Web API Basic Operations Sample (Client-side JavaScript)

This sample demonstrates how to perform basic CRUD (create, retrieve, update, and delete) and association and dissociation operations on entity instances using client-side JavaScript.

Note

This sample implements the operations detailed in the Web API Basic Operations Sample and uses the common JavaScript constructs described in Web API Samples (Client-side JavaScript)

Prerequisites

To run this sample, the following is required:

  • Access to Customer Engagement online or on-premises version 8.0 or higher.

  • A user account with privileges to import solutions and perform CRUD operations, typically a system administrator or system customizer security role.

Run this sample

To run this sample, download the solution package here Microsoft CRM Web API Basic Operations Sample (Client-side JavaScript). Download the Microsoft CRM Web API Basic Operations Sample (Client-side JavaScript).zip file and extract the contents. Locate the WebAPIBasicOperations_1_0_0_1_managed.zip solution and import it into your Customer Engagement organization and run the sample. For instructions on how to import the sample solution, see Web API Samples (Client-side JavaScript).

Code sample

This sample includes two web resources:

WebAPIBasicOperations.html

The WebAPIBasicOperations.html web resource provides the context in which the JavaScript code will run.

<html>  
<head>  
    <title>Microsoft CRM Web API Basic Operations Example</title>  
    <meta charset="utf-8" />  
    <meta http-equiv="X-UA-Compatible" content="IE=Edge" />  
    <script src="../ClientGlobalContext.js.aspx" type="text/javascript"></script>  
    <script src="scripts/es6promise.js" type="text/javascript"></script>  
    <script src="scripts/WebAPIBasicOperations.js" type="text/javascript"></script>  

    <style type="text/css">  
        body {  
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;  
        }  

        #preferences {  
            border: inset;  
            padding: 10px 10px;  
        }  

        #output_area {  
            border: inset;  
            background-color: gainsboro;  
            padding: 10px 10px;  
        }  
    </style>  
</head>  
<body>  
    <h1>Microsoft CRM Web API Basic Operations Example</h1>  
    <p>This page demonstrates the CRM Web API's basic operations using JavaScript.</p>  

    <h2>Instructions</h2>  
    <p>  
        Choose your preferences and run the JavaScript code.   
    Use your browser's developer tools to view the output written to the console (e.g.: in [!include[](../../includes/pn-ie-11.md)] or [!include[](../../includes/pn-microsoft-edge.md)],   
    press F12 to load the Developer Tools).  
    </p>  
    <p>  
        Remove sample data (Choose whether you want to delete sample data created during this execution):  
            <br />  
        <input name="removesampledata" type="radio" value="yes" checked />  
        Yes  
            <input name="removesampledata" type="radio" value="no" />  
        No  
    </p>  
    <input type="button" name="start_sample" value="Start Sample" onclick="Sdk.startSample()" />  

</body>  
</html>  

WebAPIBasicOperations.js

The WebAPIBasicOperations.js web resource is the JavaScript library that defines the operations this sample performs.


"use strict";  
var Sdk = window.Sdk || {};  

/**  
 * @function getClientUrl  
 * @description Get the client URL.  
 * @returns {string} The client URL.  
 */  
Sdk.getClientUrl = function () {  
 var context;  
 // GetGlobalContext defined by including reference to   
 // ClientGlobalContext.js.aspx in the HTML page.  
 if (typeof GetGlobalContext != "undefined") {  
  context = GetGlobalContext();  
 } else {  
  if (typeof Xrm != "undefined") {  
   // Xrm.Page.context defined within the Xrm.Page object model for form scripts.  
   context = Xrm.Page.context;  
  } else {  
   throw new Error("Context is not available.");  
  }  
 }  
 return context.getClientUrl();  

};  

