[erlang-questions] How best to extract value from mnesia query

[lloyd@REDACTED]

Hello,

The result of a mnesia read transaction looks like this: 

   {atomic, Results} where result is either a populated list [value1, ... valueN] or, an empty list [].

If the table is initialized as set, then the returned list will contain at most one value, e.g:

  [value].

If I want to use of the value in a function or to populate another record, I need to extract the value from the list.

I've tried various ways to do this, but they all seem clumsy:

E.g. 

[MyValue]

hd[vlaue]

confirm([]) ->
    not_found;
confirm([Value]) ->
    Value;
confirm(Value) ->
    Value.

Does there happen to be a preferred/conventional/best-practices way to do this?

Many thanks,

LRP