Display foreign key values in treegrid in EJ2 TypeScript Treegrid control

27 Apr 20236 minutes to read

Since Tree Grid Databinding concept is of hierarchy relationship, we do not provide in-built support for foreignKey datasource.

To display the foreignKey value at initial rendering, we can use the queryCellInfo event of the Tree Grid and also by using the editType and columns.edit properties of Tree Grid Column, we can render Dropdownlist with external or foreign dataSource.

import { TreeGrid, Edit, Toolbar, ITreeData } from "@syncfusion/ej2-treegrid";
import { foreignKeyData, dropData } from './datasource.ts';
import { DataManager, Query } from "@syncfusion/ej2-data";
import { QueryCellInfoEventArgs, Column, IEditCell } from "@syncfusion/ej2-grids";


let treegrid: TreeGrid = new TreeGrid({
  dataSource: foreignKeyData,
  childMapping: "Children",
  treeColumnIndex: 1,
  height: 269,
  editSettings: {
    allowEditing: true,
    allowAdding: true,
    allowDeleting: true,
    mode: "Cell"
  toolbar: ["Add", "Delete", "Update", "Cancel"],
  queryCellInfo: queryCellInfo,
  columns: [
    { field: "EmpID", headerText: "EmpID", textAlign: "Right", isPrimaryKey: true, width: 70 },
    { field: "Name", headerText: "Employee Name", width: 70 },
    { field: "DOB", headerText: "DOB", textAlign: "Right", width: 70, editType: "datepickeredit",
      format: { skeleton: "yMd", type: "date" } },
    { field: "EmployeeID", headerText: "EmployeeID", textAlign: "Right", editType: "dropdownedit",
      edit: {
        params: {
          dataSource: new DataManager(dropData),
          fields: { text: "EmployeeName", value: "EmployeeID" },
          query: new Query()
      width: 70 },
    { field: "Country", headerText: "Country", width: 90, textAlign: "Right" }
function queryCellInfo(args: QueryCellInfoEventArgs) {
  if ((args.column as Column).field === "EmployeeID") {
    for (var i = 0; i < dropData.length; i++) {
      let data: Object = args.data as Object;
      if (data[(args.column as Column).field] === dropData[i]["EmployeeID"]) {
        (args.cell as HTMLElement).innerText = dropData[i]["EmployeeName"]; // assign the foreignkey field value to the innertext
<!DOCTYPE html>
<html lang="en">

    <title>EJ2 Grid</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript Grid Control" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-grids/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-treegrid/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-buttons/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-popups/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-navigations/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-dropdowns/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-lists/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-inputs/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-calendars/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-splitbuttons/styles/material.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='TreeGrid'></div>        

You can refer to our JavaScript Tree Grid feature tour page for its groundbreaking feature representations. You can also explore our JavaScript Tree Grid example JavaScript Tree Grid example to knows how to present and manipulate data.