How to get list items using Ajax and rest services

Question

Please let me know which "query" to be used...i just copied a sample code from net... please guide me as I am new to ajax and sharepoint

function getListItems(url, listname, query, complete, failure) {

    // Executing our items via an ajax request
    $.ajax({
        url: url + "/_api/web/lists/getbytitle('" + listname + "')/items" + query,
        method: "GET",
        headers: { "Accept": "application/json; odata=verbose" },
        success: function (data) {
            complete(data); // Returns JSON collection of the results
        },
        error: function (data) {
            failure(data);
        }
    });

}

Answer 1

Here you can use any of the query but before that you must be clear with your own requirement. If you want to get data with specific parameter (like you want to filter your data) then you can use the following code

Here i am just updating your code to pass the fieldname and fieldvalue. ( here i am assuming your list contain only one record, in case of multiple record you need to iterate the loop)

function getListItems(url, listname,fieldname, fieldvalue, complete, failure) {

    // Executing our items via an ajax request
    $.ajax({
        url: url + "/_api/web/lists/getbytitle('" + listname + "')/items?$filter= '" + fieldname + "' eq '" + fieldvalue,
        method: "GET",
        headers: { "Accept": "application/json; odata=verbose" },
        success: function (data) {
        if(data.length > 0){
                var value1 = data[0].fieldName; // this value1 you can assign it into your textbox
        }},
        error: function (data) {
            failure(data);
        }
    });
    }

Let me know whether this helps you or not.

Answer 2

You can build your query in several ways and as per your need. But before coping code you have to understand your requirement as well rest api in 2013. Have a look in my article to get started.

CRUD Operation to List Using SharePoint 2013 Rest API

Answer 3

query ="?$select=ID,Title"
url: _spPageContextInfo.webAbsoluteUrl+ "/_api/web/lists/getbytitle('" + listname + "')/items" + query,

ID and Title are the column names of the SharePoint list specified(list name).

_spPageContextInfo.webAbsoluteUrl gives the url of SharePoint.

In success function you will get the ID,Title etc

    success: function (data) {
             for (var i = 0; i < data.d.results.length; i++) {  
             console.log("Title: "+data.d.results[i].Title);
             console.log("ID: "+data.d.results[i].ID);
}

the above codes iterate in each row of SP List