COMMIT statements | |||
| --no-create-db | no-create-db | This option suppresses the CREATE DATABASE statements | |||
| --no-create-info | no-create-info | Do not write CREATE TABLE statements that re-create each dumped table | |||
| --no-data | no-data | Do not dump table contents | |||
| --no-set-names | no-set-names | Same as --skip-set-charset | |||
| --no-tablespaces | no-tablespaces | Do not write any CREATE LOGFILE GROUP or CREATE TABLESPACE statements in output | |||
| --opt | opt | Shorthand for --add-drop-table --add-locks --create-options --disable-keys --extended-insert --lock-tables --quick --set-charset. | |||
| --order-by-primary | order-by-primary | Dump each table's rows sorted by its primary key, or by its first unique index | |||
| --password[=password] | password | The password to use when connecting to the server | |||
| --pipe | On Windows, connect to server using a named pipe | ||||
| --plugin-dir=path | plugin-dir=path | The directory where plugins are located | 5.5.9 | ||
| --port=port_num | port | The TCP/IP port number to use for the connection | |||
| --quick | quick | Retrieve rows for a table from the server a row at a time | |||
| --quote-names | quote-names | Quote identifiers within backtick characters | |||
| --replace | replace | Write REPLACE statements rather than INSERT statements | |||
| --result-file=file | result-file | Direct output to a given file | |||
| --routines | routines | Dump stored routines (procedures and functions) from the dumped databases | |||
| --set-charset | set-charset | Add SET NAMES default_character_set to the output | |||
| --single-transaction | single-transaction | This option issues a BEGIN SQL statement before dumping data from the server | |||
| --skip-add-drop-table | skip-add-drop-table | Do not add a DROP TABLE statement before each CREATE TABLE statement | |||
| --skip-add-locks | skip-add-locks | Do not add locks | |||
| --skip-comments | skip-comments | Do not add comments to the dump file | |||
| --skip-compact | skip-compact | Do not produce more compact output | |||
| --skip-disable-keys | skip-disable-keys | Do not disable keys | |||
| --skip-extended-insert | skip-extended-insert | Turn off extended-insert | |||
| --skip-opt | skip-opt | Turn off the options set by --opt | |||
| --skip-quick | skip-quick | Do not retrieve rows for a table from the server a row at a time | |||
| --skip-quote-names | skip-quote-names | Do not quote identifiers | |||
| --skip-set-charset | skip-set-charset | Suppress the SET NAMES statement | |||
| --skip-triggers | skip-triggers | Do not dump triggers | |||
| --skip-tz-utc | skip-tz-utc | Turn off tz-utc | |||
| --ssl-ca=file_name | ssl-ca | The path to a file that contains a list of trusted SSL CAs | |||
| --ssl-capath=directory_name | ssl-capath | The path to a directory that contains trusted SSL CA certificates in PEM format | |||
| --ssl-cert=file_name | ssl-cert | The name of the SSL certificate file to use for establishing a secure connection | |||
| --ssl-cipher=cipher_list | ssl-cipher | A list of allowable ciphers to use for SSL encryption | |||
| --ssl-key=file_name | ssl-key | The name of the SSL key file to use for establishing a secure connection | |||
| --ssl-verify-server-cert | ssl-verify-server-cert | The server's Common Name value in its certificate is verified against the host name used when connecting to the server | |||
| --tab=path | tab | Produce tab-separated data files | |||
| --tables | tables | Override the --databases or -B option | |||
| --triggers | triggers | Dump triggers for each dumped table | |||
| --tz-utc | tz-utc | Add SET TIME_ZONE='+00:00' to the dump file | |||
| --user=user_name | user | The MySQL user name to use when connecting to the server | |||
| --verbose | Verbose mode | ||||
| --version | Display version information and exit | ||||
| --where='where_condition' | where | Dump only rows selected by the given WHERE condition | |||
| --xml | xml | Produce XML output |
--help,-?Display a help message and exit.
