How get data from Mnesia and print by Yaws

Question

Please, help find info about building on Erlang application what can print various info from Mnesia by Yaws

Best regards, and many thanks for help.

score 2 · Answer 1 · answered May 20 '14 at 06:10

Now i solve by this code:

Mnesia query:

lookup_artists() ->
    Fun = fun() ->
    %       mnesia:read({sensors,Id})
            Query = #artists{ artist_id = '$1', artist = '$2', _ = '_'},
            mnesia:select(artists, [{Query, [], ['$$']}])
    end,
    mnesia:transaction(Fun).

And YAWS file:

<html>
<h1>Test query</h1>
<erl>
out(A) ->
AddTd = fun(Val) ->
%        {td, [], integer_to_list(Val)}
io:format("~n ~p:~p GET Request Response ~p ~n", [?MODULE, ?LINE, Val]),

case is_integer(Val) of
    true  -> {td, [], integer_to_list(Val)};
    false -> {td, [], Val}
end
        end,
AddTr = fun(Val) ->
                {tr, [], lists:map(AddTd, Val)}
        end,
{atomic, Accounts} = wmb2:lookup_artists(),
{ehtml, [{table, [],
         lists:append([[{tr, [], [{td, [], "ID"},
                                  {td, [], "Artist"}]}], 
                       lists:map(AddTr, Accounts)])},
        {p, [], {b, [], f("Total: ~w", [length(Accounts)])}}]}.
 </erl>
 <p><a href="index.yaws">Index</a></p>
 </html>

Don't know ... it's good code or not, but working fine :)

score 0 · Answer 2 · answered May 19 '14 at 05:36

Yaws is a webserver, Mnesia a DBMS. Now, you basically need to learn Erlang first, then, learn how to read, write, update and delete from a mnesia Database. Yaws and mnesia can run within the same erlang VM, after-all, mnesia comes packaged within every standard erlang release.

When you install yaws, under usual circumstances, it will use the installed Erlang VM to run on, and in that same instance, you are able to start mnesia and do what you want. Your question is rather broad/vague, but, i guess i will just send you to an erlang book.

Now i solve my problem. Solution in previous answer. – Black_13 May 21 '14 at 09:51 — Black_13, May 21 '14 at 09:51

How get data from Mnesia and print by Yaws

2 Answers2