PostGIS is spatial database extender for PostgreSQL object-relational database. It adds support for geographic objects allowing location queries to be run in SQL.
When I was setting up a Rails project in my local machine it requires PostGIS setup to run the migration. I have gone through their official sites and many other documents to know about the installation process and found out these processes, to reinstall the PostgreSQL if another version of PostgreSQL is installed previously and installing PostGIS in Mac OS.
Remove previous versions of PostgreSQL
brew uninstall --force postgresql
Delete all Files of Postgres
rm -rf /usr/local/var/postgres
Install Postgres with Homebrew
brew install postgres
Install PostGIS with Homebrew
brew install postgis
Start PostgreSQL server
pg_ctl -D /usr/local/var/postgres start
If terminal shows an error
initdb: directory "/usr/local/var/postgres" exists but is not empty If you want to create a new database system, either remove or empty the directory "/usr/local/var/postgres" or run initdb with an argument other than "/usr/local/var/postgres".
Remove old database file
rm -r /usr/local/var/postgres
Run the initdb command again
Create a new database
This command should show the psql command prompt
psql (10.0) type “help” for help postgis_test=#
Creating extension for PostGIS.
CREATE EXTENSION postgis;
If everything goes well we should see:
postgis_test=#CREATE EXTENSION postgis; CREATE EXTENSION postgis_test=#
Check your PostGIS version
Hopefully this article will save your time .