Path Graph representation in memory

[Solomon]

hi guys. i've a problem on ho to represent graphs in memory. i want to
perform pathfinding so that i can get the shortest distance between two
points on a map considering distance and traffic. my data is in an oracle
db,so i want to extract it, represent it in a graph memory in memory and
then employ A* algorithm to do pathfinding. extracting is no big deal, but
i don't know what data structures to use to represent the graph in memory
so that i can be able to associate adjacent nodes and incident paths. The
A* algorithm will be getting data from this structure then using its open
and closed lists to perform its function. i want to use C++ or php. hope
someone out there has done this and can assist me.

regards solomon