/**  
 * An object instantiated to manage detecting the  
 * Web API version in conjunction with the   
 * Sdk.retrieveVersion function  
 */  
Sdk.versionManager = new function () {  
 //Start with base version  
 var _webAPIMajorVersion = 8;  
 var _webAPIMinorVersion = 0;  
 //Use properties to increment version and provide WebAPIPath string used by Sdk.request;  
 Object.defineProperties(this, {  
  "WebAPIMajorVersion": {  
   get: function () {  
    return _webAPIMajorVersion;  
   },  
   set: function (value) {  
    if (typeof value != "number") {  
     throw new Error("Sdk.versionManager.WebAPIMajorVersion property must be a number.")  
    }  
    _webAPIMajorVersion = parseInt(value, 10);  
   }  
  },  
  "WebAPIMinorVersion": {  
   get: function () {  
    return _webAPIMinorVersion;  
   },  
   set: function (value) {  
    if (isNaN(value)) {  
     throw new Error("Sdk.versionManager._webAPIMinorVersion property must be a number.")  
    }  
    _webAPIMinorVersion = parseInt(value, 10);  
   }  
  },  
  "WebAPIPath": {  
   get: function () {  
    return "/api/data/v" + _webAPIMajorVersion + "." + _webAPIMinorVersion;  
   }  
  }  
 })  

}  

//Setting variables specific to this sample within a container so they won't be   
// overwritten by another scripts code  
Sdk.SampleVariables = {  
 entitiesToDelete: [],   // Entity URIs to be deleted later (if user so chooses)  
 deleteData: true,       // Controls whether sample data are deleted at the end of sample run  
 contact1Uri: null,      // e.g.: Peter Cambel  
 contactAltUri: null,    // e.g.: Peter_Alt Cambel  
 account1Uri: null,      // e.g.: Contoso, Ltd  
 account2Uri: null,      // e.g.: Fourth Coffee  
 contact2Uri: null,      // e.g.: Susie Curtis  
 opportunity1Uri: null,  // e.g.: Adventure Works  
 competitor1Uri: null  

}  

/**  
 * @function request  
 * @description Generic helper function to handle basic XMLHttpRequest calls.  
 * @param {string} action - The request action. String is case-sensitive.  
 * @param {string} uri - An absolute or relative URI. Relative URI starts with a "/".  
 * @param {object} data - An object representing an entity. Required for create and update actions.  
 * @param {object} addHeader - An object with header and value properties to add to the request  
 * @returns {Promise} - A Promise that returns either the request object or an error object.  
 */  
Sdk.request = function (action, uri, data, addHeader) {  
 if (!RegExp(action, "g").test("POST PATCH PUT GET DELETE")) { // Expected action verbs.  
  throw new Error("Sdk.request: action parameter must be one of the following: " +  
      "POST, PATCH, PUT, GET, or DELETE.");  
 }  
 if (!typeof uri === "string") {  
  throw new Error("Sdk.request: uri parameter must be a string.");  
 }  
 if ((RegExp(action, "g").test("POST PATCH PUT")) && (!data)) {  
  throw new Error("Sdk.request: data parameter must not be null for operations that create or modify data.");  
 }  
 if (addHeader) {  
  if (typeof addHeader.header != "string" || typeof addHeader.value != "string") {  
   throw new Error("Sdk.request: addHeader parameter must have header and value properties that are strings.");  
  }  
 }  

 // Construct a fully qualified URI if a relative URI is passed in.  
 if (uri.charAt(0) === "/") {  
  //This sample will try to use the latest version of the web API as detected by the   
  // Sdk.retrieveVersion function.  
  uri = Sdk.getClientUrl() + Sdk.versionManager.WebAPIPath + uri;  
 }  

 return new Promise(function (resolve, reject) {  
  var request = new XMLHttpRequest();  
  request.open(action, encodeURI(uri), true);  
  request.setRequestHeader("OData-MaxVersion", "4.0");  
  request.setRequestHeader("OData-Version", "4.0");  
  request.setRequestHeader("Accept", "application/json");  
  request.setRequestHeader("Content-Type", "application/json; charset=utf-8");  
  if (addHeader) {  
   request.setRequestHeader(addHeader.header, addHeader.value);  
  }  
  request.onreadystatechange = function () {  
   if (this.readyState === 4) {  
    request.onreadystatechange = null;  
    switch (this.status) {  
     case 200: // Operation success with content returned in response body.  
     case 201: // Create success.   
     case 204: // Operation success with no content returned in response body.  
      resolve(this);  
      break;  
     default: // All other statuses are unexpected so are treated like errors.  
      var error;  
      try {  
       error = JSON.parse(request.response).error;  
      } catch (e) {  
       error = new Error("Unexpected Error");  
      }  
      reject(error);  
      break;  
    }  
   }  
  };  
  request.send(JSON.stringify(data));  
 });  
};  

