Search Results

Search found 93388 results on 3736 pages for 'code structure'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 593/3736 | < Previous Page | 589 590 591 592 593 594 595 596 597 598 599 600  | Next Page >

  • What is Database Continuous Integration?

    - by SQLDev
    Although not everyone is practicing continuous integration, many have at least heard of the concept. A recent poll on www.simple-talk.com indicates that 40% of respondents are employing the technique. It is widely accepted that the earlier issues are identified in the development process, the lower the cost to the development process. The worst case scenario, of course, is for the bug to be found by the customer following the product release. A number of Agile development best practices have evolved to combat this problem early in the development process, including pair programming, code inspections and unit testing. Continuous integration is one such Agile concept that tackles the problem at the point of committing a change to source control. This can alternatively be run on a regular schedule. This triggers a sequence of events that compiles the code and performs a variety of tests. Often the continuous integration process is regarded as a build validation test, and if issues were to be identified at this stage, the testers would simply not 'waste their time ' and touch the build at all. Such a ‘broken build’ will trigger an alert and the development team’s number one priority should be to resolve the issue. How application code is compiled and tested as part of continuous integration is well understood. However, this isn’t so clear for databases. Indeed, before I cover the mechanics of implementation, we need to decide what we mean by database continuous integration. For me, database continuous integration can be implemented as one or more of the following: 1)      Your application code is being compiled and tested. You therefore need a database to be maintained at the corresponding version. 2)      Just as a valid application should compile, so should the database. It should therefore be possible to build a new database from scratch. 3)     Likewise, it should be possible to generate an upgrade script to take your already deployed databases to the latest version. I will be covering these in further detail in future blogs. In the meantime, more information can be found in the whitepaper linked off www.red-gate.com/ci If you have any questions, feel free to contact me directly or post a comment to this blog post.

    Read the article

  • WPF TextBlock refresh in real time

    - by TheOnlyBrien
    I'm new to C#, in fact, this is one of the first projects I've tried to start on my own. I am curious why the TextBlock will not refresh with the following code? The WPF window does not even show up when I add the "while" loop to the code. I just want this to have a real time display of the days since I was born. Please help me out or give me constructive direction. using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows; using System.Windows.Controls; using System.Windows.Data; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Imaging; using System.Windows.Navigation; using System.Windows.Shapes; namespace daysAliveWPF { /// <summary> /// Interaction logic for MainWindow.xaml /// </summary> public partial class MainWindow : Window { public MainWindow() { InitializeComponent(); DateTime myBirthday = new DateTime(1984, 01, 19); while (true) { TimeSpan daysAlive = DateTime.Now.Subtract(myBirthday); MyTextBlock.Text = daysAlive.TotalDays.ToString(); } } } } Similar code has worked in a Console Window application, so I don't understand what's going on here. Console Application code snip that did work is: using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace DisplayRealTime { class Program { static void Main(string[] args) { DateTime myBirthday = new DateTime(1984, 06, 19); while (true) { TimeSpan daysAlive = DateTime.Now.Subtract(myBirthday); Console.Write("\rTotal Days Alive: {0}", daysAlive.TotalDays.ToString(".#####")); } } } } Thank you!

