圖資料庫查詢語言
阿新 • • 發佈:2020-11-17
本文介紹圖資料庫支援的gremlin和Cypher查詢語言。
初始化資料
可使用gremlin api執行
gremlin api
POST http://localhost:8080/gremlin
{"gremlin":"這裡是語句",
"bindings": {},
"language": "gremlin-groovy",
"aliases": {
"graph": "graphname",
"g": "__g_graphname"
}
}
schema
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()
插入資料
// 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)
建立索引
建立索引,使用REST API:
POST http://localhost:8080/graphs/hugegraph/schema/indexlabels
{
"name": "characterAge",
"base_type": "VERTEX_LABEL",
"base_value": "character",
"index_type": "RANGE",
"fields": [
"age"
]
}
查詢
API 說明
支援gremlin
、sparql
和Cypher
api,推薦gremlin和Cypher
cypher api
http://127.0.0.1:8080/graphs/hugegraph/cypher?cypher=
eg:
curl http://127.0.0.1:8080/graphs/hugegraph/cypher?cypher=MATCH%20(n:character)-[:lives]-%3E(location)-[:lives]-(cohabitants)%20where%20n.name=%27pluto%27%20return%20cohabitants.name
gremlin api
POST http://localhost:8080/gremlin
{"gremlin":"這裡是語句",
"bindings": {},
"language": "gremlin-groovy",
"aliases": {
"graph": "graphname",
"g": "__g_graphname"
}
}
sparql api
GET http://127.0.0.1:8080/graphs/hugegraph/sparql?sparql=SELECT%20*%20WHERE%20{%20}
1. 查詢hercules的祖父
g.V().hasLabel('character').has('name','hercules').out('father').out('father')
也可以通過repeat
方式:
g.V().hasLabel('character').has('name','hercules').repeat(__.out('father')).times(2)
cypher
MATCH (n:character)-[:father]->()-[:father]->(grandfather) where n.name='hercules' return grandfather
2. Find the name of hercules's father
g.V().hasLabel('character').has('name','hercules').out('father').value('name')
cypher
MATCH (n:character)-[:father]->(father) where n.name='hercules' return father.name
3. Find the characters with age > 100
g.V().hasLabel('character').has('age',gt(100))
cypher
MATCH (n:character) where n.age > 10 return n
4. Find who are pluto's cohabitants
g.V().hasLabel('character').has('name','pluto').out('lives').in('lives').values('name')
cypher
MATCH (n:character)-[:lives]->(location)-[:lives]-(cohabitants) where n.name='pluto' return cohabitants.name
5. Find pluto can't be his own cohabitant
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')
6. Pluto's Brothers
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')
g.V().hasLabel('character').has('name','hercules').out('father').out('father')
作者:Jadepeng
出處:jqpeng的技術記事本--http://www.cnblogs.com/xiaoqi
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