/**  
 * @function startSample  
 * @description Runs the sample.   
 * This sample demonstrates basic CRUD+ operations.   
 * Results are sent to the debugger's console window.  
 */  
Sdk.startSample = function () {  
 // Initializing.  
 Sdk.SampleVariables.deleteData = document.getElementsByName("removesampledata")[0].checked;  
 Sdk.SampleVariables.entitiesToDelete = []; // Reset the array.  
 Sdk.SampleVariables.contact1Uri = "";  
 Sdk.SampleVariables.account1Uri = "";  
 Sdk.SampleVariables.account2Uri = "";  
 Sdk.SampleVariables.contact2Uri = "";  
 Sdk.SampleVariables.opportunity1Uri = "";  
 Sdk.SampleVariables.competitor1Uri = "";  

 /**  
  * Behavior of this sample varies by version  
  * So starting by retrieving the version;  
  */  

 Sdk.retrieveVersion()  
 .then(function () {  
  return Sdk.basicCreateAndUpdatesAsync()  
 })  
.then(function () {  
 return Sdk.createWithAssociationAsync()  
})  
.then(function () {  
 return Sdk.createRelatedAsync()  
})  
.then(function () {  
 return Sdk.associateExistingAsync()  
})  
.then(function () {  
 return Sdk.deleteSampleData()  
})  
.catch(function (err) {  
 console.log("ERROR: " + err.message);  
});  

}  

Sdk.retrieveVersion = function () {  
 return new Promise(function (resolve, reject) {  
  Sdk.request("GET", "/RetrieveVersion")  
  .then(function (request) {  
   try {  
    var RetrieveVersionResponse = JSON.parse(request.response);  
    var fullVersion = RetrieveVersionResponse.Version;  
    var versionData = fullVersion.split(".");  
    Sdk.versionManager.WebAPIMajorVersion = parseInt(versionData[0], 10);  
    Sdk.versionManager.WebAPIMinorVersion = parseInt(versionData[1], 10);  
    resolve();  
   } catch (err) {  
    reject(new Error("Error processing version: " + err.message))  
   }  
  })  
  .catch(function (err) {  
   reject(new Error("Error retrieving version: " + err.message))  
  })  
 });  
};  

Sdk.basicCreateAndUpdatesAsync = function () {  
 return new Promise(function (resolve, reject) {  

  // Section 1.  
  //  
  // Create the contact using POST request.   
  // A new entry will be added regardless if a contact with this info already exists in the system or not.  
  console.log("--Section 1 started--");  
  var contact = {};  
  contact.firstname = "Peter";  
  contact.lastname = "Cambel";  

  var entitySetName = "/contacts";  

  Sdk.request("POST", entitySetName, contact)  
 .then(function (request) {  
  // Process response from previous request.  
  Sdk.SampleVariables.contact1Uri = request.getResponseHeader("OData-EntityId");  
  Sdk.SampleVariables.entitiesToDelete.push(Sdk.SampleVariables.contact1Uri); // To delete later  
  console.log("Contact 'Peter Cambel' created with URI: %s", Sdk.SampleVariables.contact1Uri);  

  // Setup for next request.  
  //  
  // Update contact.  
  // Add property values to a specific contact using PATCH request.  
  var contact = {};  
  contact.annualincome = 80000.00;  
  contact.jobtitle = "Junior Developer";  
  return Sdk.request("PATCH", Sdk.SampleVariables.contact1Uri, contact)  
 })  
 .then(function () {  
  // Process response from previous request.  
  console.log("Contact 'Peter Cambel' updated with job title and annual income.");  

  // Setup for next request.  
  //  
  // Retrieve selected properties of a Contact entity using GET request.   
  // NOTE: It is performance best practice to select only the properties you need.  