    Read the article

  • Resizing text in an HTML 5 page using JQuery

    - by nikolaosk
    This is going to be the ninth post in a series of posts regarding HTML 5. You can find the other posts here, here , here , here, here , here , here and here.In this post I will demonstrate how to implement a very common feature found in websites today, enabling the visitor to increase or decrease the font size of a page. You can use the JQuery code I will write in this post for HTML pages which do not follow the HTML 5 standard. As I said earlier we need to write JavaScript to implement this functionality.I will use the very popular JQuery Library. Please download the library (minified version) from http://jquery.com/downloadIn this hands-on example I will be using Expression Web 4.0.This application is not a free application. You can use any HTML editor you like.You can use Visual Studio 2012 Express edition. You can download it here. The HTML markup for the page follows. <!DOCTYPE html><html lang="en">  <head>    <title>HTML 5, CSS3 and JQuery</title>        <meta http-equiv="Content-Type" content="text/html;charset=utf-8" >    <link rel="stylesheet" type="text/css" href="style.css">     <script type="text/javascript" src="jquery-1.8.2.min.js">        </script><script type="text/javascript">$(function() {    $('a').click(function() {        var getfont = $('p').css('font-size');        var mynum = parseFloat(getfont, 10);        var newmwasure = getfont.slice(-2);                $('p').css('font-size', mynum / 1.2 + newmwasure);                if(this.id == 'increase') {            $('p').css('font-size', mynum * 1.4 + newmwasure);        }     })    })</script>       </head>  <body>      <div id="header">      <h1>Learn cutting edge technologies</h1>      <h2>HTML 5, JQuery, CSS3</h2>    </div>    <div id="resize">    <a href="" id="increase">Increase Font</a>       |        <a href="" id="decrease">Decrease Font</a>        </div>        <div id="main">          <h2>HTML 5</h2>                        <article>          <p>            HTML5 is the latest version of HTML and XHTML. The HTML standard defines a single language that can be written in HTML and XML. It attempts to solve issues found in previous iterations of HTML and addresses the needs of Web Applications, an area previously not adequately covered by HTML.          </p>          </article>      </div>             </body>  </html>  There is nothing difficult or fancy in the HTML markup above. I have a link to the external JQuery library and the JQuery code is included inside the .html page.I have two links on this page that will increase/decrease the font size of the contents enclosed inside the <p></p> tags.Let me explain what the JQuery code does.When the user clicks on the link, I store in a variable the current font size of the <p> element that I get back from the CSS function. var getfont = $('p').css('font-size'); So now we have the original value. That will return a value like "16px" "1.2em".Then I need to get the unit of measurement (px,em).I use the slice() function. var newmwasure = getfont.slice(-2); Then I want to get only the numeric part of the returning value.I do that using the parseFloat() function.Have a look at the parseFloat() function.Finally with this bit of code I choose a ratio (I am devising a very simple algorithm for increasing and decreasing) and apply it to the <p> element. I still use the CSS function. You can get but also set the font size for a particular element with the CSS function.So I check for the id=increase and if this matches I will increase the font size of the <p> element.If it does not match we will decrease the font size.   $('p').css('font-size', mynum / 1.2 + newmwasure);                if(this.id == 'increase') {            $('p').css('font-size', mynum * 1.4 + newmwasure);  The code for the css file (style.css) followsbody{background-color:#eaeaea;}p{font-size:0.8em;font-family:Tahoma;}#resize{width:200px;background-color:#dadada;}#resize a {text-decoration:none;}The above CSS rules are very easy to understand. Now I save all my work.I view my page on the browser for the first time.Have a look at the picture below Now I increase the font size by clicking the respective linkHave a look at the picture below  Finally I decrease the font size by clicking on the respective linkHave a look at the picture below   Once more we see that the power and simplicity of JQuery library enables us to write less code but accomplish a lot at the same time. Hope it helps!!  

