After making some schema change in table message in postgresql 13 database, the table is backed up in pgadmin4 in a file named message.sql. The schema change needs to be populated in another database. What I did is to drop the table message in that database. But I have hard time to re-create table message from the backup file messages.sql (not using CREATE table message ....). I use pg_restore to restore data but was not successful for re-creating table schema. Here is command I tried with no luck:
pg_restore --data-only -h localhost -U postgres -W -d dynamo -t messages /home/download/messages.sql
pg_restore --clean -h localhost -U postgres -W -d dynamo -t messages /home/download/messages.sql
I also tried to create an blank table (no column) called messages in the database and repeated above command, again without luck.
Here is how a new table is added to the current database:
backup the current db on the server with pg_dump
create the new database on dev PC with addition of new table
On dev PC, use pgadmin to restore the backup file in step 1 to new database created in step 2.
backup in pgadmin and create a .backup file for db in step 3.
on server, use pg_restore to overwrite the current db with new database backup file created in step 4:
pg_restore --clean -U postgres --dbname=mydb -W -h localhost --verbose /home/download/mydb.backup
open psql terminal to verify the new table
Related
I'm having some issue with my migrations in Heroku. I've tried several things but none seem to work.
I feel like I should just drop the table that's causing the issue, which will delete all the data in production.
If I drop the table, and re-created the table, will I be able to restore all of the data I lost? Because I will backup my database on Heroku before I drop the table.
Thanks!
You should run a backup with
pg_dump -h hostname -p 5432 -U username -F c -t mytable -f dumpfile mydatabase
Then, after you have dropped and re-created the table, you can restore the data with
pg_restore -h hostname -p 5432 -U username -a -d mydatabase dumpfile
However, this will not work if the table structure has changed.
In that case, you might want to use COPY directly to write the data to a file and restore them from there.
Let's for example assume you plan to add another column. Then you could dump with
COPY (SELECT *, NULL FROM mytable) TO '/file/on/dbserver';
After the table was created with the new column, you can
COPY mytable FROM '/file/on/dbserver';
The new column will be filled with the NULL values.
Modify this basic recipe for more fancy requirements.
I am trying to take backup of a schema from a remote Postgresql server (Version:11.5). The below command used to take the backup works:
pg_dump -CFc -h host -U user -d database -n schema -f "/path/data.backup".
Below is the verbose printed, which says the table contents are also dumped:
Besides, I am using Dbeaver tool to restore the backup into the postgresql server (Version:11.5) installed in my local machine. The restore works but the tables are empty.
Is there any other option which needs to be added, to export the data into the backup file ?
I am having some difficulties with restoring the schema of a table. I dumped my Heroku Postgres db and I used pg_restore to restore one table from it into my local db (it has more than 20 tables). It was successfully restored, but I was having issues when I tried to insert new data into the table.
When I opened up my database using psql, I found out that the restored table is available with all the data, but its schema has zero rows. Is there anyway I could import both the table and its schema from the dump? Thank you very much.
This is how I restored the table into my local db:
pg_restore -U postgres --dbname my_db --table=message latest.dump
Edit:
I tried something like this following the official docs, but it just gets blocked and nothing happened. My db is small, no more than a couple of megabytes and the table's schema I am trying to restore has no more than 100 row.
pg_restore -U postgres --dbname mydb --table=message --schema=message_id_seq latest.dump
As a more general answer (I needed to restore a single table from a huge backup), you may want to take a look at this post: https://thequantitative.medium.com/restoring-individual-tables-from-postgresql-pg-dump-using-pg-restore-options-ef3ce2b41ab6
# run the schema-only restore as root
pg_restore -U postgres --schema-only -d new_db /directory/path/db-dump-name.dump
# Restore per table data using something like
pg_restore -U postgres --data-only -d target-db-name -t table_name /directory/path/dump-name.dump
From the Heroku DevCenter here
Heroku Postgres is integrated directly into the Heroku CLI and offers
many helpful commands that simplify common database tasks
You can check here if your environment is correctly configured.
In this way, you can use the Heroku CLI pg:pull command to pull remote data from a Heroku Postgres database to a local database on your machine.
For example:
$ heroku pg:pull HEROKU_POSTGRESQL_MAGENTA mylocaldb --app sushi
I have created a backup of my database using the following commands:
pg_dump -Fc mydatabase > db.dump
I can restore this backup using the pg_restore -C by first creating the database outlined in the backup file and then connecting to it. However, when I try to restore the backup with pg_restore without the -C into a newly created database nothing happens. I run the following command:
pg_restore -d newdatabase
When I attempt to view all columns of newdatabase I get:
ERROR: relation "newdatabase" does not exist
I am essentially doing what the documentation told me:
Any help as to why this is happening or how to restore into a newly created database using pg_restorewould be great.
EDIT:
I just checked if newdatabase exists and it does:
I'm looking to load a database from a backup.gz. The backup is raw sql generated from pg_dump -U postgres app_development -f backup.gz -Z9.
I've tried dropping the db with psql -Upostgres -c "drop database app_development" but I get:
ERROR: database "app_development" is being accessed by other users
DETAIL: There are 3 other sessions using the database.
The same thing happens when I use dropdb.
I don't want to dump to a non-ascii version so I don't think I can use pg_restore.
Also, I'm not sure if it helps, but all this is happening in docker.