Update SQL statements to match PostgreSQL syntax

[admdan]

Everything from .env, config.py, to all the SELECT, INSERT, UPDATE, and DELETE statements need to changed to follow PostgreSQL format. This is a tough one.

[admdan]

I started with the .env file especially for PostgreSQL database connection (host name, username, port number, and password). After that, I changed the config.py to retrieve the connection details from the .env file. Next is the custom db.py where the custom MySQL database connection function is located in. In db.py, I need to use psycopg2 which is the standard PostgreSQL driver instead of the previously used mysql.connector MySQL driver. My __init__.py thankfully did not need to be changed at all.

[admdan]

I started with profile_utils.py because the file contains my helper functions for the profile routes. Also, connecting the PostgreSQL is really hard because there is another node I need to take note of which is Schema. After connecting a new data source (PostgreSQL), I had to go to Database Properties and manually check the clarus schema under clarusdb database. I realised this because every time I edited the MySQL statements to follow PostgreSQL syntax, table and column names will turn red, hinting that Pycharm may not fully connect to PostgreSQL. I also realised that pgAdmin 4 must be opened and connected all the time in order for these variables to not be highlighted in red.

[admdan]

I'm editing profile.py now, will move to assets and other pages next before double-checking the templates accordingly.

[admdan]

I have gone thru all the .py files (11 files altogether including config.py). Now double-checking templates, will try to run the app when I'm done.