· 2 min learn
It is a tutorial for learners about utilizing PostgreSQL. I am going to present you the way to routinely backup and restore the database.
NOTE: In case you are already acquainted with PostgreSQL, however you don’t know a lot about the way to use databases in Vapor, it’s best to learn my different tutorial about Fluent for learners.
A fast intro to PostgreSQL
PostgreSQL is an open supply database, it’s accessible for macOS, Linux and another working programs. You’ll be able to 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
# test service standing
sudo service --status-all
sudo service postgresql standing
# macOS
brew set up postgresql
brew providers begin postgresql
# test service standing
brew providers checklist
You’ll additionally must set a correct password for the postgres consumer, which is the admin consumer by default with godlike permissions. You’ll be able to change the foundation password, you simply must log in as a root & alter the postgres consumer document 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
To any extent further you’ll have the ability to 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 just create as a substitute of working with a shared root consumer. Let me present you the way to create a brand new DB with an related consumer.
# Checklist 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;
# Give up from psql console
q
That’s it, you possibly can 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
# Checklist all tables
dt
# Describe desk construction (can be helpful in a while)
d+
You'll be able to be taught extra about SQL instructions utilizing this pgSQL tutorial website.
WARN: The command beneath can fully 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 improvement, issues can go unsuitable and also you would possibly want a contemporary begin to your DB. Right here’s the way to drop & reinitiate every little 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 mandatory permissions for the required customers. It’s fairly simple however nonetheless harmful. ⚠️
NOTE : You'll be able to 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'll be able to wipe every little 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'll be able to simply restore a database from a backup by getting 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 providers 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 you realize why this occurred to me. 😅
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