How to use the command 'createdb' (with examples)

The ‘createdb’ command is used to create a PostgreSQL database. It allows users to create a new database with specific ownership, template, and description. This command is useful when setting up a new database for an application or when creating a database for a specific user.

Use case 1: Create a database owned by the current user

Code:

createdb database_name

Motivation: This use case is helpful when you want to create a database owned by the currently logged in user. When you create a database using this command, you will have full control and ownership over it.

Explanation:

• createdb: The command to create a new database.
• database_name: The name of the database you want to create.

Example output:

CREATE DATABASE database_name;

Use case 2: Create a database owned by a specific user with a description

Code:

createdb --owner=username database_name 'description'

Motivation: This use case is useful when you want to create a database for a specific user and provide a description for the database. Specifying the owner ensures that the specified user has full control and ownership over the database, and the description can provide additional information about the purpose of the database.

Explanation:

• --owner=username: Specifies the user who will own the database.
• database_name: The name of the database you want to create.
• 'description': A description for the database (optional).

Example output:

CREATE DATABASE database_name WITH OWNER username TEMPLATE template0 ENCODING 'UTF8';

COMMENT ON DATABASE database_name IS 'description';

Use case 3: Create a database from a template

Code:

createdb --template=template_name database_name

Motivation: This use case is helpful when you want to create a new database based on an existing template. Templates can be pre-configured with certain settings or schemas, allowing you to create new databases that inherit those characteristics.

Explanation:

• --template=template_name: Specifies the template to use when creating the database.
• database_name: The name of the database you want to create.

Example output:

CREATE DATABASE database_name TEMPLATE template_name;

Conclusion:

The ‘createdb’ command is a powerful tool for creating PostgreSQL databases. It allows you to create databases owned by specific users, provides the ability to add descriptions to databases, and offers the option to create databases based on existing templates. By using the various options and arguments provided by the command, you can easily create and configure databases to suit your needs.