Not able to connect to Amazon RDS from EC2 Django Instance - mysql

Question

I was deploying my Django Project on AWS (this is my first time doing this) after a lot of first time learning i got stuck at an error :
django.db.utils.OperationalError: (2005, "Unknown MySQL server host '****.*****.us-east-2.rds.amazonaws.com' (0)")
When i tried migrating my Django Project.I tried multiple solutions but none worked. I tried command mysql -u username -p password -h ****.********.us-east-2.rds.amazonaws.com but this also returned and error.
ERROR 2005 (HY000): Unknown MySQL server host '*****.*********.us-east-2.rds.amazonaws.com' (2)
UPDATE 2: I Tried using command on AWS Documentation mysql -h mysql–instance1.123456789012.us-east-1.rds.amazonaws.com -P 3306 -u mymasteruser -p which have -h before using -u and -p and an input for Port this changed the error which seems like now the connection is not not able to reach the server which seems a reasonable and a better error than before.
ERROR 2003 (HY000): Can't connect to MySQL server on '******.******l2la.us-east-2.rds.amazonaws.com' (10060)
I read in question this about this,they are talking about binding the instance to an IP.How can i do that if that could be the problem?
UPDATE1:
Screenshots:
FIRST RDS INFORMATION
EC2 instance Information
SGs information
If you require any log or information please feel free to ask in the comments.
Thanks

Answer 1

The security group of Database should hold a Value in Inbound Rules :
This Rule should allow connection from your EC2 Instance.Either set the IP Address or set the SG of EC2 Instance.
You can use the Private IP of your instance rather than the Public IP also.
(Not sure about Security Concerns or Advantages.)
Update After a Year: Well you should use private IP and not the same security
group.DB should only be accessible to the EC2 and not to public.