Web API Basic Operations Sample (Client-side JavaScript)

Note

Unsure about entity vs. table? See Developers: Understand terminology in Microsoft Dataverse.

This sample demonstrates how to perform basic CRUD (create, retrieve, update, and delete) and association and dissociation operations on tables rows (entity records) 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 Microsoft Dataverse environment.
  • 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 from here and extract the contents. Locate the WebAPIBasicOperations_1_0_0_1_managed.zip solution and import it into your Dataverse environment 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 IE 11
      or Microsoft Edge, 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 = 80000.0;
        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 = 95000.0;
        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 = "?$select=" + properties;
          // Create contact and return its state (in the body).
          var retRepHeader = {
            header: "Prefer",
            value: "return=representation",
          };
          Sdk.request("POST", entitySetName + query, contactAlt, retRepHeader)
            .then(function (request) {
              var contactA = JSON.parse(request.response);
              //Because 'OData-EntityId' header not returned in a 201 response, you must instead
              // construct the URI.
              Sdk.SampleVariables.contactAltUri =
                Sdk.getClientUrl() +
                Sdk.versionManager.WebAPIPath +
                "/contacts(" +
                contactA.contactid +
                ")";
              Sdk.SampleVariables.entitiesToDelete.push(
                Sdk.SampleVariables.contactAltUri
              );
              var successMsg =
                "Contact '%s' created:\n" +
                "\tAnnual income: %s \n" +
                "\tJob title: %s \n";
              console.log(
                successMsg,
                contactA.fullname,
                contactA.annualincome,
                contactA.jobtitle
              );
              console.log("Contact URI: %s", Sdk.SampleVariables.contactAltUri);
            })
            .then(function () {
              // Setup for next request.
              //Similarly, the December 2016 update (v8.2) also enables returning selected properties
              //after an update operation (PATCH), with the 'Prefer: return=representation' header.
              var contactAlt = {};
              contactAlt.jobtitle = "Senior Developer";
              contactAlt.annualincome = 95000;
              contactAlt.description = "MS Azure and Dataverse Specialist";
              var properties = [
                "fullname",
                "annualincome",
                "jobtitle",
                "description",
              ].join();
              var query = "?$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: 48000.0,
      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 Dataverse Web API
Create a table row using the Web API
Retrieve a table row using the Web API
Update and delete table rows 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)