arangodb的graph之一

A Graph consists of vertices and edges.
graph分为named graphs，anonymous graphs
AQL Graph Operations 包含两种：
AQL Traversals 遍历
AQL Shortest Path 最短路径
vertex，vertice，document是近义词
edge，relation是近义词
aql Traversals 语法：
[WITH vertexCollection1[, vertexCollection2[, …vertexCollectionN]]]
FOR vertex[, edge[, path]]
IN [min[…max]]
OUTBOUND|INBOUND|ANY startVertex
GRAPH graphName
[OPTIONS options]
或者：
[WITH vertexCollection1[, vertexCollection2[, …vertexCollectionN]]]
FOR vertex[, edge[, path]]
IN [min[…max]]
OUTBOUND|INBOUND|ANY startVertex
edgeCollection1, …, edgeCollectionN
[OPTIONS options]