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.

mysqldump requires at least the SELECT privilege for dumped tables, SHOW VIEW for dumped views, SUPER for dumped triggers, and LOCK TABLES if the --single-transaction option is not used. Certain options might require other privileges as noted in the option descriptions.

To reload a dump file, you must have the same privileges needed to create each of the dumped objects by issuing CREATE statements manually.

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 [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. If you name that database explicitly on the command line, mysqldump silently ignores it.

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 --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.

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:

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.)

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.

Before MySQL 4.1.2, out-of-range numeric values such as -inf and inf, as well as NaN (not-a-number) values are dumped by mysqldump as NULL. You can see this using the following sample table:

mysql> CREATE TABLE t (f DOUBLE);
mysql> INSERT INTO t VALUES(1e+111111111111111111111);
mysql> INSERT INTO t VALUES(-1e111111111111111111111);
mysql> SELECT f FROM t;
+------+
| f    |
+------+
|  inf |
| -inf |
+------+
For this table, mysqldump produces the following data output:

--
-- Dumping data for table `t`
--

INSERT INTO t VALUES (NULL);
INSERT INTO t VALUES (NULL);
The significance of this behavior is that if you dump and restore the table, the new table has contents that differ from the original contents. This problem is fixed as of MySQL 4.1.2; you cannot insert inf in the table, so this mysqldump behavior is only relevant when you deal with old servers.

For additional information about mysqldump, see Section 7.4, “Using mysqldump for Backups”.

mysqldump supports the following options, which can be specified on the command line or in the [mysqldump] and [client] groups of an option file. For information about option files used by MySQL programs, see Section 4.2.6, “Using Option Files”.