  // Retrieved contact properties.  
  var properties = [  
   "fullname",  
   "annualincome",  
   "jobtitle",  
   "description"].join();  

  // NOTE: For performance best practices, use $select to limit the properties you want to return  
  // See also: https://msdn.microsoft.com/library/gg334767.aspx#bkmk_requestProperties  
  var query = "?$select=" + properties;  
  return Sdk.request("GET", Sdk.SampleVariables.contact1Uri + query, null);  
 })  
 .then(function (request) {  
  // Process response from previous request.  
  var contact1 = JSON.parse(request.response);  
  var successMsg = "Contact '%s' retrieved:\n"  
      + "\tAnnual income: %s \n"  
      + "\tJob title: %s \n"  
      + "\tDescription: %s";  
  console.log(successMsg,  
      contact1.fullname,      // This property is read-only. Calculated from firstname and lastname.  
      contact1.annualincome,  
      contact1.jobtitle,  
      contact1.description); // Description will be "null" because it has not been set yet.  

  // Setup for next request.  
  //  
  // Update properties.  
  // Set new values for some of the properties and apply the values to the server via PATCH request.  
  // Notice that we are updating the jobtitle and annualincome properties and adding value to the   
  // description property in the same request.  
  var contact = {};  
  contact.jobtitle = "Senior Developer";  
  contact.annualincome = 95000.00;  
  contact.description = "Assignment to-be-determined. ";  
  return Sdk.request("PATCH", Sdk.SampleVariables.contact1Uri, contact);  
 })  
 .then(function () {  
  // Process response from previous request.  
  console.log("Contact 'Peter Cambel' updated:\n"  
                      + "\tJob title: Senior Developer, \n"  
                      + "\tAnnual income: 95000, \n"  
                      + "\tDescription: Assignment to-be-determined.");  

  // Setup for next request.  
  //  
  // Set value for a single property using PUT request.  
  // In this case, we are setting the telephone1 property to "555-0105".  
  var value = { value: "555-0105" };  
  return Sdk.request("PUT", Sdk.SampleVariables.contact1Uri + "/telephone1", value);  
 })  
 .then(function () {  
  // Process response from previous request.  
  console.log("Contact 'Peter Cambel' phone number updated.");  

