How do I echo datase id in base url? CI4?

On your edit page you will need the information of that specific user. User id, or using ids will always be the best option for you.

PHP Code:

<td><a href="<?php echo base_url('/dashboard/fetch_single_data').'/'.$member['id'];?>" class = "btn btn-primary">Edit</a></td>
<td><a href="<?php echo base_url('/YourController/delete_single_user').'/'.$member['id'];?>" class = "btn btn-primary">Delete</a></td> 


Now on your url  for the edit page you will have the user id in one of the url segments.

In your controller:

PHP Code:

$user_id = $this->request->uri->getSegment(2); // or 3 or 4 on which uri segment your id is 


then find the user details according to this id, and send them to the edit_user page as usual.