在分析了如何编译启动cayley图数据库,并使用它自带的Gizmo工具来进行查询后,我们来看看使用客户端如何进行查询。
首先使用官方的github.com/cayleygraph/go-client,但是它声明的go.mod文件有问题,修改调整后,使用如下:
package mainimport ( "context" "fmt" //client "github.com/cayleygraph/go-client" "learn/test/cayley/go-client/client")func main() { c := client.NewAPIClient(client.NewConfiguration()) result, _, _ := c.QueriesApi.Query(context.TODO(), "gizmo", "g.V().getLimit(10)") fmt.Printf("%v", result.Result)}
运行后,我们可以看到结果
% go run ./test/cayley/exp1/main.go&[map[id:_:100000] map[id:</film/performance/actor>] map[id:</en/larry_fine_1902>] map[id:_:100001] map[id:</en/samuel_howard>] map[id:_:100002] map[id:</en/joe_palma>] map[id:_:100003] map[id:</en/symona_boniface>] map[id:_:100004]]
图数据是由一条条四元组构成,其中第一个叫subject(主语),第二个叫predicate(谓语),第三个叫object(宾语),第四个叫Label(可选),以.结尾。subject和object会转换成有向图的顶点,predicate就是边。label的用法是,你可以在一个数据库里,存多个图,用label来区分不同的图。我们可以使用四元祖操作数据库
package mainimport ( "fmt" "log" "github.com/cayleygraph/cayley" "github.com/cayleygraph/quad")func main() { // Create a brand new graph store, err := cayley.NewMemoryGraph() if err != nil { log.Fatalln(err) } store.AddQuad(quad.Make("phrase of the day", "is of course", "Hello World!", nil)) // Now we create the path, to get to our data p := cayley.StartPath(store, quad.String("phrase of the day")).Out(quad.String("is of course")) // Now we iterate over results. Arguments: // 1. Optional context used for cancellation. // 2. Flag to optimize query before execution. // 3. Quad store, but we can omit it because we have already built path with it. err = p.Iterate(nil).EachValue(nil, func(value quad.Value) { nativeValue := quad.NativeOf(value) // this converts RDF values to normal Go types fmt.Println(nativeValue) }) if err != nil { log.Fatalln(err) }}
运行结果如下
% go run ./test/cayley/exp2/main.goHello World!
当然,我们也可以把后端存储转换为boltdb
package mainimport ( _ "github.com/cayleygraph/cayley/graph/kv/bolt" "github.com/cayleygraph/cayley" "github.com/cayleygraph/cayley/graph")func open() { path := "./" // Initialize the database graph.InitQuadStore("bolt", path, nil) // Open and use the database cayley.NewGraph("bolt", path, nil)}func main() { open()}
以上就是通过golang客户端来操作cayley图数据库的一些常见方法。
版权声明:内容来源于互联网和用户投稿 如有侵权请联系删除