This section describes how to use mysqldump to create SQL-format dump files. For information about reloading such dump files, see Section 6.4.2, “Reloading SQL-Format Backups”.
By default, mysqldump writes information as SQL statements to the standard output. You can save the output in a file:
shell> mysqldump [arguments
] > file_name
To dump all databases, invoke mysqldump with
the --all-databases
option:
shell> mysqldump --all-databases > dump.sql
To dump only specific databases, name them on the command line
and use the --databases
option:
shell> mysqldump --databases db1 db2 db3 > dump.sql
The --databases
option causes
all names on the command line to be treated as database names.
Without this option, mysqldump treats the
first name as a database name and those following as table
names.
With --all-databases
or
--databases
,
mysqldump writes CREATE
DATABASE
and USE
statements prior to the dump output for each database. This
ensures that when the dump file is reloaded, it creates each
database if it does not exist and makes it the default database
so database contents are loaded into the same database from
which they came. If you want to cause the dump file to force a
drop of each database before recreating it, use the
--add-drop-database
option as
well. In this case, mysqldump writes a
DROP DATABASE
statement preceding
each CREATE DATABASE
statement.
To dump a single database, name it on the command line:
shell> mysqldump --databases test > dump.sql
In the single-database case, it is permissible to omit the
--databases
option:
shell> mysqldump test > dump.sql
The difference between the two preceding commands is that
without --databases
, the dump
output contains no CREATE
DATABASE
or USE
statements. This has several implications:
When you reload the dump file, you must specify a default database name so that the server knows which database to reload.
For reloading, you can specify a database name different from the original name, which enables you to reload the data into a different database.
If the database to be reloaded does not exist, you must create it first.
Because the output will contain no
CREATE DATABASE
statement, the--add-drop-database
option has no effect. If you use it, it produces noDROP DATABASE
statement.
To dump only specific tables from a database, name them on the command line following the database name:
shell> mysqldump test t1 t3 t7 > dump.sql