This is copy from https://gist.github.com/ibraheem4 Thank you @ibraheem4

Installing Postgres via Brew

Pre-Reqs

Brew Package Manager

In your command-line run the following commands:

  1. brew doctor
  2. brew update

Installing

  1. In your command-line run the command: brew install postgresql
  2. Run the command: ln -sfv /usr/local/opt/postgresql/*.plist ~/Library/LaunchAgents

  3. Create two new aliases to start and stop your postgres server. They could look something like this:

    alias pg_start="launchctl load ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist"
alias pg_stop="launchctl unload ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist"
  4. Run the alias you just created: pg_start. Use this comment to start your database service.
    • alternatively, pg_stop stops your database service.
  5. Run the command: createdb `whoami`
  6. Connect to your postgres with the command: psql
  7. brew reinstall readline - if needed
  8. createuser -s postgres - fixes role "postgres" does not exist

  9. Test with psql command

    $ psql
psql (10.0)
Type "help" for help.

ibraheem=#

Details

What is this ln command I ran in my Terminal?

from the man ln command

The ln utility creates a new directory entry (linked file) which has the same modes as the original file. It is useful for maintaining multiple copies of a

 file in many places at once without using up storage for the ``copies''; instead, a link ``points'' to the original copy.  There are two types of links; hard
 links and symbolic links.  How a link ``points'' to a file is one of the differences between a hard and symbolic link.

What is launchctl?

from the man launchctl command

launchctl interfaces with launchd to manage and inspect daemons, angents and XPC services.

Commands

Create database

createdb <database_name>

createdb mydjangoproject_development

List databases

psql -U postgres -l

Show tables in database

psql -U postgres -d <database_name>

psql -U postgres -d mydjangoproject_development

Drop database

dropdb <database_name>

dropdb mydjangoproject_development

Restart database

dropdb <database_name> && createdb <database_name>

dropdb mydjangoproject_development && createdb mydjangoproject_development