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Posts Tagged ‘WCF’

Insert multiple oData records with a single post

6 February 2011 Leave a comment

A few months ago I was playing around with some user interface ideas. I used the jQuery sortable which will save to my oData service after the user had made a change. This caused multiple posts to the database, depending on the amount of items added, removed or reordered should the user navigate away before it was all completed.
After some searching I found a way around this which I decided to play around with again today for a project I will be doing soon. The idea is to combine all the updates/inserts into a sequence and then submit it in a single post. This will make it a lot quicker and also have a lot less code to display a single message when all the updates are complete.

This post will not go into much detail about getting the whole lot set up, so here is what you need already set up:

  • ASP.NET website building and running
  • WCF Data Service set up to return values when queried through the browser
  • MS AJAX Toolkit (Had to download the source to get all the .js libraries I needed)

For the sake of not struggling I copied all the files from the .\MS Ajax\SampleWebSites\AjaxClientWebSite\Scripts\MicrosoftAjax folder into my website’s Scripts folder and referenced only Start.debug.js (or Start.js for release). This takes care of loading all the rest of the required libraries.

My data service was called TestDataService.svc with a single table containing two columns since this was just the bare minimum to get my head around it again.

In my html page I have the following code to load, display and insert data.

    
    
        // We require this library
        Sys.require([Sys.components.dataView, Sys.components.openDataContext, Sys.components.openDataServiceProxy]);
        
        // A reference to our service
        var exampleService;

        // Page loaded and DOM ready
        Sys.onReady(function () {
            // Create the proxy to our data service
            exampleService = new Sys.Data.OpenDataServiceProxy("/TestDataService.svc");
            // Load the data from the service
            loadData();
        });

        function loadData() {
            // Query the service
            exampleService.query("/testTables", cbSuccess, cbFailure);
        }

        // Success callback for the loadData query
        function cbSuccess(result, context, operation, userContext) {
            // Clear the list
            $("#dbData").children().remove();
            // Add all the items from the database/service to the list
            $.each(result, function (index, row) {
                $("#dbData").append("<li>" + row.name + ": " + row.value + "</li>");
            });
        }

        // Failure callback for the loadData query
        function cbFailure() {
            alert("Error contacting service");
        }

        // Insert multiple recors into the database using a single post
        function insertMultiple() {
            // Sequence action for inserting data
            var actionSequence = exampleService.createActionSequence();
            // Creating 3 records
            for (var i = 0; i &lt; 3; i++) {
                var tmpData = {
                    name: "Sequence" + i, // Column name for the table
                    value: "" + i // Column name for the table
                };
                // Add the freshly create item to the sequence for testTable
                actionSequence.addInsertAction(tmpData, "/testTables");
            }
            // Execute the sequence
            actionSequence.execute(cbInsertComplete, "Inserted all three records");
        }

        // Success callback for the bulk insert
        function cbInsertComplete(results) {
            // Results returned after successful insert as _result. 
            $.each(results, function (index, row) {
                $("#dbData").append("<li>" + row._result.name + ": " + row._result.value + "</li>");
            });
        }
    

There is not much to the HTML

        <p>
            <ul id="dbData">
                        <!-- Data gets loaded here -->
            </ul>
        </p>
        <p>            
            <input id="Button2" type="button" value="Reload Data" onclick="loadData();" />
            <input id="Button1" type="button" value="Insert Data" onclick="insertMultiple();" />
        </p>

As you can see in the image below, when running this through FireBug you can see the first request to load the data which is currently empty, then there is a single post which posts the data and get the results back. We use the results to add the new data to the list.

This code is a very rough guide to executing a sequence of actions using oData services and should not be used as is in a live environment. No error checking is done and no best practices are followed in this post, it is purely the very basics to getting started.

If you would like more detailed information then please do contact me, I will be more than happy to help where I can.