  // Setup for next request.  
  //  
  // Retrieve single value property.  
  // Get a value of a single property using GET request.  
  // In this case, telephone1 is retrieved. We should get back "555-0105".  
  return Sdk.request("GET", Sdk.SampleVariables.contact1Uri + "/telephone1", null);  
 })  
 .then(function (request) {  
  // Process response from previous request.  
  var phoneNumber = JSON.parse(request.response);  
  console.log("Contact's phone number is: %s", phoneNumber.value);  
 })  
 .then(function () {  
  // Setup for next request.  
  //The following operations require version 8.2 or higher  
  if (Sdk.versionManager.WebAPIMajorVersion > 8 ||  
   (Sdk.versionManager.WebAPIMajorVersion == 8 && Sdk.versionManager.WebAPIMinorVersion >= 2)  
   ) {  
   // Starting with December 2016 update (v8.2), a contact instance can be   
   // created and its properties returned in one operation by using a   
   //'Prefer: return=representation' header.  
   var contactAlt = {};  
   contactAlt.firstname = "Peter_Alt";  
   contactAlt.lastname = "Cambel";  
   contactAlt.jobtitle = "Junior Developer";  
   contactAlt.annualincome = 80000;  
   contactAlt.telephone1 = "555-0110";  
   var properties = [  
    "fullname",  
    "annualincome",  
    "jobtitle"].join();  
   var query = "?$select=" + properties;  
   // Create contact and return its state (in the body).  
   var retRepHeader = { header: "Prefer", value: "return=representation" };  
   Sdk.request("POST", entitySetName + query, contactAlt, retRepHeader)  
  .then(function (request) {  
   var contactA = JSON.parse(request.response);  
   //Because 'OData-EntityId' header not returned in a 201 response, you must instead   
   // construct the URI.  
   Sdk.SampleVariables.contactAltUri = Sdk.getClientUrl() +  
    Sdk.versionManager.WebAPIPath +  
    "/contacts(" +  
    contactA.contactid +  
    ")";  
   Sdk.SampleVariables.entitiesToDelete.push(Sdk.SampleVariables.contactAltUri);  
   var successMsg = "Contact '%s' created:\n"  
       + "\tAnnual income: %s \n"  
       + "\tJob title: %s \n";  
   console.log(successMsg,  
       contactA.fullname,  
       contactA.annualincome,  
       contactA.jobtitle);  
   console.log("Contact URI: %s", Sdk.SampleVariables.contactAltUri);  
  })  
  .then(function () {  
   // Setup for next request.  
   //Similarly, the December 2016 update (v8.2) also enables returning selected properties     
   //after an update operation (PATCH), with the 'Prefer: return=representation' header.  
   var contactAlt = {};  
   contactAlt.jobtitle = "Senior Developer";  
   contactAlt.annualincome = 95000;  
   contactAlt.description = "MS Azure and Dynamics 365 Customer Engagement Specialist";  
   var properties = [  
      "fullname",  
      "annualincome",  
      "jobtitle",  
      "description"].join();  
   var query = "?$select=" + properties;  
   // Update contact and return its state (in the body).  
   var retRepHeader = { header: "Prefer", value: "return=representation" };  
   return Sdk.request("PATCH", Sdk.SampleVariables.contactAltUri + query, contactAlt, retRepHeader);  
  })  
  .then(function (request) {  
   // Process response from previous request.  
   var contactA = JSON.parse(request.response);  
   var successMsg = "Contact '%s' updated:\n"  
       + "\tAnnual income: %s \n"  
       + "\tJob title: %s \n";  
   console.log(successMsg,  
       contactA.fullname,  
       contactA.annualincome,  
       contactA.jobtitle);  
   //End this series of operations:  
   resolve();  
  })  
  .catch(function (err) {  
   reject(err);  
  });  
  }  
  else {  
   resolve();  
  }  
 })  
 .catch(function (err) {  
  reject(err);  
 });  
 });  
};  

Sdk.createWithAssociationAsync = function () {  
 return new Promise(function (resolve, reject) {  
  // Section 2.  
  //  
  // Create a new account entity and associate it with an existing contact using POST request.  
  console.log("\n--Section 2 started--");  
  var account = {};  
  account.name = "Contoso, Ltd.";  
  account.telephone1 = "555-5555";  
  account["primarycontactid@odata.bind"] = Sdk.SampleVariables.contact1Uri; //relative URI ok. E.g.: "/contacts(###)".  

  var entitySetName = "/accounts";  

  Sdk.request("POST", entitySetName, account)  
 .then(function (request) {  
  // Process response from previous request.  
  Sdk.SampleVariables.account1Uri = request.getResponseHeader("OData-EntityId");  
  Sdk.SampleVariables.entitiesToDelete.push(Sdk.SampleVariables.account1Uri);  
  console.log("Account 'Contoso, Ltd.' created.");  

  // Setup for next request.  
  //  
  // Retrieve account's primary contact with selected properties using GET request and 'expand' query.  
  var contactProperties = [  
      "fullname",  
      "jobtitle",  
      "annualincome"  
  ].join();  
  var query = "?$select=name,telephone1&$expand=primarycontactid($select=" + contactProperties + ")";  
  return Sdk.request("GET", Sdk.SampleVariables.account1Uri + query, null);  
 })  
 .then(function (request) {  
  // Process response from previous request.  
  var account1 = JSON.parse(request.response);  
  var successMsg = "Account '%s' has primary contact '%s':  \n"  
                  + "\tJob title:  %s \n"  
                  + "\tAnnual income:  %s ";  
  console.log(successMsg,  
      account1.name,  
      account1.primarycontactid.fullname,  
      account1.primarycontactid.jobtitle,  
      account1.primarycontactid.annualincome);  
  //End this series of operations:  
  resolve();  
 })  
 .catch(function (err) {  
  reject(err);  
 });  
 });  
};  

