arcgis-knowledge-graphs

ArcGIS 知识图谱

此技能适用于知识图谱、图查询（openCypher）、关联图可视化以及实体关系管理。

导入模式

ESM（npm）

// Knowledge graph service
import * as knowledgeGraphService from "@arcgis/core/rest/knowledgeGraphService.js";

// Layers
import KnowledgeGraphLayer from "@arcgis/core/layers/KnowledgeGraphLayer.js";
import LinkChartLayer from "@arcgis/core/layers/LinkChartLayer.js";

// Views and charts
import WebLinkChart from "@arcgis/core/WebLinkChart.js";
import LinkChartView from "@arcgis/core/views/LinkChartView.js";

// Layout settings
import OrganicLayoutSettings from "@arcgis/core/linkChart/OrganicLayoutSettings.js";
import ChronologicalLayoutSettings from "@arcgis/core/linkChart/ChronologicalLayoutSettings.js";
import LinkChartLayoutSwitcher from "@arcgis/core/linkChart/LinkChartLayoutSwitcher.js";

CDN（动态导入）

const knowledgeGraphService = await $arcgis.import(
  "@arcgis/core/rest/knowledgeGraphService.js",
);
const KnowledgeGraphLayer = await $arcgis.import(
  "@arcgis/core/layers/KnowledgeGraphLayer.js",
);
const WebLinkChart = await $arcgis.import("@arcgis/core/WebLinkChart.js");
const LinkChartView = await $arcgis.import(
  "@arcgis/core/views/LinkChartView.js",
);

知识图谱服务

获取知识图谱

const url =
  "https://your-server/server/rest/services/Hosted/YourKG/KnowledgeGraphServer";
const knowledgeGraph = await knowledgeGraphService.fetchKnowledgeGraph(url);

console.log("Graph name:", knowledgeGraph.name);
console.log("Entity types:", knowledgeGraph.dataModel.entityTypes);
console.log("Relationship types:", knowledgeGraph.dataModel.relationshipTypes);

服务函数

函数	描述
fetchKnowledgeGraph(url)	获取知识图谱元数据和数据模型
executeQuery(kg, params)	执行 openCypher 查询并返回所有结果
executeQueryStreaming(kg, params)	流式传输大型查询结果
executeSearch(kg, params)	对实体进行全文搜索
executeApplyEdits(kg, params)	添加、更新或删除实体和关系

KnowledgeGraphLayer

添加到地图

const kgLayer = new KnowledgeGraphLayer({
  url: "https://your-server/server/rest/services/Hosted/YourKG/KnowledgeGraphServer",
});

await kgLayer.load();
map.add(kgLayer);

配置子图层

const kgLayer = new KnowledgeGraphLayer({
  url: "...",
  inclusionModeDefinition: {
    generateAllSublayers: false,
    namedTypeDefinitions: new Map([
      ["Person", { useAllData: true }],
      ["Location", { useAllData: true }],
    ]),
  },
});

使用 openCypher 查询

基本查询

const result = await knowledgeGraphService.executeQuery(knowledgeGraph, {
  openCypherQuery: "MATCH (n:Person) RETURN n LIMIT 10",
});

console.log("Results:", result.resultRows);

流式查询（大型结果集）

const queryResults = await knowledgeGraphService.executeQueryStreaming(
  knowledgeGraph,
  {
    openCypherQuery: "MATCH (n:Person)-[r]->(m) RETURN n, r, m",
  },
);

const reader = queryResults.resultRowsStream.getReader();

while (true) {
  const { done, value } = await reader.read();
  if (done) break;

  value.forEach((row) => {
    console.log("Row:", row);
  });
}

使用绑定参数进行空间查询

import Polygon from "@arcgis/core/geometry/Polygon.js";

const searchArea = new Polygon({
  rings: [
    [
      [-76, 45],
      [-70, 45],
      [-70, 40],
      [-76, 40],
      [-76, 45],
    ],
  ],
});

const queryResults = await knowledgeGraphService.executeQueryStreaming(
  knowledgeGraph,
  {
    openCypherQuery: `
    MATCH path=(a:User)-[]->(b:Observation)
    WHERE esri.graph.ST_Intersects($geometry, b.shape)
    RETURN path
  `,
    bindParameters: {
      geometry: searchArea,
    },
  },
);

