Database date format to DMY (AWS LIghtsail)

To change the date format of your AWS Lightsail PostgreSQL database to ISO DMY, you're on the right track with using the AWS CLI command. However, there are a few things to consider:

1. The command you've used is correct, but make sure you've replaced 'mydatabase' with your actual database name.

2. The parameter 'DateStyle' is case-sensitive, so ensure it's written exactly as shown.

3. The apply method 'immediate' is correct for dynamic parameters like DateStyle.

4. After running the command, you may need to reconnect to your database for the changes to take effect.

If you're still not seeing the desired result, you can try the following steps:

1. First, verify the current parameter value:

   aws lightsail get-relational-database-parameters --relational-database-name your-database-name

2. If the parameter isn't set correctly, run the update command again:

   aws lightsail update-relational-database-parameters --relational-database-name your-database-name --parameters "parameterName=DateStyle,parameterValue='ISO, DMY',applyMethod=immediate"

3. After running the command, wait a few minutes for the changes to propagate.

4. Reconnect to your database and run SELECT NOW(); again to check the format.

If you're still experiencing issues, it's possible that there might be application-level settings overriding the database configuration. In that case, you may need to adjust your application code to format the date as required.

Remember, changing database parameters can have implications for your applications, so always test thoroughly in a non-production environment first.

Sources
Optimize Lightsail database performance with parameter updates - Amazon Lightsail