Image uploaded can be considered a post child?

No – it’s an attachment for that post. To get the url of an image, locate the image in your Media Library and select View. The image’s url will be in your browser address bar.

Esmi, thanks!

But I need this in the form of a php script.

I have the main Post ID, and I need to get the ID of it’s first attatchment. With this ID, I can select the link directly in the database.

Can you help me?

Have a look at:

https://codex.www.ads-software.com/Function_Reference/get_children

There’s an example in there that uses wp_get_attachment_link().

Enmi, I love you!