使用过滤条件查询

// Filter by property
const result = await knowledgeGraphService.executeQuery(knowledgeGraph, {
  openCypherQuery: `
    MATCH (p:Person)
    WHERE p.age > 30 AND p.name CONTAINS 'John'
    RETURN p
  `,
});

// Query relationships
const result = await knowledgeGraphService.executeQuery(knowledgeGraph, {
  openCypherQuery: `
    MATCH (p:Person)-[r:WORKS_AT]->(c:Company)
    WHERE c.name = 'Esri'
    RETURN p.name, r.startDate, c.name
  `,
});

常见 openCypher 模式

-- Find all entities of a type
MATCH (p:Person) RETURN p

-- Find relationships
MATCH (a)-[r]->(b) RETURN a, r, b

-- Find path with depth
MATCH path = (a:Person)-[:KNOWS*1..3]->(b:Person)
WHERE a.name = 'John'
RETURN path

-- Aggregate
MATCH (p:Person)-[:WORKS_AT]->(c:Company)
RETURN c.name, COUNT(p) as employeeCount

-- Spatial filter
MATCH (loc:Location)
WHERE esri.graph.ST_Intersects($geometry, loc.shape)
RETURN loc

搜索知识图谱

const searchResults = await knowledgeGraphService.executeSearch(
  knowledgeGraph,
  {
    searchQuery: "John Smith",
    typeCategoryFilter: "entity", // "entity", "relationship", "both"
    typeNames: ["Person", "Employee"],
    returnSearchContext: true,
  },
);

searchResults.results.forEach((result) => {
  console.log("Found:", result.typeName, result.id);
  console.log("Context:", result.searchContext);
});

应用编辑

// Add entity
await knowledgeGraphService.executeApplyEdits(knowledgeGraph, {
  entityAdds: [
    {
      typeName: "Person",
      properties: { name: "Jane Doe", age: 28 },
    },
  ],
});

// Update entity
await knowledgeGraphService.executeApplyEdits(knowledgeGraph, {
  entityUpdates: [
    {
      typeName: "Person",
      properties: { globalId: "{existing-global-id}", age: 29 },
    },
  ],
});

// Delete entity
await knowledgeGraphService.executeApplyEdits(knowledgeGraph, {
  entityDeletes: [
    {
      typeName: "Person",
      ids: ["{global-id-to-delete}"],
    },
  ],
});

// Add relationship
await knowledgeGraphService.executeApplyEdits(knowledgeGraph, {
  relationshipAdds: [
    {
      typeName: "WORKS_AT",
      properties: {
        originGlobalId: "{person-global-id}",
        destinationGlobalId: "{company-global-id}",
        startDate: new Date(),
      },
    },
  ],
});

数据模型

const dataModel = knowledgeGraph.dataModel;

dataModel.entityTypes.forEach((entityType) => {
  console.log("Entity:", entityType.name);
  console.log("Properties:", entityType.properties);
});

dataModel.relationshipTypes.forEach((relType) => {
  console.log("Relationship:", relType.name);
  console.log("Origin:", relType.originEntityTypes);
  console.log("Destination:", relType.destinationEntityTypes);
});

关联图可视化

创建关联图（核心 API）

const linkChartLayer = new LinkChartLayer({
  url: "https://your-server/.../KnowledgeGraphServer",
});

const linkChart = new WebLinkChart({
  layers: [linkChartLayer],
});

const linkChartView = new LinkChartView({
  container: "linkChartDiv",
  map: linkChart,
  highlightOptions: {
    color: [0, 255, 255, 1],
    haloColor: [0, 255, 255, 0.5],
    haloOpacity: 0.8,
  },
});