Add a
DROP DATABASEstatement before eachCREATE DATABASEstatement. This option is typically used in conjunction with the--all-databasesor--databasesoption because noCREATE DATABASEstatements are written unless one of those options is specified.Add a
DROP TABLEstatement before eachCREATE TABLEstatement.Surround each table dump with
LOCK TABLESandUNLOCK TABLESstatements. This results in faster inserts when the dump file is reloaded. See Section 7.2.2.1, “Speed ofINSERTStatements”.--all-databases,-ADump all tables in all databases. This is the same as using the
--databasesoption and naming all the databases on the command line.Adds to a table dump all SQL statements needed to create any tablespaces used by an
NDBCLUSTERtable. This information is not otherwise included in the output from mysqldump. This option is currently relevant only to MySQL Cluster tables.Permit creation of column names that are keywords. This works by prefixing each column name with the table name.
For a slave dump produced with the
--dump-slaveoption, add aSTOP SLAVEstatement before theCHANGE MASTER TOstatement and aSTART SLAVEstatement at the end of the output. This option was added in MySQL 5.5.3.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 beginning with MySQL 5.5.8.
The directory where character sets are installed. See Section 9.5, “Character Set Configuration”.
--comments,-iWrite 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.Produce more compact output. This option enables the
--skip-add-drop-table,--skip-add-locks,--skip-comments,--skip-disable-keys, and--skip-set-charsetoptions.Produce output that is more compatible with other database systems or with older MySQL servers. The value of
namecan beansi,mysql323,mysql40,postgresql,oracle,mssql,db2,maxdb,no_key_options,no_table_options, orno_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, “Server SQL Modes”.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=oracledoes 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.
Use complete
INSERTstatements that include column names.--compress,-CCompress all information sent between the client and the server if both support compression.
Include all MySQL-specific table options in the
CREATE TABLEstatements.--databases,-BDump 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 DATABASEandUSEstatements are included in the output before each new database.--debug[=,debug_options]-# [debug_options]Write a debugging log. A typical
debug_optionsstring is'd:t:o,. The default value isfile_name''d:t:o,/tmp/mysqldump.trace'.Print some debugging information when the program exits.
Print debugging information and memory and CPU usage statistics when the program exits.
The client-side authentication plugin to use. See Section 5.5.6, “Pluggable Authentication”.
This option was added in MySQL 5.5.9.
--default-character-set=charset_nameUse
charset_nameas the default character set. See Section 9.5, “Character Set Configuration”. If no character set is specified, mysqldump usesutf8, and earlier versions uselatin1.Write
INSERT DELAYEDstatements rather thanINSERTstatements.On a master replication server, delete the binary logs by sending a
PURGE BINARY LOGSstatement to the server after performing the dump operation. This option automatically enables--master-data.--disable-keys,-KFor each table, surround the
INSERTstatements with/*!40000 ALTER TABLEandtbl_nameDISABLE KEYS */;/*!40000 ALTER TABLEstatements. 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 oftbl_nameENABLE KEYS */;MyISAMtables.If the
--commentsoption is given, mysqldump produces a comment at the end of the dump of the following form:-- Dump completed on
DATEHowever, the date causes dump files taken at different times to appear to be different, even if the data are otherwise identical.
--dump-dateand--skip-dump-datecontrol whether the date is added to the comment. The default is--dump-date(include the date in the comment).--skip-dump-datesuppresses date printing.This option is similar to
--master-dataexcept that it is used to dump a replication slave server to produce a dump file that can be used to set up another server as a slave that has the same master as the dumped server. It causes the dump output to include aCHANGE MASTER TOstatement that indicates the binary log coordinates (file name and position) of the dumped slave's master (rather than the coordinates of the dumped server, as is done by the--master-dataoption). These are the master server coordinates from which the slave should start replicating. This option was added in MySQL 5.5.3.The option value is handled the same way as for
--master-dataand has the same effect as--master-datain terms of enabling or disabling other options and in how locking is handled.In conjunction with
--dump-slave, the--apply-slave-statementsand--include-master-host-portoptions can also be used.--events,-EInclude Event Scheduler events for the dumped databases in the output.
