MySQL - Database Export

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MySQL is one of the most popular relational database systems used to store and manage data. It structures data in the form of tables and views so that data handling becomes easier making organizations prefer using MySQL to manage their company's confidential data. Since their data is highly confidential, it becomes necessary to back up the database and restore it whenever necessary. Hence we perform database export.

Exporting a database in MySQL is commonly used for backup purposes or transferring data between servers. You can export entire database or just a portion of it. The simplest way of exporting a database is by using the mysqldump command-line tool.

Exporting Database using mysqldump

The mysqldump command-line tool is used in MySQL to create backups of databases. It can be used to back up an entire database, specific tables, or even specific rows based of a table.

Following is the syntax of mysqldump command to export a database −

$ mysqldump -u username -p database_name > output_file_path

Where,

• username: It is the MySQL username to use when connecting to the database.

• database_name: It is the name of the database to be exported.

• output_file_path: It is the path of the backup file. This is where the backup data will be stored.

• >: This symbol exports the output of the mysqldump command into a file named output_file_path.

Example

First of all, create a database named TUTORIALS using the following query −

Create database TUTORIALS;

Execute the below query to select the current database as TUTORIALS −

USE TUTORIALS;

Let us also create a table named CUSTOMERS in the above-created database −

CREATE TABLE CUSTOMERS (
   ID INT AUTO_INCREMENT,
   NAME VARCHAR(20) NOT NULL,
   AGE INT NOT NULL,
   ADDRESS CHAR (25),
   SALARY DECIMAL (18, 2),
   PRIMARY KEY (ID)
);

The following query inserts 7 records into the CUSTOMERS table −

INSERT INTO CUSTOMERS (ID,NAME,AGE,ADDRESS,SALARY) VALUES 
(1, 'Ramesh', 32, 'Ahmedabad', 2000.00 ),
(2, 'Khilan', 25, 'Delhi', 1500.00 ),
(3, 'Kaushik', 23, 'Kota', 2000.00 ),
(4, 'Chaitali', 25, 'Mumbai', 6500.00 ),
(5, 'Hardik', 27, 'Bhopal', 8500.00 ),
(6, 'Komal', 22, 'Hyderabad', 4500.00 ),
(7, 'Muffy', 24, 'Indore', 10000.00 );

Here, we are using the mysqldump command-line statement to export the TUTORIALS database to the 'datadump.sql' file. Once we execute the below statement, we need to enter our MySQL server password.

$ mysqldump -u root -p TUTORIALS > data-dump.sql

The above command will not produce any visual output. Instead, the 'data-dump.sql' file will be saved in the current working directory of the command prompt or terminal where you executed the command.

Exporting only Specific Tables in Database

We can also export only specific tables in a database using the mysqldump command-line tool. To do so, we use the following syntax −

mysqldump -u username -p database_name table1 table2 ... > output_file.sql

Example

Before exporting, let us create two new tables (STUDENTS and EMPLOYEES) in the above-created TUTORIALS database using the following query −

CREATE TABLE STUDENTS (
   ID INT AUTO_INCREMENT,
   NAME VARCHAR(20) NOT NULL,
   AGE INT NOT NULL,
   ADDRESS CHAR (25),
   FEES DECIMAL (18, 2),
   PRIMARY KEY (ID)
);

Here, we are creating the EMPLOYEES table −

CREATE TABLE EMPLOYEES (
   ID INT AUTO_INCREMENT,
   NAME VARCHAR(20) NOT NULL,
   AGE INT NOT NULL,
   ADDRESS CHAR (25),
   SALARIES DECIMAL (18, 2),
   PRIMARY KEY (ID)
);

Let us fetch the list of tables in the TUTORIALS database using the below query −

Show Tables;

As we can in the output below, we have three tables present in TUTORIALS database −

Tables_in_tutorials
customers
employees
students

Now, let us export two tables named EMPLOYEES and STUDENTS into the 'datadump2.sql' as follows −

$ mysqldump -u root -p TUTORIALS employees students > output_file.sql

Once we executed the above query, it wont display any ouptut. Instead, it exports the data of both the tables into the specified file.

Exporting all Databases in a Host

For instance, you have multiple databases in your host and you want to export all of them in a single query. In such scenario, we can use the "--all-databases" option of mysqldump command.

Example

Following is the query to export all the databases in a host using the --all-databases option −

$ mysqldump -u root -p --all-databases > database_dump.sql

The above command won't show any visible output on the screen. Instead, the 'database_dump.sql' file will be saved in the current working directory of the command prompt or terminal where you ran the command."