How does EE know which custom_fields are assigned to which channel?

field groups are created and assigned to sites (exp_field_groups) custom fields are assigned to field groups (exp_channel_fields) channels use a field group (exp_channels)

basically EE attaches custom fields to channels through the field groups table.

@ender thanks!

do you know which particular function (in the API library maybe) connects all that those information into a usable $data array ? (if any)

not sure, I haven’t used the API much… The EE table structure resides pretty thoroughly in “active memory” so to speak, so I usually just query the database for what I need. 😉

Cool. Thanks!