Use multiple-row
INSERTsyntax that include severalVALUESlists. 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=...These options are used with the
--taboption and have the same meaning as the correspondingFIELDSclauses forLOAD DATA INFILE. See Section 12.2.6, “LOAD DATA INFILESyntax”.Deprecated. Use
--lock-all-tablesinstead.--first-slavewas removed in MySQL 5.5.3.--flush-logs,-FFlush the MySQL server log files before starting the dump. This option requires the
RELOADprivilege. If you use this option in combination with the--all-databasesoption, the logs are flushed for each database dumped. The exception is when using--lock-all-tablesor--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-logstogether with either--lock-all-tablesor--master-data.Send a
FLUSH PRIVILEGESstatement to the server after dumping themysqldatabase. This option should be used any time the dump contains themysqldatabase and any other database that depends on the data in themysqldatabase for proper restoration.--force,-fContinue 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.--host=,host_name-hhost_nameDump data from the MySQL server on the given host. The default host is
localhost.Dump binary columns using hexadecimal notation (for example,
'abc'becomes0x616263). The affected data types areBINARY,VARBINARY, theBLOBtypes, andBIT.For the
CHANGE MASTER TOstatement in a slave dump produced with the--dump-slaveoption, addMASTER_PORTandMASTER_PORToptions for the host name and TCP/IP port number of the slave's master. This option was added in MySQL 5.5.3.--ignore-table=db_name.tbl_nameDo 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.
Write
INSERT IGNOREstatements rather thanINSERTstatements.This option is used with the
--taboption and has the same meaning as the correspondingLINESclause forLOAD DATA INFILE. See Section 12.2.6, “LOAD DATA INFILESyntax”.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-transactionand--lock-tables.--lock-tables,-lFor each dumped database, lock all tables to be dumped before dumping them. The tables are locked with
READ LOCALto permit concurrent inserts in the case ofMyISAMtables. For transactional tables such asInnoDB,--single-transactionis a much better option than--lock-tablesbecause it does not need to lock the tables at all.Because
--lock-tableslocks 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.Log warnings and errors by appending them to the named file. The default is to do no logging.
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 TOstatement 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 TOstatement 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
RELOADprivilege and the binary log must be enabled.The
--master-dataoption automatically turns off--lock-tables. It also turns on--lock-all-tables, unless--single-transactionalso 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:
Stop the slave's SQL thread and get its current status:
mysql>
STOP SLAVE SQL_THREAD;mysql>SHOW SLAVE STATUS;From the output of the
SHOW SLAVE STATUSstatement, the binary log coordinates of the master server from which the new slave should start replicating are the values of theRelay_Master_Log_FileandExec_Master_Log_Posfields. Denote those values asfile_nameandfile_pos.Dump the slave server:
shell>
mysqldump --master-data=2 --all-databases > dumpfileRestart the slave:
mysql>
START SLAVE;On the new slave, load the dump file:
shell>
mysql < dumpfileOn the new slave, set the replication coordinates to those of the master server obtained earlier:
mysql>
CHANGE MASTER TO->MASTER_LOG_FILE = 'file_name', MASTER_LOG_POS =file_pos;The
CHANGE MASTER TOstatement might also need other parameters, such asMASTER_HOSTto point the slave to the correct master server host. Add any such parameters as necessary.
Enclose the
INSERTstatements for each dumped table withinSET autocommit = 0andCOMMITstatements.--no-create-db,-nThis option suppresses the
CREATE DATABASEstatements that are otherwise included in the output if the--databasesor--all-databasesoption is given.--no-create-info,-tDo not write
CREATE TABLEstatements that re-create each dumped table.NoteThis option does not not exclude statements creating log file groups or tablespaces from mysqldump output; however, you can use the
--no-tablespacesoption for this purpose.--no-data,-dDo not write any table row information (that is, do not dump table contents). This is useful if you want to dump only the
CREATE TABLEstatement for the table (for example, to create an empty copy of the table by loading the dump file).--no-set-names,-NThis has the same effect as
--skip-set-charset.--no-tablespaces,-yThis option suppresses all
CREATE LOGFILE GROUPandCREATE TABLESPACEstatements in the output of mysqldump.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
--optoption is enabled by default. Use--skip-optto 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.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
MyISAMtable to be loaded into anInnoDBtable, but will make the dump operation 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 thepasswordvalue following the--passwordor-poption 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, “End-User Guidelines for Password Security”. You can use an option file to avoid giving the password on the command line.
--pipe,-WOn Windows, connect to the server using a named pipe. This option applies only if the server supports named-pipe connections.
The directory in which to look for plugins. It may be necessary to specify this option if the
--default-authoption is used to specify an authentication plugin but mysql does not find it. See Section 5.5.6, “Pluggable Authentication”.This option was added in MySQL 5.5.9.
--port=,port_num-Pport_numThe TCP/IP port number to use for the connection.