    Read the article

  • More Fun With Math

    - by PointsToShare
    More Fun with Math   The runaway student – three different ways of solving one problem Here is a problem I read in a Russian site: A student is running away. He is moving at 1 mph. Pursuing him are a lion, a tiger and his math teacher. The lion is 40 miles behind and moving at 6 mph. The tiger is 28 miles behind and moving at 4 mph. His math teacher is 30 miles behind and moving at 5 mph. Who will catch him first? Analysis Obviously we have a set of three problems. They are all basically the same, but the details are different. The problems are of the same class. Here is a little excursion into computer science. One of the things we strive to do is to create solutions for classes of problems rather than individual problems. In your daily routine, you call it re-usability. Not all classes of problems have such solutions. If a class has a general (re-usable) solution, it is called computable. Otherwise it is unsolvable. Within unsolvable classes, we may still solve individual (some but not all) problems, albeit with different approaches to each. Luckily the vast majority of our daily problems are computable, and the 3 problems of our runaway student belong to a computable class. So, let’s solve for the catch-up time by the math teacher, after all she is the most frightening. She might even make the poor runaway solve this very problem – perish the thought! Method 1 – numerical analysis. At 30 miles and 5 mph, it’ll take her 6 hours to come to where the student was to begin with. But by then the student has advanced by 6 miles. 6 miles require 6/5 hours, but by then the student advanced by another 6/5 of a mile as well. And so on and so forth. So what are we to do? One way is to write code and iterate it until we have solved it. But this is an infinite process so we’ll end up with an infinite loop. So what to do? We’ll use the principles of numerical analysis. Any calculator – your computer included – has a limited number of digits. A double floating point number is good for about 14 digits. Nothing can be computed at a greater accuracy than that. This means that we will not iterate ad infinidum, but rather to the point where 2 consecutive iterations yield the same result. When we do financial computations, we don’t even have to go that far. We stop at the 10th of a penny.  It behooves us here to stop at a 10th of a second (100 milliseconds) and this will how we will avoid an infinite loop. Interestingly this alludes to the Zeno paradoxes of motion – in particular “Achilles and the Tortoise”. Zeno says exactly the same. To catch the tortoise, Achilles must always first come to where the tortoise was, but the tortoise keeps moving – hence Achilles will never catch the tortoise and our math teacher (or lion, or tiger) will never catch the student, or the policeman the thief. Here is my resolution to the paradox. The distance and time in each step are smaller and smaller, so the student will be caught. The only thing that is infinite is the iterative solution. The race is a convergent geometric process so the steps are diminishing, but each step in the solution takes the same amount of effort and time so with an infinite number of steps, we’ll spend an eternity solving it.  This BTW is an original thought that I have never seen before. But I digress. Let’s simply write the code to solve the problem. To make sure that it runs everywhere, I’ll do it in JavaScript. function LongCatchUpTime(D, PV, FV) // D is Distance; PV is Pursuers Velocity; FV is Fugitive’ Velocity {     var t = 0;     var T = 0;     var d = parseFloat(D);     var pv = parseFloat (PV);     var fv = parseFloat (FV);     t = d / pv;     while (t > 0.000001) //a 10th of a second is 1/36,000 of an hour, I used 1/100,000     {         T = T + t;         d = t * fv;         t = d / pv;     }     return T;     } By and large, the higher the Pursuer’s velocity relative to the fugitive, the faster the calculation. Solving this with the 10th of a second limit yields: 7.499999232000001 Method 2 – Geometric Series. Each step in the iteration above is smaller than the next. As you saw, we stopped iterating when the last step was small enough, small enough not to really matter.  When we have a sequence of numbers in which the ratio of each number to its predecessor is fixed we call the sequence geometric. When we are looking at the sum of sequence, we call the sequence of sums series.  Now let’s look at our student and teacher. The teacher runs 5 times faster than the student, so with each iteration the distance between them shrinks to a fifth of what it was before. This is a fixed ratio so we deal with a geometric series.  We normally designate this ratio as q and when q is less than 1 (0 < q < 1) the sum of  + … +  is  – 1) / (q – 1). When q is less than 1, it is easier to use ) / (1 - q). Now, the steps are 6 hours then 6/5 hours then 6/5*5 and so on, so q = 1/5. And the whole series is multiplied by 6. Also because q is less than 1 , 1/  diminishes to 0. So the sum is just  / (1 - q). or 1/ (1 – 1/5) = 1 / (4/5) = 5/4. This times 6 yields 7.5 hours. We can now continue with some algebra and take it back to a simpler formula. This is arduous and I am not going to do it here. Instead let’s do some simpler algebra. Method 3 – Simple Algebra. If the time to capture the fugitive is T and the fugitive travels at 1 mph, then by the time the pursuer catches him he travelled additional T miles. Time is distance divided by speed, so…. (D + T)/V = T  thus D + T = VT  and D = VT – T = (V – 1)T  and T = D/(V – 1) This “strangely” coincides with the solution we just got from the geometric sequence. This is simpler ad faster. Here is the corresponding code. function ShortCatchUpTime(D, PV, FV) {     var d = parseFloat(D);     var pv = parseFloat (PV);     var fv = parseFloat (FV);     return d / (pv - fv); } The code above, for both the iterative solution and the algebraic solution are actually for a larger class of problems.  In our original problem the student’s velocity (speed) is 1 mph. In the code it may be anything as long as it is less than the pursuer’s velocity. As long as PV > FV, the pursuer will catch up. Here is the really general formula: T = D / (PV – FV) Finally, let’s run the program for each of the pursuers.  It could not be worse. I know he’d rather be eaten alive than suffering through yet another math lesson. See the code run? Select  “Catch Up Time” in www.mgsltns.com/games.htm The host is running on Unix, so the link is case sensitive. That’s All Folks

