Importing and exporting databases is a common task in software development. You can use data dumps to back up and restore your information. You can also use them to migrate data to a new server or development environment.
In this tutorial, you will work with database dumps in MySQL or MariaDB (the commands are interchangeable). Specifically, you will export a database and then import that database from the dump file.
Step 1 — Exporting a MySQL or MariaDB Database
The mysqldump console utility exports databases to SQL text files. This makes it easier to transfer and move databases. You will need your database’s name and credentials for an account whose privileges allow at least full read-only access to the database.
Use mysqldump to export your database:
mysqldump -u username -p database_name > data-dump.sql
username is the username you can log in to the database with
database_name is the name of the database to export
data-dump.sql is the file in the current directory that stores the output.
The command will produce no visual output, but you can inspect the contents of data-dump.sql to check if it’s a legitimate SQL dump file.
Run the following command:
head -n 5 data-dump.sql
The top of the file should look similar to this, showing a MySQL dump for a database named database_name.
SQL dump fragment -- MySQL dump 10.13 Distrib 5.7.16, for Linux (x86_64) -- -- Host: localhost Database: database_name -- ------------------------------------------------------ -- Server version 5.7.16-0ubuntu0.16.04.1
If any errors occur during the export process, mysqldump will print them to the screen.
Step 2 — Importing a MySQL or MariaDB Database
To import an existing dump file into MySQL or MariaDB, you will have to create a new database. This database will hold the imported data.
First, log in to MySQL as root or another user with sufficient privileges to create new databases:
mysql -u root -p
You’ll see this output confirming the database creation.
Output Query OK, 1 row affected (0.00 sec)
Then exit the MySQL shell by pressing CTRL+D. From the normal command line, you can import the dump file with the following command:
mysql -u username -p new_database < data-dump.sql
username is the username you can log in to the database with
newdatabase is the name of the freshly created database
data-dump.sql is the data dump file to be imported, located in the current directory
If the command runs successfully, it won’t produce any output. If any errors occur during the process, mysql will print them to the terminal instead. To check if the import was successful, log in to the MySQL shell and inspect the data. Selecting the new database with USE new_database and then use SHOW TABLES; or a similar command to look at some of the data.