关联图组件

<arcgis-link-chart>
  <arcgis-legend slot="top-right"></arcgis-legend>
  <arcgis-zoom slot="bottom-right"></arcgis-zoom>
</arcgis-link-chart>

<script type="module">
  const linkChartComponent = document.querySelector("arcgis-link-chart");
  await linkChartComponent.componentOnReady();

  const lcView = linkChartComponent.view;
  const linkChart = lcView.map;

  await linkChart.addRecords([
    { id: "entity1", typeName: "Person" },
    { id: "entity2", typeName: "Company" },
  ]);
</script>

添加和移除记录

// Add records
await linkChart.addRecords([
  { id: "person-1", typeName: "Person" },
  { id: "company-1", typeName: "Company" },
  { id: "rel-1", typeName: "WORKS_AT" },
]);

// Remove records
await linkChart.removeRecords([{ id: "person-1", typeName: "Person" }]);

展开实体

await linkChart.expand({
  ids: ["entity-id"],
  typeName: "Person",
  relationshipTypes: ["KNOWS", "WORKS_AT"],
  direction: "both", // "outgoing", "incoming", "both"
});

导航至实体

linkChartView.goTo([{ id: "person-1", typeName: "Person" }]);

关联图事件

linkChartView.on("click", async (event) => {
  const response = await linkChartView.hitTest(event);
  if (response.results.length > 0) {
    const graphic = response.results[0].graphic;
    console.log("Clicked:", graphic.attributes);
  }
});

根据查询结果更新关联图

async function updateLinkChart(queryResults, linkChart) {
  const reader = queryResults.resultRowsStream.getReader();

  while (true) {
    const { done, value } = await reader.read();
    if (done) break;

    const records = [];
    for (const row of value) {
      for (const record of row[0].path) {
        records.push({
          id: record.id,
          typeName: record.typeName,
        });
      }
    }

    await linkChart.addRecords(records);
  }
}

布局设置

有机布局

const organicLayout = new OrganicLayoutSettings();
linkChart.layoutSettings = organicLayout;

时间顺序布局

const chronoLayout = new ChronologicalLayoutSettings();
linkChart.layoutSettings = chronoLayout;

布局切换器微件

const layoutSwitcher = new LinkChartLayoutSwitcher({
  view: linkChartView,
});

linkChartView.ui.add(layoutSwitcher, "top-right");

布局切换器组件

<arcgis-link-chart>
  <arcgis-link-chart-layout-switcher
    slot="top-right"
  ></arcgis-link-chart-layout-switcher>
</arcgis-link-chart>

WebLinkChart 属性

const webLinkChart = new WebLinkChart({
  portalItem: { id: "LINKCHART_ID" },
  layoutSettings: organicLayout,
});

// Save to portal
await webLinkChart.saveAs({
  title: "My Link Chart",
  snippet: "Visualization of entity relationships",
});

常见问题

1. 需要身份验证：知识图谱服务通常需要身份验证 — 请配置凭据或 OAuth。

2. 大型结果集使用流式传输：对于可能返回大量结果的查询，请使用 executeQueryStreaming；executeQuery 会将所有内容加载到内存中。

3. 几何转换：在空间查询中使用 esri.graph.ST_Intersects 之前，请将几何转换为 WGS84。

4. 区分大小写：openCypher 属性名称区分大小写 — p.Name 和 p.name 是不同的。

5. 查询前先加载：访问子图层或元数据之前，请确保已执行 await kgLayer.load()。

6. 关联图记录：必须将实体和关系都添加为记录，才能显示链接。

参考示例

• knowledgegraph-query — 使用 openCypher 查询知识图谱
• knowledgegraph-knowledgegraphlayer — 使用 KnowledgeGraphLayer
• knowledgegraph-search — 全文搜索
• knowledgegraph-applyedits — 编辑图实体
• knowledgegraph-datamodelediting — 数据模型编辑
• linkchart — 关联图可视化

相关技能

• arcgis-layers — 图层配置和管理
• arcgis-interaction — 命中测试和事件处理
• arcgis-editing — 要素编辑模式