Importing postgres database in a docker postgres container

Question

I am trying to import an existing database into a postgres docker container. This is how I proceed:

docker run --name pg-docker -e POSTGRES_PASSWORD=***** -d -p 5432:5432 -v BCS/postgres_data postgres

Then

docker exec -it pg-docker bash
psql -U postgres
postgres=# CREATE DATABASE myDB;
psql -U postgres myDB < BCS/mydb.sql

but when i execute the command \dt I have this error Did not find any relations. knowing that my database has already tables. So waht I am doing wrong?

Answer 1

If you are sure that the database installed everything correctly, are you are still not seeing tables, there are 2 things you should double-check:

• When you connect, are you connecting to the right database? If you are using psql in a terminal, the database is specified with the -d switch.

 psql -h <host> -U <user> -d <dbname>

You can also change your database after you connect using the \connect <dbname> command.

• Are you specifying the right schema? \dt will show you tables, but you need to specify a schema first using set schema :

postgres=# \dt

...
<no tables>
...

postgres=# set schema 'my_schema';
postgres=# \dt

...
<my tables>
...

Answer 2

First thing better to go with the approach that is mentioned by @LinPy.

Or better to copy at build time.

Dockerfile

FROM postgres
COPY mydb.sql /docker-entrypoint-initdb.d/

Another option, you do need to script for only DB creation.

FROM postgres
ENV POSTGRES_DB=mydb

The will create DB for you.

POSTGRES_DB

This optional environment variable can be used to define a different name for the default database that is created when the image is first started. If it is not specified, then the value of POSTGRES_USER will be used.

In the above, the Postgres entrypoint will take care of the SQL script.

Second thing, the current issue with database name , Postgress will not treat them in uppercase simply, unless you did sometrick .

Postgresql treats the db name as lowercase, normalising. However, the field in the postgresapi does not replicate this behaviour, thus allowing you to create a database with Capital letters. The fix could be to warn the user that no uppercase letters are allowed in the db aname and to add in a validation rule to the API to stop a user creating such a database.

postgres-api

Change your command to create DB

docker exec -it pg-docker bash
psql -U postgres
postgres=# CREATE DATABASE myDB;

verfiy DB

postgres=# \l
                                 List of databases
   Name    |  Owner   | Encoding |  Collate   |   Ctype    |   Access privileges   
-----------+----------+----------+------------+------------+-----------------------
 mydb      | postgres | UTF8     | en_US.utf8 | en_US.utf8 | 
 postgres  | postgres | UTF8     | en_US.utf8 | en_US.utf8 | 
 template0 | postgres | UTF8     | en_US.utf8 | en_US.utf8 | =c/postgres          +

so the import command will be

psql -U postgres mydb < BCS/mydb.sql

or

psql  -d mydb -U postgres -f ab.sql

Answer 3

You can also have your sql scripts being redirected to the container like that:

Postgres user:

docker exec -i my-postgres-container psql -U postgres < created-db.sql

Regular user:

docker exec -i my-postgres-container psql -d my-db -U my-user < create-schema.sql