Sdk.createRelatedAsync = function () {  
 return new Promise(function (resolve, reject) {  

  // Section 3.  
  //  
  // Create related entities (deep insert).  
  // Create the following entities in one operation using deep insert technique:  
  //   account  
  //   |--- contact  
  //        |--- tasks  
  // Then retrieve properties of these entities  
  //  
  // Constructing the entity relationship.  
  console.log("\n--Section 3 started--");  
  var account = {};  
  account.name = "Fourth Coffee";  
  account.primarycontactid = {  
   firstname: "Susie",  
   lastname: "Curtis",  
   jobtitle: "Coffee Master",  
   annualincome: 48000.00,  
   Contact_Tasks: [  
       {  
        subject: "Sign invoice",  
        description: "Invoice #12321",  
        scheduledend: new Date("April 19th, 2016")  
       },  
       {  
        subject: "Setup new display",  
        description: "Theme is - Spring is in the air",  
        scheduledstart: new Date("4/20/2016")  
       },  
       {  
        subject: "Conduct training",  
        description: "Train team on making our new blended coffee",  
        scheduledstart: new Date("6/1/2016")  
       }  
   ]  
  };  

  var entitySetName = "/accounts";  
  Sdk.request("POST", entitySetName, account)  
 .then(function (request) {  
  // Process response from previous request.  
  Sdk.SampleVariables.account2Uri = request.getResponseHeader("OData-EntityId");  
  Sdk.SampleVariables.entitiesToDelete.push(Sdk.SampleVariables.account2Uri);  
  console.log("Account 'Fourth Coffee' created.");  

  // Setup for next request.  
  //  
  // Retrieve account entity info using GET request and 'expand' query.  
  var contactProperties = [  
   "fullname",  
   "jobtitle",  
   "annualincome"].join();  

  // Expand on primarycontactid to select some of contact's properties.  
  // NOTE: With $expand, the CRM server will return values for the selected properties.   
  // The CRM Web API only supports expansions one level deep.  
  // See also: https://msdn.microsoft.com/library/mt607871.aspx#bkmk_expandRelated  
  var query = "?$select=name&$expand=primarycontactid($select=" + contactProperties + ")";  
  return Sdk.request("GET", Sdk.SampleVariables.account2Uri + query, null);  
 })  
 .then(function (request) {  
  // Process response from previous request.  
  var account2 = JSON.parse(request.response);  
  var successMsg = "Account '%s' has primary contact '%s':\n"  
      + "\tJob title:  %s \n"  
      + "\tAnnual income:  %s";  
  console.log(successMsg,  
      account2.name,  
      account2.primarycontactid.fullname,  
      account2.primarycontactid.jobtitle,  
      account2.primarycontactid.annualincome);  

  // Setup for next request.  
  //  
  // Retrieve contact entity and expanding on its tasks using GET request.  
  Sdk.SampleVariables.contact2Uri = Sdk.getClientUrl() + Sdk.versionManager.WebAPIPath + "/contacts(" + account2.primarycontactid.contactid + ")"; //Full URI.  
  Sdk.SampleVariables.entitiesToDelete.push(Sdk.SampleVariables.contact2Uri); // For Susie Curtis  
  var contactProperties = ["fullname", "jobtitle"].join();  
  var contactTaskProperties = ["subject", "description", "scheduledstart", "scheduledend"].join();  

  // Expand on contact_tasks to select some of its properties for each task.  
  var query = "?$select=" + contactProperties +  
      "&$expand=Contact_Tasks($select=" + contactTaskProperties + ")";  
  return Sdk.request("GET", Sdk.SampleVariables.contact2Uri + query, null);  
 })  
 .then(function (request) {  
  // Process response from previous request.  
  var contact2 = JSON.parse(request.response);  
  console.log("Contact '%s' has the following assigned tasks:", contact2.fullname);  

