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