Table 4.5 mysqldump Options

Format    Description    Introduced
--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     
--all-databases    Dump all tables in all databases     
--allow-keywords    Allow creation of column names that are keywords     
--comments    Add comments to the dump file     
--compact    Produce more compact output     
--compatible=name[,name,...]    Produce output that is more compatible with other database systems or with older MySQL servers     
--complete-insert    Use complete INSERT statements that include column names     
--create-options    Include all MySQL-specific table options in CREATE TABLE statements     
--databases    Dump several databases     
--debug[=debug_options]    Write a debugging log     
--debug-info    Print debugging information, memory, and CPU statistics when program exits    5.0.32
--default-character-set=charset_name    Specify default character set     
--defaults-extra-file=file_name    Read option file in addition to usual option files     
--defaults-file=file_name    Read only named option file     
--defaults-group-suffix=str    Option group suffix value    5.0.10
--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     
--disable-keys    For each table, surround the INSERT statements with statements to disable and enable keys     
--dump-date    Include dump date as "Dump completed on" comment if --comments is given    5.0.52
--extended-insert    Use multiple-row INSERT syntax that include several VALUES lists     
--fields-enclosed-by=string    This option is used with the --tab option and has the same meaning as the corresponding clause for LOAD DATA INFILE     
--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    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    This option is used with the --tab option and has the same meaning as the corresponding clause for LOAD DATA INFILE     
--first-slave    Deprecated; use --lock-all-tables instead     
--flush-logs    Flush the MySQL server log files before starting the dump     
--flush-privileges    Emit a FLUSH PRIVILEGES statement after dumping the mysql database     
--help    Display help message and exit     
--hex-blob    Dump binary columns using hexadecimal notation (for example, ‘abc‘ becomes 0x616263)     
--host    Host to connect to (IP address or hostname)     
--ignore-table=db_name.tbl_name    Do not dump the given table     
--insert-ignore    Write INSERT IGNORE statements rather than INSERT statements     
--lines-terminated-by=string    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 across all databases     
--lock-tables    Lock all tables before dumping them     
--log-error=file_name    Append warnings and errors to the named file    5.0.42
--master-data[=value]    Write the binary log file name and position to the output     
--max_allowed_packet=value    Maximum packet length to send to or receive from server     
--net_buffer_length=value    Buffer size for TCP/IP and socket communication     
--no-autocommit    Enclose the INSERT statements for each dumped table within SET autocommit = 0 and COMMIT statements     
--no-create-db    This option suppresses the CREATE DATABASE statements     
--no-create-info    Do not write CREATE TABLE statements that re-create each dumped table     
--no-data    Do not dump table contents     
--no-defaults    Read no option files     
--no-set-names    Same as --skip-set-charset     
--opt    Shorthand for --add-drop-table --add-locks --create-options --disable-keys --extended-insert --lock-tables --quick --set-charset.     
--order-by-primary    Dump each table‘s rows sorted by its primary key, or by its first unique index     
--password[=password]    Password to use when connecting to server     
--pipe    On Windows, connect to server using named pipe     
--port=port_num    TCP/IP port number to use for connection     
--print-defaults    Print defaults     
--protocol=type    Connection protocol to use     
--quick    Retrieve rows for a table from the server a row at a time     
--quote-names    Quote identifiers within backtick characters     
--result-file=file    Direct output to a given file     
--routines    Dump stored routines (procedures and functions) from the dumped databases    5.0.13
--set-charset    Add SET NAMES default_character_set to output     
--shared-memory-base-name=name    The name of shared memory to use for shared-memory connections     
--single-transaction    This option issues a BEGIN SQL statement before dumping data from the server     
--skip-add-drop-table    Do not add a DROP TABLE statement before each CREATE TABLE statement     
--skip-add-locks    Do not add locks     
--skip-comments    Do not add comments to the dump file     
--skip-compact    Do not produce more compact output     
--skip-disable-keys    Do not disable keys     
--skip-extended-insert    Turn off extended-insert     
--skip-opt    Turn off the options set by --opt     
--skip-quick    Do not retrieve rows for a table from the server a row at a time     
--skip-quote-names    Do not quote identifiers     
--skip-set-charset    Suppress the SET NAMES statement     
--skip-triggers    Do not dump triggers    5.0.11
--skip-tz-utc    Turn off tz-utc    5.0.15
--socket=path    For connections to localhost, the Unix socket file to use     
--ssl    Enable SSL for connection     
--ssl-ca=file_name    Path of file that contains list of trusted SSL CAs     
--ssl-capath=dir_name    Path of directory that contains trusted SSL CA certificates in PEM format     
--ssl-cert=file_name    Path of file that contains X509 certificate in PEM format     
--ssl-cipher=cipher_list    List of permitted ciphers to use for SSL encryption     
--ssl-key=file_name    Path of file that contains X509 key in PEM format     
--ssl-verify-server-cert    Verify server Common Name value in its certificate against host name used when connecting to server    5.0.23
--tab=path    Produce tab-separated data files     
--tables    Override the --databases or -B option     
--triggers    Dump triggers for each dumped table     
--tz-utc    Add SET TIME_ZONE=‘+00:00‘ to the dump file    5.0.15
--user=user_name    MySQL user name to use when connecting to server     
--verbose    Verbose mode     
--version    Display version information and exit     
--where=‘where_condition‘    Dump only rows selected by the given WHERE condition     
--xml    Produce XML output     

 --help, -?

Display a help message and exit.

 --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.

 --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 8.3.2.1, “Speed of INSERT Statements”.

 --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

Permit 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 10.5, “Character Set Configuration”.

 --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.

 --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.

Note
Prior to MySQL 5.0.48, 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.

 --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, “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=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.

 --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. A typical debug_options string is d:t:o,file_name. The default value is d:t:o,/tmp/mysqldump.trace.

 --debug-info

Print debugging information and memory and CPU usage statistics when the program exits. This option was added in MySQL 5.0.32.

 --default-character-set=charset_name

Use charset_name as the default character set. See Section 10.5, “Character Set Configuration”. If no character set is specified, mysqldump uses utf8.

This option has no effect for output data files produced by using the --tab option. See the description for that option.

 --defaults-extra-file=file_name

Read this option file after the global option file but (on Unix) before the user option file. As of MySQL 5.0.6, if the file does not exist or is otherwise inaccessible, an error occurs. file_name is the full path name to the file.

 --defaults-file=file_name

Use only the given option file. If the file does not exist or is otherwise inaccessible, an error occurs. file_name is the full path name to the file.

