[erlang-questions] array search problem

[Roelof Wobben]

Hello,

Im still struggeling to make the database exercise working.

I have to implement a read method which outputs as this :

5> db:read(francesco, Db2).
{ok,london}
6>  Db3 = db:write(joern, stockholm, Db2).
[{joern,stockholm},{lelle,stockholm},{francesco,london}]
7>  db:read(ola, Db3).
{error,instance}

To achieve this do I need to use a try catch or can  I achieve this with 
only pattern matching.

Roelof