--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, “Connecting to the MySQL Server”.
--quick,-qThis 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,-QQuote identifiers (such as database, table, and column names) within “
`” characters. If theANSI_QUOTESSQL mode is enabled, identifiers are quoted within “"” 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--compatiblethat may enable--quote-names.--result-file=,file_name-rfile_nameDirect output to a given file. This option should be used on Windows to prevent newline “
\n” characters from being converted to “\r\n” carriage return/newline sequences. The result file is created and its previous contents overwritten, even if an error occurs while generating the dump.--routines,-RIncluded stored routines (procedures and functions) for the dumped databases in the output. Use of this option requires the
SELECTprivilege for themysql.proctable. The output generated by using--routinescontainsCREATE PROCEDUREandCREATE FUNCTIONstatements 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 themysql.proctable directly, using a MySQL account that has appropriate privileges for themysqldatabase.Add
SET NAMESto the output. This option is enabled by default. To suppress thedefault_character_setSET NAMESstatement, use--skip-set-charset.This option sends a
START TRANSACTIONSQL statement to the server before dumping data. It is useful only with transactional tables such asInnoDB, because then it dumps the consistent state of the database at the time whenBEGINwas issued without blocking any applications.When using this option, you should keep in mind that only
InnoDBtables are dumped in a consistent state. For example, anyMyISAMorMEMORYtables dumped while using this option may still change state.While a
--single-transactiondump 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 theSELECTthat is performed by mysqldump to retrieve the table contents to obtain incorrect contents or fail.The
--single-transactionoption and the--lock-tablesoption are mutually exclusive becauseLOCK TABLEScauses any pending transactions to be committed implicitly.To dump large tables, you should combine the
--single-transactionoption with--quick.See the description for the
--commentsoption.See the description for the
--optoption.--socket=,path-SpathFor connections to
localhost, the Unix socket file to use, or, on Windows, the name of the named pipe to use.Options that begin with
--sslspecify whether to connect to the server using SSL and indicate where to find SSL keys and certificates. See Section 5.5.8.3, “SSL Command Options”.--tab=,path-TpathProduce tab-separated text-format data files. For each dumped table, mysqldump creates a
file that contains thetbl_name.sqlCREATE TABLEstatement that creates the table, and the server writes afile that contains its data. The option value is the directory in which to write the files.tbl_name.txtNoteThis option should be used only when mysqldump is run on the same machine as the mysqld server. You must have the
FILEprivilege, and the server must have permission to write files in the directory that you specify.By default, the
.txtdata 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-andxxx--lines-terminated-byoptions.Column values are converted to the character set specified by the
--default-character-setoption.Override the
--databasesor-Boption. mysqldump regards all name arguments following the option as table names.Include triggers for each dumped table in the output. This option is enabled by default; disable it with
--skip-triggers.This option enables
TIMESTAMPcolumns to be dumped and reloaded between servers in different time zones. mysqldump sets its connection time zone to UTC and addsSET TIME_ZONE='+00:00'to the dump file. Without this option,TIMESTAMPcolumns 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-utcalso protects against changes due to daylight saving time.--tz-utcis enabled by default. To disable it, use--skip-tz-utc.--user=,user_name-uuser_nameThe MySQL user name to use when connecting to the server.
--verbose,-vVerbose mode. Print more information about what the program does.
--version,-VDisplay version information and exit.
--where=',where_condition'-w 'where_condition'Dump only rows selected by the given
WHEREcondition. 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,-XWrite dump output as well-formed XML.
NULL,'NULL', and Empty Values: For a column namedcolumn_name, theNULLvalue, 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>The output from the mysql client when run using the
--xmloption also follows the preceding rules. (See Section 4.5.1.1, “mysql Options”.)XML output from mysqldump includes the XML namespace, as shown here:
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
--
syntax:
var_name=value
The maximum size of the buffer for client/server communication. The maximum is 1GB.
The initial size of the buffer for client/server communication. When creating multiple-row
INSERTstatements (as with the--extended-insertor--optoption), mysqldump creates rows up tonet_buffer_lengthlength. If you increase this variable, you should also ensure that thenet_buffer_lengthvariable 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 “roll-forward,” 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, “The Binary Log”) 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, “Database Backup Methods”, and Section 6.3, “Example Backup and Recovery Strategy”.
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.5, “Restrictions on Views”.