    Read the article

  • Web-Cam SecureChat

    This article will explain how to create a simple chat program using this remoting technology, which supports web-cam and sending files.

    Read the article

  • Why do I get this file loading exception when trying to draw sprites with libgdx?

    - by BluFire
    I'm having trouble with the "Drawing Images" section on the libgdx tutorial. I set up the documents completely and I typed the code as follows: public class Game implements ApplicationListener { public static final String LOG = Game.class.getSimpleName(); private FPSLogger fpsLogger; private SpriteBatch batch; private Texture texture; private Sprite sprite; private TextureRegion region; //removed irrelevant code for this question... @Override public void render() { texture = new Texture(Gdx.files.internal("android.png")); region = new TextureRegion(texture, 20, 20, 50, 50); sprite = new Sprite(texture, 20, 20, 50, 50); sprite.setPosition(10, 10); sprite.setRotation(45); Gdx.gl.glClearColor(0f, 1f, 0f, 1f); Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT); batch.begin(); batch.draw(texture,10,10); batch.draw(region,10,10); sprite.draw(batch); batch.end(); // output the current FPS fpsLogger.log(); } } I went through the tutorial on the website but when I run the code I get errors: Exception in thread "LWJGL Application" com.badlogic.gdx.utils.GdxRuntimeException: Couldn't load file: android.png at com.badlogic.gdx.graphics.Pixmap.<init>(Pixmap.java:137) at com.badlogic.gdx.graphics.glutils.FileTextureData.prepare(FileTextureData.java:55) at com.badlogic.gdx.graphics.Texture.load(Texture.java:175) at com.badlogic.gdx.graphics.Texture.create(Texture.java:159) at com.badlogic.gdx.graphics.Texture.<init>(Texture.java:133) at com.badlogic.gdx.graphics.Texture.<init>(Texture.java:122) at com.game.Game.render(Game.java:46) at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop (LwjglApplication.java:163) at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:113) Caused by: com.badlogic.gdx.utils.GdxRuntimeException: File not found: android.png (Internal) at com.badlogic.gdx.files.FileHandle.read(FileHandle.java:108) at com.badlogic.gdx.files.FileHandle.length(FileHandle.java:364) at com.badlogic.gdx.files.FileHandle.readBytes(FileHandle.java:156) at com.badlogic.gdx.graphics.Pixmap.<init>(Pixmap.java:134) ... 8 more I set the android.png in my assests folder in my android project linking it to the desktop one, I don't understand what I'm doing wrong. What is making these errors? FIX. Weird ending.this was the plus where the sprite is suppose to look like. The top right corner of the next image should look like, the bottom left is what turned out in the code. I'm think it was because of the texture region but I'm not 100%. Can somebody explain why it is really warped? I thought the changes I made in the coding will just change position/rotation, rather then a change in the image.

    Read the article

  • Compiling and Running Handbrake in Ubuntu

    <b>Packt Publishing: </b>"Handbrake is considered the Swiss Army knife of video conversion tools. Running on the three major operating system platforms, Handbrake can open a huge variety of formats, including common ones that others can't handle (like the titles in the MPEG TS structure of a DVD)."

