weapp

error_page 500 /500.html;
location /500.html{
    return 500 '{"error": {"status_code": 500,"status": "Internal Server Error"}}';
}

error_page 502 /502.html;
location /502.html{
    return 502 '{"error": {"status_code": 502,"status": "Bad Gateway"}}';
}

Kartones

PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h or --help depending on your psql version):

• -E: will describe the underlaying queries of the \ commands (cool for learning!)
• -l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)