sqlg rdbms 上实现的Apache TinkerPop
sqlg 可以让关系型数据库支持Apache TinkerPop，当前支持的数据库有postgresql，hsqldb，h2，mariadb，mysql，mssqlserver
以下是一个简单的使用
环境准备
- postgresql
version: "3"
services:
postgres:
image: postgres:9.6.11
ports:
- "5432:5432"
environment:
- "POSTGRES_PASSWORD:dalong"
代码
简单测试，了解下实现处理
- maven pom文件
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.dalong</groupId>
<artifactId>tinkerpop-postgresql</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<encoding>UTF-8</encoding>
<java.version>1.8</java.version>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>org.umlg</groupId>
<artifactId>sqlg-postgres</artifactId>
<version>2.0.0</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.8</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
- 代码结构
├── README.md
├── docker-compose.yaml
├── pom.xml
├── src
│ ├── main
│ │ ├── java
│ │ │ └── com
│ │ │ └── dalong
│ │ │ └── Application.java
│ │ └── resources
│ │ └── datasource.properties
│ └── test
│ └── java
│ └── InsertTest.java
- 测试代码
InsertTest.java
import org.apache.tinkerpop.gremlin.structure.Graph;
import org.apache.tinkerpop.gremlin.structure.T;
import org.apache.tinkerpop.gremlin.structure.Vertex;
import org.junit.Before;
import org.junit.Test;
import org.umlg.sqlg.structure.SqlgGraph;
import java.time.LocalDate;
import java.util.List;
import static junit.framework.Assert.assertEquals;
public class InsertTest {
Graph sqlgGraph = null;
public InsertTest(){
sqlgGraph = SqlgGraph.open("datasource.properties");
}
@Test
public void useAsPerNormal() {
Vertex person = this.sqlgGraph.addVertex(T.label, "Person", "name", "John");
Vertex address = this.sqlgGraph.addVertex(T.label, "Address", "street", "13th");
person.addEdge("livesAt", address, "since", LocalDate.of(2010, 1, 21));
this.sqlgGraph.tx().commit();
List<Vertex> addresses = this.sqlgGraph.traversal().V().hasLabel("Person").out("livesAt").toList();
assertEquals(3, addresses.size());
}
@Test
public void testElementsInSchema() {
Vertex john = this.sqlgGraph.addVertex(T.label, "Manager", "name", "john");
Vertex palace1 = this.sqlgGraph.addVertex(T.label, "continent.House", "name", "palace1");
Vertex corrola = this.sqlgGraph.addVertex(T.label, "fleet.Car", "model", "corrola");
palace1.addEdge("managedBy", john);
corrola.addEdge("owner", john);
this.sqlgGraph.tx().commit();
assertEquals(1, this.sqlgGraph.traversal().V().hasLabel("Manager").count().next().intValue());
assertEquals(0, this.sqlgGraph.traversal().V().hasLabel("House").count().next().intValue());
assertEquals(1, this.sqlgGraph.traversal().V().hasLabel("continent.House").count().next().intValue());
assertEquals(0, this.sqlgGraph.traversal().V().hasLabel("Car").count().next().intValue());
assertEquals(1, this.sqlgGraph.traversal().V().hasLabel("fleet.Car").count().next().intValue());
assertEquals(1, this.sqlgGraph.traversal().E().hasLabel("managedBy").count().next().intValue());
assertEquals(1, this.sqlgGraph.traversal().E().hasLabel("owner").count().next().intValue());
}
}
- 启动&&运行
使用junt 运行测试 - 效果
- sql 生成处理
官方包含了关于sql生成的处理过程
如下以下处理：
@Test
public void showVertexStep() {
Vertex a1 = this.sqlgGraph.addVertex(T.label, "A", "name", "a1");
Vertex b1 = this.sqlgGraph.addVertex(T.label, "B", "name", "b1");
Vertex b2 = this.sqlgGraph.addVertex(T.label, "B", "name", "b2");
Vertex c1 = this.sqlgGraph.addVertex(T.label, "C", "name", "c1");
Vertex c2 = this.sqlgGraph.addVertex(T.label, "C", "name", "c2");
a1.addEdge("ab", b1);
a1.addEdge("ab", b2);
b1.addEdge("bc", c1);
b2.addEdge("bc", c2);
this.sqlgGraph.tx().commit();
GraphTraversal<Vertex, Vertex> traversal = this.sqlgGraph.traversal().V()
.hasLabel("A")
.out()
.out();
System.out.println(traversal);
traversal.hasNext();
System.out.println(traversal);
List<Vertex> c = traversal.toList();
assertEquals(2, c.size());
生成的sql
SELECT
"public"."V_C"."ID" AS "alias1",
"public"."V_C"."name" AS "alias2"
FROM
"public"."V_A" INNER JOIN
"public"."E_ab" ON "public"."V_A"."ID" = "public"."E_ab"."public.A__O" INNER JOIN
"public"."V_B" ON "public"."E_ab"."public.B__I" = "public"."V_B"."ID" INNER JOIN
"public"."E_bc" ON "public"."V_B"."ID" = "public"."E_bc"."public.B__O" INNER JOIN
"public"."V_C" ON "public"."E_bc"."public.C__I" = "public"."V_C"."ID"
以上只是部分，实际上sqlg 也做了很多的优化处理
说明
facebook 开源的ent 也是一个类似的，但是ent 从性能以及使用上就很简单了，ent支持代码生成（主要基于模版）
ent 对于图遍历的各种模型的支持还是比较全的，只是当前支持的数据库比较少，mysql，sqlite 以及gremlin，计划
线路有支持postgresql，同时代码中也包含了，部分关于pg 的处理。
参考资料
https://github.com/apache/tinkerpop/
http://sqlg.org/docs/2.0.0-SNAPSHOT/#_introduction
https://github.com/facebookincubator/ent
