Multi DB App

A simple flask app to show how to connect to multiple databases within a single application

Note: The Mysql db is used by default for models unless other db is specified using __bind_key__ attribute.

Steps to install dependencies

pip3 install -e .

N.B. 1. You may install it inside venv or system-wide, that's your choice.

Steps to run/use this app:

1. First export/set DATABASE_URL variable in your environment. Example command is given in next step. Don't copy paste given secret key. Create your own.

2. cd into repo. Then, depending on your OS

   1. For Linux, use command

      export DATABASE_URL_POSTGRESQL="postgresql://user:pass@localhost/dbname"
      export DATABASE_URL_MYSQL="mysql://user:pass@localhost:3306/dbname"
      export SECRET_KEY="3faf6054f65d7feb7c76f995fb940808"
      FLASK_APP=multidbapp FLASK_ENV=development flask run
      

   2. For Windows - CMD, use

      set DATABASE_URL_POSTGRESQL="postgresql://user:pass@localhost/dbname"
      set DATABASE_URL_MYSQL="mysql://user:pass@localhost:3306/dbname"
      set SECRET_KEY="3faf6054f65d7feb7c76f995fb940808"
      set FLASK_APP=multidbapp
      set FLASK_ENV=development
      flask run
      

   3. For Windows - PS, use

      $env:DATABASE_URL_POSTGRESQL="postgresql://user:pass@localhost/dbname"
      $env:DATABASE_URL_MYSQL="mysql://user:pass@localhost:3306/dbname"
      $env:SECRET_KEY="3faf6054f65d7feb7c76f995fb940808"
      $env:FLASK_APP=multidbapp
      $env:FLASK_ENV=development
      flask run
      

3. That's all!

If you haven't create tables yet, you can do like this

1. In MySQL DB:

   CREATE TABLE faculty (
   id          smallint(6) NOT NULL AUTO_INCREMENT, 
   name        varchar(50) NOT NULL, 
   isAdmin     boolean, 
   CONSTRAINT fac_pkey_constraint 
       PRIMARY KEY (id)) ENGINE=InnoDB;
   

2. In PostgreSQL DB:

   CREATE TABLE student (
   id                  smallserial NOT NULL,
   name                varchar(50) NOT NULL,
   semester            smallint NOT NULL,
   roll_number         varchar(15) NOT NULL UNIQUE,
   CONSTRAINT stud_pkey_constraint
       PRIMARY KEY (id));
   

3. Then insert some data into the above tables.

Linters used in this project :

1. Python Language Server (pyls) with flake8

2. Stylelint (for html)

Steps to use linters:

1. Install them on your favourite text editor. Vim, Sublime Text, Atom, VS Code and many more are supported.

2. The linters should automatically pick up the configuration file(s) present in the root directory. If not, create an issue, let's find out why?