erlang

For example, given record -record(item, { id, time, status}). I want to search the 1000 to 1100 items, ordered by time and status =:= <<"finished">> Any suggestions? It depends on what your queries look like. If you need to order by lots of different columns, then I'd consider using SQL instead of Mnesia. But if you only need the kind of query you described, you should be able to use the ordered_set type of table to handle the ordering and mnesia:select/4 to handle pagination and the constraint. Here's some untested code to give you the gist: % time goes first because it's our primary sort key

Let assume I have two ejabberd server consider X and Y which has the same source and i did ejabberd clustering for those server by using this . Now consider A and B are user and those are connected in X server . Both A and B are in ONLINE state and those are connected via X server . If suppose X server is get shutdown or crashed by some issue. In this sceneraio whether the A and B are get OFFLINE state or A and B are in ONLINE state which is handle by Y server. I don't know whether my thought is right or not. If any one give me the suggestion about it. If you have nodes in different physical

I have created a simple appmod that sends back the same message as it receives. But I get an error message at the command prompt and the WebSocket connection is closed. If I send a message with 3 chars I get this error message: =ERROR REPORT==== 8-Feb-2012::05:09:14 === Error in process <0.59.0> with exit value: {undef,[{mywebsocket,handle_message,[ {text,<<3 bytes>>}],[]},{lists,map,2,[{file,"lists.erl"},{line,1173}]},{yaws_web sockets,loop,4,[{file,"yaws_websockets.erl"},{line,151}]}]} What am I doing wrong? The handle uses text , and it doesn't work if I use binary either. Here is my HTML

fib(N)-> P1 = spawn(fun concFib:conFib/0), P2 = spawn(fun concFib:conFib/0), X=rpc(P1,N-2),Y=rpc(P2,N-1),X+Y. conFib()-> receive {Client,N} -> Client ! regfib(N) end. rpc(Pid,Request)-> case erlang:is_process_alive(Pid) of true -> begin Pid ! {self(),Request}, receive {Pid,Respond} -> Respond end end; false -> io:format("~w process is dead.",[Pid]) end. regfib(N)-> case N<2 of true -> 1; false -> regfib(N,1,1,1) end. regfib(N,N,X,_)-> X ; regfib(N,M,X,Y)-> regfib(N,M+1,X+Y,X). The idea is to divide the fib(N) process into two process one calculates fib(N-2) and the other one calc. fib(N-1)

I'm very new to erlang and I need to code something which inserts rows in a MySQL Database. How can I prevent SQL Injections with Erlang? Is there also something like prepared statements in other Languages or how should I do it? Thanks for your replies. This answer depends on the driver you are using. Erlang ODBC has a function param_query that binds a set of parameters to the query and it might also escape all the SQL special characters. erlang-mysql-driver has prepared statements: %% Register a prepared statement mysql:prepare(update_developer_country, <<"UPDATE developer SET country=? where