  // construct the output string.  
  var successMsg = "Subject: %s \n"  
  + "\tDescription: %s \n"  
  + "\tStart: %s \n"  
  + "\tEnd: %s \n";  

  for (var i = 0; i < contact2.Contact_Tasks.length; i++) {  
   console.log(successMsg,  
       contact2.Contact_Tasks[i].subject,  
       contact2.Contact_Tasks[i].description,  
       contact2.Contact_Tasks[i].scheduledstart,  
       contact2.Contact_Tasks[i].scheduledend  
   );  
  }  

  //End this series of operations:  
  resolve();  
 })  
 .catch(function (err) {  
  reject(err);  
 });  
 });  
};  

Sdk.associateExistingAsync = function () {  
 return new Promise(function (resolve, reject) {  

  // Section 4  
  //  
  // Entity associations:  
  // Associate to existing entities via the different relationship types:  
  // 1) 1:N relationship - Associate an existing contact to an existing account   
  //      (e.g.: contact - Peter Cambel to account - Fourth Coffee).  
  // 2) N:N relationship - Associate an competitor to opportunity.  

  console.log("\n--Section 4 started--");  
  var contact = {};  
  contact["@odata.id"] = Sdk.SampleVariables.contact1Uri;  

  Sdk.request("POST", Sdk.SampleVariables.account2Uri + "/contact_customer_accounts/$ref", contact)  
 .then(function () {  
  // Process response from previous request.  
  console.log("Contact 'Peter Cambel' associated to account 'Fourth Coffee'.");  

  // Setup for next request.  
  //  
  // Verify that the reference was made as expected.  
  var contactProperties = ["fullname", "jobtitle"].join();  

  // This returns a collection of all associated contacts...in a "value" array.  
  var query = "/contact_customer_accounts?$select=" + contactProperties;  
  return Sdk.request("GET", Sdk.SampleVariables.account2Uri + query, null);  
 })  
 .then(function (request) {  
  // Process response from previous request.  
  var relatedContacts = JSON.parse(request.response).value; //collection is in the "value" array.  
  var successMsg = "\tName: %s, "  
                  + "Job title: %s ";  

  console.log("Contact list for account 'Fourth Coffee': ");  

  for (var i = 0; i < relatedContacts.length; i++) {  
   console.log(successMsg,  
       relatedContacts[i].fullname,  
       relatedContacts[i].jobtitle  
   );  
  }  

  // Setup for next request.  
  //  
  // Disassociate a contact from an account.  
  return Sdk.request("DELETE", Sdk.SampleVariables.account2Uri + "/contact_customer_accounts/$ref?$id=" + Sdk.SampleVariables.contact1Uri, null);  
 })  
 .then(function () {  
  // Process response from previous request.  
  console.log("Contact 'Peter Cambel' disassociated from account 'Fourth Coffee'.");  

  // Setup for next request.  
  //  
  // N:N relationship:  
  // Associate a competitor to an opportunity.  
  var competitor = {};  
  competitor.name = "Adventure Works";  
  competitor.strengths = "Strong promoter of private tours for multi-day outdoor adventures.";  

  var entitySetName = "/competitors";  
  return Sdk.request("POST", entitySetName, competitor);  
 })  
 .then(function (request) {  
  // Process response from previous request.  
  Sdk.SampleVariables.competitor1Uri = request.getResponseHeader("OData-EntityId");  
  Sdk.SampleVariables.entitiesToDelete.push(Sdk.SampleVariables.competitor1Uri);  
  console.log("Competitor 'Adventure Works' created.");  

  // Setup for next request.  
  //   
  // Create a new opportunity...  
  var opportunity = {};  
  opportunity.name = "River rafting adventure";  
  opportunity.description = "Sales team on a river-rafting offsite and team building.";  
  var entitySetName = "/opportunities";  
  return Sdk.request("POST", entitySetName, opportunity);  
 })  
 .then(function (request) {  
  // Process response from previous request.  
  Sdk.SampleVariables.opportunity1Uri = request.getResponseHeader("OData-EntityId");  
  Sdk.SampleVariables.entitiesToDelete.push(Sdk.SampleVariables.opportunity1Uri);  
  console.log("Opportunity 'River rafting adventure' created.");  

