Importing & Exporting PSQL Database Dump using Docker

Before you begin, make sure you have a PostgreSQL Docker image and container ready, along with your SQL dump file. If you don’t already have a PostgreSQL container set up, you’ll need to create one with proper credentials.

$ docker ps

This command lists all active containers. You should see your PostgreSQL container listed. For instance, one named exampledb.

In my case, a friend shared a large dump database with me, and I needed to explore and understand its contents. Since the dataset was quite large, I decided to work with Docker because it offers a faster, persistent, and reusable setup for managing SQL files.

To copy the dump file into your Docker container, use the following command:

$ docker cp path_of_dump_file.sql <container_name>:tmp/<name_stored.sql>

For instance:

$ docker cp ~/Downloads/example_db.sql exampledb:tmp/example_db.sql

If successful, you’ll see a confirmation message like:

Successfully copied 23MB to exampledb:/tmp/example_db.sql

At this point, your SQL file is available inside the container, and you can use it to populate your PostgreSQL database. Once the data is loaded, you can start inspecting, identifying, and debugging your database as needed.

Verify that the file exists inside the container:

$ docker exec -it exampledb ls -lh /tmp

You should see:

$ example_db.sql

If the target database does not exist, create it:

$ docker exec -it exampledb psql -U root -c "CREATE DATABASE example_db;"

Import the Dump into PostgreSQL

$ docker exec -i exampledb psql -U root -d example_db -f /tmp/example_db.sql

The SQL dump was successfully executed, and the data has been imported into the target database.

Export (backup) a PostgreSQL database from a Docker container

If you ever need to export (dump) your PostgreSQL database from Docker back to your local machine, use the following command:

$ docker exec <container_name> pg_dump -U <db_user> <db_name> > file.sql

For instance:

$ docker exec exampledb pg_dump -U root exampledb > example_db_dump.sql

This will create a example_db_dump.sql file on your local system containing the full backup of your database.

Thank you.
Remember to keep learning and exploring new things.