    Read the article

  • YouTube Developers Live: Freebase API for YouTube Developers

    YouTube Developers Live: Freebase API for YouTube Developers In this video, a special guest from the Freebase team, Shawn Simister is giving an overview of the Freebase and Topics API for YouTube API V3. To learn more about the Freebase API, see wiki.freebase.com For YouTube API V3, you can find more information here: developers.google.com Catch us live on Wednesdays, 10am Pacific at developers.google.com From: GoogleDevelopers Views: 87 18 ratings Time: 28:00 More in Science & Technology

    Read the article

  • Using Sitecore RenderingContext Parameters as MVC controller action arguments

    - by Kyle Burns
    I have been working with the Technical Preview of Sitecore 6.6 on a project and have been for the most part happy with the way that Sitecore (which truly is an MVC implementation unto itself) has been expanded to support ASP.NET MVC. That said, getting up to speed with the combined platform has not been entirely without stumbles and today I want to share one area where Sitecore could have really made things shine from the "it just works" perspective. A couple days ago I was asked by a colleague about the usage of the "Parameters" field that is defined on Sitecore's Controller Rendering data template. Based on the standard way that Sitecore handles a field named Parameters, I was able to deduce that the field expected key/value pairs separated by the "&" character, but beyond that I wasn't sure and didn't see anything from a documentation perspective to guide me, so it was time to dig and find out where the data in the field was made available. My first thought was that it would be really nice if Sitecore handled the parameters in this field consistently with the way that ASP.NET MVC handles the various parameter collections on the HttpRequest object and automatically maps them to parameters of the action method executing. Being the hopeful sort, I configured a name/value pair on one of my renderings, added a parameter with matching name to the controller action and fired up the bugger to see... that the parameter was not populated. Having established that the field's value was not going to be presented to me the way that I had hoped it would, the next assumption that I would work on was that Sitecore would handle this field similar to how they handle other similar data and would plug it into some ambient object that I could reference from within the controller method. After a considerable amount of guessing, testing, and cracking code open with Redgate's Reflector (a must-have companion to Sitecore documentation), I found that the most direct way to access the parameter was through the ambient RenderingContext object using code similar to: string myArgument = string.Empty; var rc = Sitecore.Mvc.Presentation.RenderingContext.CurrentOrNull; if (rc != null) {     var parms = rc.Rendering.Parameters;     myArgument = parms["myArgument"]; } At this point, we know how this field is used out of the box from Sitecore and can provide information from Sitecore's Content Editor that will be available when the controller action is executing, but it feels a little dirty. In order to properly test the action method I would have to do a lot of setup work and possible use an isolation framework such as Pex and Moles to get at a value that my action method is dependent upon. Notice I said that my method is dependent upon the value but in order to meet that dependency I've accepted another dependency upon Sitecore's RenderingContext.  I'm a big believer in, when possible, ensuring that any piece of code explicitly advertises dependencies using the method signature, so I found myself still wanting this to work the same as if the parameters were in the request route, querystring, or form by being able to add a myArgument parameter to the action method and have this parameter populated by the framework. Lucky for us, the ASP.NET MVC framework is extremely flexible and provides some easy to grok and use extensibility points. ASP.NET MVC is able to provide information from the request as input parameters to controller actions because it uses objects which implement an interface called IValueProvider and have been registered to service the application. The most basic statement of responsibility for an IValueProvider implementation is "I know about some data which is indexed by key. If you hand me the key for a piece of data that I know about I give you that data". When preparing to invoke a controller action, the framework queries registered IValueProvider implementations with the name of each method argument to see if the ValueProvider can supply a value for the parameter. (the rest of this post will assume you're working along and make a lot more sense if you do) Let's pull Sitecore out of the equation for a second to simplify things and create an extremely simple IValueProvider implementation. For this example, I first create a new ASP.NET MVC3 project in Visual Studio, selecting "Internet Application" and otherwise taking defaults (I'm assuming that anyone reading this far in the post either already knows how to do this or will need to take a quick run through one of the many available basic MVC tutorials such as the MVC Music Store). Once the new project is created, go to the Index action of HomeController.  