Good morning.

I have a table using a FK in one field (for example, with values A,B,C,D).

If I add a new row choosing value A: is there any way to disable the election of this Value for a another new row?

I mean: adding a new row, the user should only choose between B, C or D, because A has been chosen previously.

Thanks in advance.

Thanks Aleksandar for your answer.

I'm trying to do this with MySQL triggers and procedures, but now I have another question:

I would like to call a procedure just before a table is rendered. I have seen the action "wpdatatables_before_table( $tableId )", but i don't know how to use it. 

In functions.php I have tried:

add_action('wpdatatables_before_table','quitar_ofertas_duplicadas');
function quitar_ofertas_duplicadas() {
 global $wpdb;
    
    $wpdb->query("call ofertasAOfertasTemp;");
    
}

But it doesn't work.

How could I achieve this?

Please, ignore the previous message. I was wrong with the function name...

It works perfectly now :)

In order to do exactly what I need...what action should I use to call the procedure just in the moment a new row has been inserted?

Once again, thanks a lot for your answer.

I tried what you said and it works perfectly. 

add_action('wpdatatables_after_frontent_edit_row','quitar_ofertas_duplicadas');
function quitar_ofertas_duplicadas() {
 global $wpdb;
    
    $wpdb->query("call limpiarOfertasDuplicadas;");
    
}