 --defaults-group-suffix=str

Read not only the usual option groups, but also groups with the usual names and a suffix of str. For example, mysqldump normally reads the [client] and [mysqldump] groups. If the --defaults-group-suffix=_other option is given, mysqldump also reads the [client_other] and [mysqldump_other] groups. This option was added in MySQL 5.0.10.

 --delayed-insert

Write INSERT DELAYED statements rather than INSERT statements.

 --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.

 --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. It has no effect for other tables.

 --dump-date

If the --comments option is given, mysqldump produces a comment at the end of the dump of the following form:

-- 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 5.0.52.

 --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=...

These options are used with the --tab option and have the same meaning as the corresponding FIELDS clauses for LOAD DATA INFILE. See Section 13.2.6, “LOAD DATA INFILE Syntax”.

 --first-slave

Deprecated. Use --lock-all-tables instead. --first-slave is removed in MySQL 5.5.

 --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.

 --flush-privileges

Add a FLUSH PRIVILEGES statement to the dump output 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 5.0.26.

 --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.

 --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 0x616263). The affected data types are BINARY, VARBINARY, and the BLOB types. 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. This option also can be used to ignore views.

 --insert-ignore

Write INSERT IGNORE statements rather than INSERT statements.

 --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 13.2.6, “LOAD DATA INFILE Syntax”.

 --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

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 and BDB, --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.

 --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 5.0.42.

 --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:

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 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.

Dump the slave server:

shell> mysqldump --master-data=2 --all-databases > dumpfile
Using --master-data=2 works only if binary logging has been enabled on the slave. Otherwise, mysqldump fails with the error Binlogging on server not active. In this case you must handle any locking issues in another manner, using one or more of --add-locks, --lock-tables, --lock-all-tables, or --single-transaction, as required by your application and environment.

Restart the slave:

mysql> START SLAVE;
On the new slave, load the dump file:

shell> mysql < dumpfile
On 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 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.

 --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 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).

 --no-defaults

Do not read any option files. If program startup fails due to reading unknown options from an option file, --no-defaults can be used to prevent them from being read.

 --no-set-names, -N

This has the same effect as --skip-set-charset.

 --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.

 --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.

 --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 6.1.2.1, “End-User Guidelines for Password Security”. You can use an option file to avoid giving the password on the command line.

 --pipe, -W

On Windows, connect to the server using a named pipe. This option applies only if the server supports named-pipe connections.

 --port=port_num, -P port_num

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

 --print-defaults

Print the program name and all options that it gets from option files.

 --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, -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 identifiers (such as database, table, and column names) within “`” characters. If the ANSI_QUOTES SQL 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 --compatible that may enable --quote-names.

 --result-file=file_name, -r file_name

Direct 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, -R

Include 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 5.0.13. 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.

 --shared-memory-base-name=name

On Windows, the shared-memory name to use, for connections made using shared memory to a local server. The default value is MYSQL. The shared-memory name is case sensitive.

The server must be started with the --shared-memory option to enable shared-memory connections.

 --single-transaction

This option sets the transaction isolation mode to REPEATABLE READ and sends a START TRANSACTION SQL statement to the server before dumping data. 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 START TRANSACTION 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, combine the --single-transaction option with the --quick option.

 --skip-comments

See the description for the --comments option.

 --skip-opt

See the description for the --opt option.

 --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.

 --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 6.3.6.4, “SSL Command Options”.

 --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.

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.

Column values are dumped using the binary character set and the --default-character-set option is ignored. 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.

 --tables

Override the --databases or -B option. mysqldump regards all name arguments following the option as table names.

 --triggers

Include triggers for each dumped table in the output. 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

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 5.0.15.

 --user=user_name, -u user_name

The MySQL user name 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. 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.

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 5.0.26, the output from the mysql client when run using the --xml option also follows the preceding rules. (See Section 4.5.1.1, “mysql Options”.)

Beginning with MySQL 5.0.40, 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 --var_name=value syntax:

 max_allowed_packet

The maximum size of the buffer for client/server communication. The default is 24MB, 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 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.

It is also possible to set variables by using --var_name=value. The --set-variable format is deprecated.

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 --master-data --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 5.2.3, “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 7.2, “Database Backup Methods”, and Section 7.3, “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 D.4, “Restrictions on Views”.

