How to check if a list item exists or not in SharePoint 2013 using javascript

Question

I have created one custom form and insert data into one list.I want to check before data insert into the list if the data exists in list or not .

Answer 1

var clientContext = SP.ClientContext.get_current();     
list = clientContext.get_web().get_lists().getByTitle('ListName');           
var skillcamlQuery = new SP.CamlQuery();        
//skillcamlQuery.set_viewXml("<View><Query><Where><And><Eq><FieldRef Name='Title' /><Value Type='Text'>"+VariableName+"</Value></Eq><Eq><FieldRef Name='BusinessDomain' /><Value Type='Text'>"+VariableName+"</Value></Eq></And></Where></Query></View>");

skillcamlQuery.set_viewXml("<View><Query><Where><Eq><FieldRef Name='Title' /><Value Type='Text'>"+VariableName+"</Value></Eq></Where></Query></View>");
this.skillcollListItem = list.getItems(skillcamlQuery);
//clientContext.load(list);         
clientContext.load(skillcollListItem);

var callback = clientContext.executeQueryAsync(Function.createDelegate(this, function(){ _returnParam= onValidateClientSucceeded();}),Function.createDelegate(this, function(){ _returnParam = onValidateClientFailed();}));            







function onValidateClientSucceeded(sender, args)
  {     

        var flg = 0;


        if(skillcollListItem.get_count() >= 1)
        {
            flg = 1;            
        }
        else
        {


        }


  }

     function onValidateClientFailed(sender, args)
     { 
         alert('Request failed. ' + args.get_message() + '\n' + args.get_stackTrace());
         return false;
     }

Answer 2

Hello I had the exact same requirement a few days ago. I had to check if a value in one field existed in an item in another list and do this validation when user is saving the form. So the field in this example is eventdate and the field in the second list is time2 also i run this validation when a value in the first form is yes this field is demofield. Basically what this code does is if a demo field is yes it goes and checks in a list called demotrainingroom2 if time2 is equal to eventdate on every time. For this you need jquery and SPUtility.js. Check this fiddle

Answer 3

try the below code hope this will be helpfull.

 var hostWebUrl = decodeURIComponent(getQueryStringParameter('SPHostUrl'));//getting host URL

    var appWebUrl = decodeURIComponent(getQueryStringParameter('SPAppWebUrl'));//getting hosted app web URL

    var ctx = new SP.ClientContext(appWebUrl);//Get the SharePoint Context object based upon the URL  



    var appCtxSite = new SP.AppContextSite(ctx, hostWebUrl);

    var web = appCtxSite.get_web(); //Get the Site   

    var MyList = web.get_lists().getByTitle("MyList");// hosted list

    function getQueryStringParameter(urlParameterKey) {
        var params = document.URL.split('?')[1].split('&');
        var strParams = '';
        for (var i = 0; i < params.length; i = i + 1) {
            var singleParam = params[i].split('=');
            if (singleParam[0] == urlParameterKey)
                return decodeURIComponent(singleParam[1]);
        }
    }

    function getItemCount()
    {
     var query = new SP.CamlQuery();
     var items = MyList.getItems(query);
            ctx.load(items);
        ctx.executeQueryAsync(
            Function.createDelegate(this, function () {
              var count = items.get_count();
               -
               -
               -(your code will go here according to count)
               -
               -
               -
            }),
            Function.createDelegate(this, function () {
                alert('Request failed. ' + args.get_message() + '\n' + args.get_stackTrace());
            })
            );
    }
    $(document).ready(function () {
    getItemCount();
    });