I can't seem to reset my database while using docker compose. I've tried killing the server, killing just the database, and restarting the machine.
Anyone know the best way to clear out the development database?
Here's what I tried:
docker-compose run web rake db:reset
I am getting this error:
PG::ObjectInUse: ERROR: cannot drop the currently open database
: DROP DATABASE IF EXISTS "postgres"
Couldn't drop database 'postgres'
rake aborted!
I'm using the setup exactly as described by the docker-compose quickstart: https://docs.docker.com/compose/rails/
I have a rails container and a postgres container
You are using the wrong database.
The database postgres is normally not used for user data, but for administrative purposes. For example, if you want to drop a database, you have to be connected to a different database in the PostgreSQL database cluster to issue the SQL statement DROP DATABASE. Normally, the database postgres is used for that purpose, and I have no doubt that Docker does exactly that when it tries to drop a database.
If you really want to drop the database postgres, you'd have to connect to some other database in the cluster. The correct solution, however, is to keep your data in a different database. Then the problem should go away by itself.
Related
I'm running PostgreSQL through a Docker container. I entered the container and used psql to connect to postgres. I created two databases then created a table in test_db. I checked pgAdmin4 and the databases were there but the students table is not showing up in the UI. Not sure why if the databases are showing up?
I see you connected to 'test_db' database in pgadmin, but to 'postgres' database in psql. If you want to see 'students' table from 'test_db' database in psql, you need connect to 'test_db' database firstly instead of 'postgres' database. You can use '\c test_db' command for that in psql, or '-d test_db' command-line parameter when launching psql from command line.
I'm learning some backend stuff, I made a test database locally and filled some data, and then I dump the database to an SQL file with the following command:
pg_dump -U USERNAME DATABASE —no-owner —no-acl -f backup.sql
And finally restore it to Heroku:
heroku pg:psql —app APPNAME < backup.sql
There is only 1 database I’m deploying, however, when I use PGAdmin to connect to it, it shows more than 2000 databases and crashes my computer:
Where are all these databases coming from?
You don't get a dedicated PostgreSQL server with Heroku Postgres. Your databases are co-located with other users' databases on the same server. You'll be able to see the names of other users' databases, but you won't be able to access them.
I'm not sure what "crashes my computer" means, but make sure you are selecting your database when trying to connect.
I created an RDS Postgres instance. I'm new to RDS.
db host:
demodb.xxxuxxvxxxxx.us-east-2.rds.amazonaws.com
db identifier:
demodb
Every tutorial says to connect with this URL:
jdbc:postgresql://demodb.xxxuxxvxxxxx.us-east-2.rds.amazonaws.com:5432/demodb
but every time I do I get this error-
FATAl: database "demodb" does not exist.
I am able to connect using this:
jdbc:postgresql://demodb.xxxuxxvxxxxx.us-east-2.rds.amazonaws.com:5432/postgres
Now, while I was excited to connect after I used SQL workbench to create tables and insert data into those tables, a few hours later all my tables and data were deleted/wiped/dropped. Why would this happen? and How can I prevent it from happening in the future?
FATAl: database "demodb" does not exist.
demodb is db instance identifier. It is NOT the name of your database inside of PostgreSQL.
By default RDS PostgreSQL does not create a database for you. It seems to me that you haven't created an actual database when you setup your RDS PostgreSQL.
To create a database at RDS creation there is an option called Initial database name where you should specify the name of the database you want. Otherwise, no database is created, which is a default behavior:
I am starting to use PostgreSQL and I am confused about the two ways to create a database. When I installed it the first time, the instructions said I have to create a default database with initdb /usr/local/var/postgres When I lookup my databases, I can see that I have a database called postgres. Now I am able to create a database with two other commands whereas the former is the command line script and the latter the SQL command. In the case of a "postgres" called database it would be:
createdb postgres
CREATE DATABASE postgres
Both are setting up a database in my list of databases. When I try to create another database with initdb /usr/local/var/[someDbName] though, it doesn't appear in my list of databases. So what's the difference between initdb and createdb then?
initdb is not used to create a "new database".
As documented in the manual you need it to create a "cluster" or "data directory" which then stores databases created with create database.
Quote from the manual:
Before you can do anything, you must initialize a database storage area on disk. We call this a database cluster. (The SQL standard uses the term catalog cluster.) A database cluster is a collection of databases that is managed by a single instance of a running database server
[...]
In file system terms, a database cluster is a single directory under which all data will be stored. We call this the data directory or data area
In short: initdb creates the necessary directory layout on the harddisk to be able to create and manage databases.
It's a necessary part of the installation process of a Postgres server.
I need to update a dababase from an other database... For this I need to search in existing database if the records exists, if not add... One of the database is locally stored in my computer, and the other one is on heroku... But I don't know how to access heroku database from my computer to create the inserts and to query if I have to insert or not...
Any idea how can I do something like this?
You can connect via any DB tool, e.g. Oracle SQL Developer with Postgres JDBC connector, to a Heroku Postgres DB. The parameters are listed in the GUI of postgres.heroku.com for your instance.