The mysqlimport client provides a command-line interface to the LOAD DATA INFILE SQL statement. Most options to mysqlimport correspond directly to clauses of LOAD DATA INFILE syntax. See Section 13.2.6, “LOAD DATA INFILE Syntax”.

Invoke mysqlimport like this:

shell> mysqlimport [options] db_name textfile1 [textfile2 ...]
For each text file named on the command line, mysqlimport strips any extension from the file name and uses the result to determine the name of the table into which to import the file‘s contents. For example, files named patient.txt, patient.text, and patient all would be imported into a table named patient.

mysqlimport supports the following options, which can be specified on the command line or in the [mysqlimport] and [client] groups of an option file. For information about option files used by MySQL programs, see Section 4.2.6, “Using Option Files”.

Table 4.6 mysqlimport Options

Format    Description    Introduced
--columns=column_list    This option takes a comma-separated list of column names as its value     
--compress    Compress all information sent between client and server     
--debug[=debug_options]    Write a debugging log     
--default-character-set=charset_name    Specify default character set     
--defaults-extra-file=file_name    Read option file in addition to usual option files     
--defaults-file=file_name    Read only named option file     
--defaults-group-suffix=str    Option group suffix value    5.0.10
--delete    Empty the table before importing the text file     
--fields-enclosed-by=string    This option has the same meaning as the corresponding clause for LOAD DATA INFILE     
--fields-escaped-by    This option has the same meaning as the corresponding clause for LOAD DATA INFILE     
--fields-optionally-enclosed-by=string    This option has the same meaning as the corresponding clause for LOAD DATA INFILE     
--fields-terminated-by=string    -- This option has the same meaning as the corresponding clause for LOAD DATA INFILE     
--force    Continue even if an SQL error occurs     
--help    Display help message and exit     
--host=host_name    Connect to MySQL server on given host     
--ignore    See the description for the --replace option     
--ignore-lines=#    Ignore the first N lines of the data file     
--lines-terminated-by=string    This option has the same meaning as the corresponding clause for LOAD DATA INFILE     
--local    Read input files locally from the client host     
--lock-tables    Lock all tables for writing before processing any text files     
--low-priority    Use LOW_PRIORITY when loading the table.     
--no-defaults    Read no option files     
--password[=password]    Password to use when connecting to server     
--pipe    On Windows, connect to server using named pipe     
--port=port_num    TCP/IP port number to use for connection     
--print-defaults    Print defaults     
--protocol=type    Connection protocol to use     
--replace    The --replace and --ignore options control handling of input rows that duplicate existing rows on unique key values     
--shared-memory-base-name=name    The name of shared memory to use for shared-memory connections     
--silent    Produce output only when errors occur     
--socket=path    For connections to localhost, the Unix socket file to use     
--ssl    Enable SSL for connection     
--ssl-ca=file_name    Path of file that contains list of trusted SSL CAs     
--ssl-capath=dir_name    Path of directory that contains trusted SSL CA certificates in PEM format     
--ssl-cert=file_name    Path of file that contains X509 certificate in PEM format     
--ssl-cipher=cipher_list    List of permitted ciphers to use for SSL encryption     
--ssl-key=file_name    Path of file that contains X509 key in PEM format     
--ssl-verify-server-cert    Verify server Common Name value in its certificate against host name used when connecting to server    5.0.23
--user=user_name,    MySQL user name to use when connecting to server     
--verbose    Verbose mode     
--version    Display version information and exit     

 --help, -?

Display a help message and exit.

 --character-sets-dir=path

The directory where character sets are installed. See Section 10.5, “Character Set Configuration”.

 --columns=column_list, -c column_list

This option takes a comma-separated list of column names as its value. The order of the column names indicates how to match data file columns with table columns.

 --compress, -C

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

 --debug[=debug_options], -# [debug_options]

Write a debugging log. A typical debug_options string is d:t:o,file_name. The default is d:t:o.

 --default-character-set=charset_name

Use charset_name as the default character set. See Section 10.5, “Character Set Configuration”.

 --defaults-extra-file=file_name

Read this option file after the global option file but (on Unix) before the user option file. As of MySQL 5.0.6, if the file does not exist or is otherwise inaccessible, an error occurs. file_name is the full path name to the file.