This action sets a Message property on the ViewBag to "Welcome to ASP.NET MVC!" and invokes the View, which has been coded to display the Message. For our example, we will remove the hard coded message from this controller (although we'll leave it just as hard coded somewhere else - this is sample code). For the first step in our exercise, add a string parameter to the Index action method called welcomeMessage and use the value of this argument to set the ViewBag.Message property. The updated Index action should look like: public ActionResult Index(string welcomeMessage) {     ViewBag.Message = welcomeMessage;     return View(); } This represents the entirety of the change that you will make to either the controller or view.  If you run the application now, the home page will display and no message will be presented to the user because no value was supplied to the Action method. Let's now write a ValueProvider to ensure this parameter gets populated. We'll start by creating a new class called StaticValueProvider. When the class is created, we'll update the using statements to ensure that they include the following: using System.Collections.Specialized; using System.Globalization; using System.Web.Mvc; With the appropriate using statements in place, we'll update the StaticValueProvider class to implement the IValueProvider interface. The System.Web.Mvc library already contains a pretty flexible dictionary-like implementation called NameValueCollectionValueProvider, so we'll just wrap that and let it do most of the real work for us. The completed class looks like: public class StaticValueProvider : IValueProvider {     private NameValueCollectionValueProvider _wrappedProvider;     public StaticValueProvider(ControllerContext controllerContext)     {         var parameters = new NameValueCollection();         parameters.Add("welcomeMessage", "Hello from the value provider!");         _wrappedProvider = new NameValueCollectionValueProvider(parameters, CultureInfo.InvariantCulture);     }     public bool ContainsPrefix(string prefix)     {         return _wrappedProvider.ContainsPrefix(prefix);     }     public ValueProviderResult GetValue(string key)     {         return _wrappedProvider.GetValue(key);     } } Notice that the only entry in the collection matches the name of the argument to our HomeController's Index action.  This is the important "secret sauce" that will make things work. We've got our new value provider now, but that's not quite enough to be finished. Mvc obtains IValueProvider instances using factories that are registered when the application starts up. These factories extend the abstract ValueProviderFactory class by initializing and returning the appropriate implementation of IValueProvider from the GetValueProvider method. While I wouldn't do so in production code, for the sake of this example, I'm going to add the following class definition within the StaticValueProvider.cs source file: public class StaticValueProviderFactory : ValueProviderFactory {     public override IValueProvider GetValueProvider(ControllerContext controllerContext)     {         return new StaticValueProvider(controllerContext);     } } Now that we have a factory, we can register it by adding the following line to the end of the Application_Start method in Global.asax.cs: ValueProviderFactories.Factories.Add(new StaticValueProviderFactory()); If you've done everything right to this point, you should be able to run the application and be presented with the home page reading "Hello from the value provider!". Now that you have the basics of the IValueProvider down, you have everything you need to enhance your Sitecore MVC implementation by adding an IValueProvider that exposes values from the ambient RenderingContext's Parameters property. I'll provide the code for the IValueProvider implementation (which should look VERY familiar) and you can use the work we've already done as a reference to create and register the factory: public class RenderingContextValueProvider : IValueProvider {     private NameValueCollectionValueProvider _wrappedProvider = null;     public RenderingContextValueProvider(ControllerContext controllerContext)     {         var collection = new NameValueCollection();         var rc = RenderingContext.CurrentOrNull;         if (rc != null && rc.Rendering != null)         {             foreach(var parameter in rc.Rendering.Parameters)             {                 collection.Add(parameter.Key, parameter.Value);             }         }         _wrappedProvider = new NameValueCollectionValueProvider(collection, CultureInfo.InvariantCulture);         }     public bool ContainsPrefix(string prefix)     {         return _wrappedProvider.ContainsPrefix(prefix);     }     public ValueProviderResult GetValue(string key)     {         return _wrappedProvider.GetValue(key);     } } In this post I've discussed the MVC IValueProvider used to map data to controller action method arguments and how this can be integrated into your Sitecore 6.6 MVC solution.

