Error establishing a database connection (after changing domain)

Is the new domain hosted at the same host?
Backing up only the WP files – means you saved your customized theme(s), if any.
I hope you have a backup of your database, too, since all your content (posts, pages, comments, settings etc.) have been stored in the database, not in the files.

Hopefully it is not too late to take a look at the guides in the Codex: Moving_WordPress

Moshu, yes the new domain is with the same host.
They have not deleted the files from the old domain yet.

I am not quite sure what you mean by stored in the files since I have downloaded every thing from the old domain and I uploaded it to the new domain which currently hosted in different server. I thought it should carry the same.

Apparently when you view meekness.net and vickyay.com has the same files but only when I tried logging into WordPress and changed the Blog address to https://vickyay.com/blog.
It appeared Sorry, you need to enable sending referrers for this feature to work.

And later it says

“Can’t select database”

We were able to connect to the database server (which means your username and password is okay) but not able to select the vickyay_wordpress database.

I am not quite sure what I did wrong.

Usually that error means you have the DB username or password wrong (or both).

I said quite the opposite: NOTHING is stored in files, but in the database. Downloading the files… will not save your old blog. The content is NOT in files. It is in the database.

So, let’s get back to the basics: was the old database transferred to the new location? Did you read the tutorial I linked to? (I am afraid you didn’t – it’s a long article:)

?? I have read it and backup the database. Thank you. Didn’t know it is such a long process.

However, when I tried to logon it is still the error of “Can’t select the database”

How should I proceed now?

Backup is fine. Glad you managed it. Now the next step is to restore it in the new location. Did you do that, too?
And is the database name, user, pw etc. the same as on the old domain? Remember, you have to put those 4 pieces of info in your wp-config.php file.

Does that mean import *.sql to the new domain.
Yes, I did that.

Database name, user, password are all the same as old domain.
I compared the old wp-config and update exact the same details to new wp-config.php file.

But it does not work.

Check and recheck the DB name: the error message says:
not able to select the vickyay_wordpress database

Moshu ?? I did it!

Yes, I realised I have not added the user into the database. Oversighted. ??

Thank you so much for helping me, moving forward I will remember to save the DATABASE and NOT the file.

Cheers!

Hi Moshu, I seek your assistance again to explain why did the blog sometimes recognise it as the old domain, and sometimes the new domain? I reckon they are now in a seperate database in each different server individually, but how come it confuses each other?

When I change the details in OPTION> Blog address to the new domain/blog and it says “Sorry, you need to enable sending referrers for this feature to work.” Which I did change the value to 2 (by default) but it is still the same case.

Could you help?

Could anyone help? the problem is still unsolved.