 --defaults-file=file_name

Use only the given option file. If the file does not exist or is otherwise inaccessible, an error occurs. file_name is the full path name to the file.

 --defaults-group-suffix=str

Read not only the usual option groups, but also groups with the usual names and a suffix of str. For example, mysqlimport normally reads the [client] and [mysqlimport] groups. If the --defaults-group-suffix=_other option is given, mysqlimport also reads the [client_other] and [mysqlimport_other] groups. This option was added in MySQL 5.0.10.

 --delete, -D

Empty the table before importing the text file.

 --fields-terminated-by=..., --fields-enclosed-by=..., --fields-optionally-enclosed-by=..., --fields-escaped-by=...

These options have the same meaning as the corresponding clauses for LOAD DATA INFILE. See Section 13.2.6, “LOAD DATA INFILE Syntax”.

 --force, -f

Ignore errors. For example, if a table for a text file does not exist, continue processing any remaining files. Without --force, mysqlimport exits if a table does not exist.

 --host=host_name, -h host_name

Import data to the MySQL server on the given host. The default host is localhost.

 --ignore, -i

See the description for the --replace option.

 --ignore-lines=N

Ignore the first N lines of the data file.

 --lines-terminated-by=...

This option has the same meaning as the corresponding clause for LOAD DATA INFILE. For example, to import Windows files that have lines terminated with carriage return/linefeed pairs, use --lines-terminated-by="\r\n". (You might have to double the backslashes, depending on the escaping conventions of your command interpreter.) See Section 13.2.6, “LOAD DATA INFILE Syntax”.

 --local, -L

Read input files locally from the client host.

 --lock-tables, -l

Lock all tables for writing before processing any text files. This ensures that all tables are synchronized on the server.

 --low-priority

Use LOW_PRIORITY when loading the table. This affects only storage engines that use only table-level locking (such as MyISAM, MEMORY, and MERGE).

 --no-defaults

Do not read any option files. If program startup fails due to reading unknown options from an option file, --no-defaults can be used to prevent them from being read.

 --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, mysqlimport prompts for one.

Specifying a password on the command line should be considered insecure. See Section 6.1.2.1, “End-User Guidelines for Password Security”. You can use an option file to avoid giving the password on the command line.

 --pipe, -W

On Windows, connect to the server using a named pipe. This option applies only if the server supports named-pipe connections.

 --port=port_num, -P port_num

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

 --print-defaults

Print the program name and all options that it gets from option files.

 --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”.

 --replace, -r

The --replace and --ignore options control handling of input rows that duplicate existing rows on unique key values. If you specify --replace, new rows replace existing rows that have the same unique key value. If you specify --ignore, input rows that duplicate an existing row on a unique key value are skipped. If you do not specify either option, an error occurs when a duplicate key value is found, and the rest of the text file is ignored.

 --shared-memory-base-name=name

On Windows, the shared-memory name to use, for connections made using shared memory to a local server. The default value is MYSQL. The shared-memory name is case sensitive.

The server must be started with the --shared-memory option to enable shared-memory connections.

 --silent, -s

Silent mode. Produce output only when errors occur.

 --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.

 --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 6.3.6.4, “SSL Command Options”.

 --user=user_name, -u user_name

The MySQL user name 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.

Some options, such as --opt, automatically enable --lock-tables. If you want to override this, use --skip-lock-tables at the end of the option list.

Here is a sample session that demonstrates use of mysqlimport:

shell> mysql -e ‘CREATE TABLE imptest(id INT, n VARCHAR(30))‘ test
shell> ed
a
100     Max Sydow
101     Count Dracula
.
w imptest.txt
32
q
shell> od -c imptest.txt
0000000   1   0   0  \t   M   a   x       S   y   d   o   w  \n   1   0
0000020   1  \t   C   o   u   n   t       D   r   a   c   u   l   a  \n
0000040
shell> mysqlimport --local test imptest.txt
test.imptest: Records: 2  Deleted: 0  Skipped: 0  Warnings: 0
shell> mysql -e ‘SELECT * FROM imptest‘ test
+------+---------------+
| id   | n             |
+------+---------------+
|  100 | Max Sydow     |
|  101 | Count Dracula |
+------+---------------+