图数据库查询语言

2020-11-24 15:38:16 浏览数 (1)

本文介绍图数据库支持的gremlin和Cypher查询语言。

初始化数据

可使用gremlin api执行

gremlin api

POST http://localhost:8080/gremlin

代码语言：javascript复制
{"gremlin":"这里是语句",
 "bindings": {},
"language": "gremlin-groovy",
"aliases": {
		"graph": "graphname", 
		"g": "__g_graphname"
	}
}

schema

代码语言：javascript复制
schema = hugegraph.schema()

schema.propertyKey("name").asText().ifNotExist().create()
schema.propertyKey("age").asInt().ifNotExist().create()
schema.propertyKey("time").asInt().ifNotExist().create()
schema.propertyKey("reason").asText().ifNotExist().create()
schema.propertyKey("type").asText().ifNotExist().create()

schema.vertexLabel("character").properties("name", "age", "type").primaryKeys("name").nullableKeys("age").ifNotExist().create()
schema.vertexLabel("location").properties("name").primaryKeys("name").ifNotExist().create()

schema.edgeLabel("father").link("character", "character").ifNotExist().create()
schema.edgeLabel("mother").link("character", "character").ifNotExist().create()
schema.edgeLabel("battled").link("character", "character").properties("time").ifNotExist().create()
schema.edgeLabel("lives").link("character", "location").properties("reason").nullableKeys("reason").ifNotExist().create()
schema.edgeLabel("pet").link("character", "character").ifNotExist().create()
schema.edgeLabel("brother").link("character", "character").ifNotExist().create()

插入数据

代码语言：javascript复制
// add vertices
Vertex saturn = graph.addVertex(T.label, "character", "name", "saturn", "age", 10000, "type", "titan")
Vertex sky = graph.addVertex(T.label, "location", "name", "sky")
Vertex sea = graph.addVertex(T.label, "location", "name", "sea")
Vertex jupiter = graph.addVertex(T.label, "character", "name", "jupiter", "age", 5000, "type", "god")
Vertex neptune = graph.addVertex(T.label, "character", "name", "neptune", "age", 4500, "type", "god")
Vertex hercules = graph.addVertex(T.label, "character", "name", "hercules", "age", 30, "type", "demigod")
Vertex alcmene = graph.addVertex(T.label, "character", "name", "alcmene", "age", 45, "type", "human")
Vertex pluto = graph.addVertex(T.label, "character", "name", "pluto", "age", 4000, "type", "god")
Vertex nemean = graph.addVertex(T.label, "character", "name", "nemean", "type", "monster")
Vertex hydra = graph.addVertex(T.label, "character", "name", "hydra", "type", "monster")
Vertex cerberus = graph.addVertex(T.label, "character", "name", "cerberus", "type", "monster")
Vertex tartarus = graph.addVertex(T.label, "location", "name", "tartarus")

// add edges
jupiter.addEdge("father", saturn)
jupiter.addEdge("lives", sky, "reason", "loves fresh breezes")
jupiter.addEdge("brother", neptune)
jupiter.addEdge("brother", pluto)
neptune.addEdge("lives", sea, "reason", "loves waves")
neptune.addEdge("brother", jupiter)
neptune.addEdge("brother", pluto)
hercules.addEdge("father", jupiter)
hercules.addEdge("mother", alcmene)
hercules.addEdge("battled", nemean, "time", 1)
hercules.addEdge("battled", hydra, "time", 2)
hercules.addEdge("battled", cerberus, "time", 12)
pluto.addEdge("brother", jupiter)
pluto.addEdge("brother", neptune)
pluto.addEdge("lives", tartarus, "reason", "no fear of death")
pluto.addEdge("pet", cerberus)
cerberus.addEdge("lives", tartarus)

创建索引

创建索引，使用REST API：

POST http://localhost:8080/graphs/hugegraph/schema/indexlabels

代码语言：javascript复制
{
	"name": "characterAge",
	"base_type": "VERTEX_LABEL",
	"base_value": "character",
	"index_type": "RANGE",
	"fields": [
		"age"
	]
}

查询

API 说明

支持gremlin、sparql和Cypher api，推荐gremlin和Cypher

cypher api
代码语言：javascript复制
http://127.0.0.1:8080/graphs/hugegraph/cypher?cypher=

eg:

代码语言：javascript复制
curl http://127.0.0.1:8080/graphs/hugegraph/cypher?cypher=MATCH (n:character)-[:lives]->(location)-[:lives]-(cohabitants) where n.name='pluto' return cohabitants.name
gremlin api

POST http://localhost:8080/gremlin

代码语言：javascript复制
{"gremlin":"这里是语句",
 "bindings": {},
"language": "gremlin-groovy",
"aliases": {
		"graph": "graphname", 
		"g": "__g_graphname"
	}
}
sparql api
代码语言：javascript复制
GET http://127.0.0.1:8080/graphs/hugegraph/sparql?sparql=SELECT * WHERE { }

1. 查询hercules的祖父

代码语言：javascript复制
g.V().hasLabel('character').has('name','hercules').out('father').out('father')

也可以通过repeat方式：

代码语言：javascript复制
g.V().hasLabel('character').has('name','hercules').repeat(__.out('father')).times(2)

cypher

代码语言：javascript复制
MATCH (n:character)-[:father]->()-[:father]->(grandfather) where n.name='hercules' return grandfather

2. Find the name of hercules's father

代码语言：javascript复制
g.V().hasLabel('character').has('name','hercules').out('father').value('name')

cypher

代码语言：javascript复制
MATCH (n:character)-[:father]->(father) where n.name='hercules' return father.name

3. Find the characters with age > 100

代码语言：javascript复制
g.V().hasLabel('character').has('age',gt(100))

cypher

代码语言：javascript复制
MATCH (n:character) where n.age > 10 return n

4. Find who are pluto's cohabitants

代码语言：javascript复制
g.V().hasLabel('character').has('name','pluto').out('lives').in('lives').values('name')

cypher

代码语言：javascript复制
MATCH (n:character)-[:lives]->(location)-[:lives]-(cohabitants) where n.name='pluto' return cohabitants.name

5. Find pluto can't be his own cohabitant

代码语言：javascript复制
pluto = g.V().hasLabel('character').has('name', 'pluto')
g.V(pluto).out('lives').in('lives').where(is(neq(pluto)).values('name')

// use 'as'
g.V().hasLabel('character').has('name', 'pluto').as('x').out('lives').in('lives').where(neq('x')).values('name')
代码语言：javascript复制
cypher> MATCH (src:character{name:"pluto"})-[:lives]->()<-[:lives]-(dst:character) RETURN dst.name

6. Pluto's Brothers

代码语言：javascript复制
pluto = g.V().hasLabel('character').has('name', 'pluto').next()
// where do pluto's brothers live?
g.V(pluto).out('brother').out('lives').values('name')

// which brother lives in which place?
g.V(pluto).out('brother').as('god').out('lives').as('place').select('god','place')

// what is the name of the brother and the name of the place?
g.V(pluto).out('brother').as('god').out('lives').as('place').select('god','place').by('name')
代码语言：javascript复制
MATCH (src:Character{name:"pluto"})-[:brother]->(bro:Character)-[:lives]->(dst)
RETURN bro.name, dst.name

网站 http 数据加密服务 api

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