====== postgresql ======

===== Installation =====


  sudo apt update
  sudo apt install postgresql postgresql-contrib postgis postgresql-16-postgis-3
  
  sudo -u postgres psql
  CREATE USER devuser WITH PASSWORD 'devpass';
  CREATE DATABASE myapp OWNER devuser;
  \c myapp
  CREATE EXTENSION postgis;


===== Use =====

  psql -U voyccom_jhagstrand -d voyccom_mai
  (password is in .pgpass)
  
  \h list SQL commands
  \? list psql commands
  \dt list tables in public schema
  
  SELECT * FROM information_schema.tables WHERE table_schema = 'mai';
  
  SELECT column_name, data_type FROM INFORMATION_SCHEMA.COLUMNS WHERE table_name = 'mai';
  
  select table_schema, table_name from information_schema.tables where table_schema not in ('public','pg_catalog','information_schema') group by table_schema, table_name order by table_schema,table_name;