· 2 min learn
It is a tutorial for learners about utilizing PostgreSQL. I will present you how one can routinely backup and restore the database.
In case you are already conversant in PostgreSQL, however you don’t know a lot about how one can use databases in Vapor, it is best to learn my different tutorial about Fluent for learners.
A fast intro to PostgreSQL
PostgreSQL is an open supply database, it’s obtainable for macOS, Linux and another working programs. You possibly can set up it through the use of the de-facto package deal supervisor on each platform. 📦
# Linux
sudo apt-get set up postgresql postgresql-contrib
sudo service postgresql begin
# verify service standing
sudo service --status-all
sudo service postgresql standing
# macOS
brew set up postgresql
brew companies begin postgresql
# verify service standing
brew companies listing
You’ll additionally must set a correct password for the postgres
consumer, which is the admin consumer by default with godlike permissions. You possibly can change the foundation password, you simply should log in as a root & alter the postgres consumer report with the brand new cross. 🔑
# Linux
sudo -u postgres psql postgres
# macOS
psql -U postgres
# psql (12.1)
# Sort "assist" for assist.
#
# postgres=#
# ALTER ROLE
alter consumer postgres with password 'mypassword';
# exit
q
Any longer you’ll be capable of entry pgSQL as root on each platforms like this:
psql -h localhost -U postgres
It is suggested to make use of a devoted consumer for each single database that you simply create as an alternative of working with a shared root consumer. Let me present you how one can create a brand new DB with an related consumer.
# Listing of databases
l
# Present present database
choose current_database();
# Create new database
create database mydb;
# Change database
c mydb
# Create consumer
create consumer myuser with encrypted password 'mypassword';
# Grant privileges for consumer on the database
grant all privileges on database mydb to myuser;
# Stop from psql console
q
That’s it, you may handle your database through the use of the newly created myuser
account.
# Log in again to psql console with myuser utilizing mydb
psql -h localhost -U myuser mydb
# Listing all tables
dt
# Describe desk construction (will likely be helpful in a while)
d+
You possibly can be taught extra about SQL instructions utilizing this pgSQL tutorial web site.
The command beneath can utterly wipe your database, be extraordinarily cautious!
Now you're able to mess around with Fluent, however earlier than we begin I’d like to point out you some extra suggestions & methods. Throughout growth, issues can go improper and also you may want a recent begin on your DB. Right here’s how one can drop & reinitiate every thing. 😱
# Reset database
c mydb
drop schema public cascade;
create schema public;
grant all on schema public to postgres;
grant all on schema public to myuser;
grant all on schema public to public;
The snippet above will delete the public schema, subsequent it’ll recreate it and add all the required permissions for the required customers. It’s fairly easy however nonetheless harmful. ⚠️
NOTE : You possibly can execute SQL scripts straight from the terminal through the use of the next command: psql -h localhost -U myuser mydb -c "choose * from mytable;"
You possibly can wipe every thing from the command line utilizing this “one-liner”:
# Run psql command from the command line
psql -h localhost -U postgres mydb
-c "drop schema public cascade;
create schema public;
grant all on schema public to postgres;
grant all on schema public to myuser;
grant all on schema public to public;"
I desire to have every day backups from all my databases, this little shell script can do the job.
#!/bin/bash
# Backup database
BACKUP_DIR=/Customers/tib/backups
FILE_SUFFIX=_pg_backup.sql
OUTPUT_FILE=${BACKUP_DIR}/`date +"%Y_percentm_percentd__percentH_percentM"`${FILE_SUFFIX}
PGPASSWORD="mypass" pg_dump -U myuser -h localhost mydb -F p -f ${OUTPUT_FILE}
gzip $OUTPUT_FILE
# Take away outdated backups
DAYS_TO_KEEP=30
discover $BACKUP_DIR -maxdepth 1 -mtime +$DAYS_TO_KEEP -name "*${FILE_SUFFIX}.gz" -exec rm -rf '{}' ';'
You possibly can simply restore a database from a backup by coming into the next traces to the terminal:
# Restore database
gunzip -k file.gz
psql -U myuser -d mydb -1 -f mybackup.sql
Typically after I restarted my mac it occurred to me that the PostgreSQL stopped working. I needed to run the snippet beneath to repair the problem. The primary line stops the service, the second initialize a brand new database, and the third will begin the service once more. Alternatively, you can begin the database once more with the brew companies begin postgresql
command.
pg_ctl -D /usr/native/var/postgres cease -s -m quick
initdb /usr/native/var/postgres
pg_ctl -D /usr/native/var/postgres -l /usr/native/var/postgres/server.log begin
I’m not a DevOps guru, be happy to tweet me if why this occurred to me. 😅
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