  // Setup for next request.  
  //  
  // Associate competitor to opportunity.  
  var competitor = {};  
  competitor["@odata.id"] = Sdk.SampleVariables.competitor1Uri;  
  return Sdk.request("POST", Sdk.SampleVariables.opportunity1Uri + "/opportunitycompetitors_association/$ref", competitor);  
 })  
 .then(function () {  
  // Process response from previous request.  
  console.log("Opportunity 'River rafting adventure' associated with competitor 'Adventure Works'.");  

  // Setup for next request.  
  //  
  // Retrieve competitor entity and expanding on its opportunitycompetitors_association  
  // for all opportunities, using GET request.  
  var opportunityProperties = ["name", "description"].join();  
  var competitorProperties = ["name"].join();  
  var query = "?$select=" + competitorProperties +  
      "&$expand=opportunitycompetitors_association($select=" + opportunityProperties + ")";  
  return Sdk.request("GET", Sdk.SampleVariables.competitor1Uri + query, null);  
 })  
 .then(function (request) {  
  // Process response from previous request.  
  var competitor1 = JSON.parse(request.response);  
  console.log("Competitor '%s' has the following opportunities:", competitor1.name);  
  var successMsg = "\tName: %s, \n"  
                 + "\tDescription: %s";  
  for (var i = 0; i < competitor1.opportunitycompetitors_association.length; i++) {  
   console.log(successMsg,  
       competitor1.opportunitycompetitors_association[i].name,  
       competitor1.opportunitycompetitors_association[i].description  
   );  
  }  

  // Setup for next request.  
  //  
  // Disassociate competitor from opportunity.  
  return Sdk.request("DELETE", Sdk.SampleVariables.opportunity1Uri +  
          "/opportunitycompetitors_association/$ref?$id=" + Sdk.SampleVariables.competitor1Uri, null);  
 })  
 .then(function () {  
  // Process response from previous request.  
  console.log("Opportunity 'River rafting adventure' disassociated with competitor 'Adventure Works'");  
  //End this series of operations:  
  resolve();  
 })  
 .catch(function (err) {  
  reject(err);  
 });  
 });  
};  

Sdk.deleteSampleData = function () {  
 return new Promise(function (resolve, reject) {  

  // House cleaning - deleting sample data  
  // NOTE: If instances have a parent-child relationship, then deleting the parent will,   
  // by default, automatically cascade delete child instances. In this program,   
  // tasks related using the Contact_Tasks relationship have contact as their parent.   
  // Other relationships may behave differently.  
  // See also: https://msdn.microsoft.com/library/gg309412.aspx#BKMK_CascadingBehavior  
  console.log("\n--Section 5 started--");  
  if (Sdk.SampleVariables.deleteData) {  
   for (var i = 0; i < Sdk.SampleVariables.entitiesToDelete.length; i++) {  
    console.log("Deleting entity: " + Sdk.SampleVariables.entitiesToDelete[i]);  
    Sdk.request("DELETE", Sdk.SampleVariables.entitiesToDelete[i], null)  
    .catch(function (err) {  
     reject(new Error("ERROR: Delete failed --Reason: \n\t" + err.message))  
    });  
   }  
   resolve();  
  } else {  
   console.log("Sample data not deleted.");  
   resolve();  
  }  

 });  
};  

See also

Use the Dynamics 365 Customer Engagement Web API
Create an entity using the Web API
Retrieve an entity using the Web API
Update and delete entities using the Web API
Web API Samples
Web API Basic Operations Sample
Web API Basic Operations Sample (C#)
Web API Samples (Client-side JavaScript)
Web API Query Data Sample (Client-side JavaScript)
Web API Conditional Operations Sample (Client-side JavaScript)
Web API Functions and Actions Sample (Client-side JavaScript)