How to define a graph in GNN?

I am new to graph neural network (GNN). Without knowing a graph in advance, how can we possibly form an adjacency matrix? Assume there are 3 nodes (vertices): A, B, C. There are could be many possible graphs with these 3 nodes such as: (A -- B -- C), (A -- B, A -- C), etc.

many thanks

Topic graph-neural-network deep-learning machine-learning

Category Data Science

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