    Read the article

  • SQL SERVER – Using expressor Composite Types to Enforce Business Rules

    - by pinaldave
    One of the features that distinguish the expressor Data Integration Platform from other products in the data integration space is its concept of composite types, which provide an effective and easily reusable way to clearly define the structure and characteristics of data within your application.  An important feature of the composite type approach is that it allows you to easily adjust the content of a record to its ultimate purpose.  For example, a record used to update a row in a database table is easily defined to include only the minimum set of columns, that is, a value for the key column and values for only those columns that need to be updated. Much like a class in higher level programming languages, you can also use the composite type as a way to enforce business rules onto your data by encapsulating a datum’s name, data type, and constraints (for example, maximum, minimum, or acceptable values) as a single entity, which ensures that your data can not assume an invalid value.  To what extent you use this functionality is a decision you make when designing your application; the expressor design paradigm does not force this approach on you. Let’s take a look at how these features are used.  Suppose you want to create a group of applications that maintain the employee table in your human resources database. Your table might have a structure similar to the HumanResources.Employee table in the AdventureWorks database.  This table includes two columns, EmployeID and rowguid, that are maintained by the relational database management system; you cannot provide values for these columns when inserting new rows into the table. Additionally, there are columns such as VacationHours and SickLeaveHours that you might choose to update for all employees on a monthly basis, which justifies creation of a dedicated application. By creating distinct composite types for the read, insert and update operations against this table, you can more easily manage this table’s content. When developing this application within expressor Studio, your first task is to create a schema artifact for the database table.  This process is completely driven by a wizard, only requiring that you select the desired database schema and table.  The resulting schema artifact defines the mapping of result set records to a record within the expressor data integration application.  The structure of the record within the expressor application is a composite type that is given the default name CompositeType1.  As you can see in the following figure, all columns from the table are included in the result set and mapped to an identically named attribute in the default composite type. If you are developing an application that needs to read this table, perhaps to prepare a year-end report of employees by department, you would probably not be interested in the data in the rowguid and ModifiedDate columns.  A typical approach would be to drop this unwanted data in a downstream operator.  But using an alternative composite type provides a better approach in which the unwanted data never enters your application. While working in expressor  Studio’s schema editor, simply create a second composite type within the same schema artifact, which you could name ReadTable, and remove the attributes corresponding to the unwanted columns. The value of an alternative composite type is even more apparent when you want to insert into or update the table.  In the composite type used to insert rows, remove the attributes corresponding to the EmployeeID primary key and rowguid uniqueidentifier columns since these values are provided by the relational database management system. And to update just the VacationHours and SickLeaveHours columns, use a composite type that includes only the attributes corresponding to the EmployeeID, VacationHours, SickLeaveHours and ModifiedDate columns. By specifying this schema artifact and composite type in a Write Table operator, your upstream application need only deal with the four required attributes and there is no risk of unintentionally overwriting a value in a column that does not need to be updated. Now, what about the option to use the composite type to enforce business rules?  If you review the composition of the default composite type CompositeType1, you will note that the constraints defined for many of the attributes mirror the table column specifications.  For example, the maximum number of characters in the NationaIDNumber, LoginID and Title attributes is equivalent to the maximum width of the target column, and the size of the MaritalStatus and Gender attributes is limited to a single character as required by the table column definition.  If your application code leads to a violation of these constraints, an error will be raised.  The expressor design paradigm then allows you to handle the error in a way suitable for your application.  For example, a string value could be truncated or a numeric value could be rounded. Moreover, you have the option of specifying additional constraints that support business rules unrelated to the table definition. Let’s assume that the only acceptable values for marital status are S, M, and D.  Within the schema editor, double-click on the MaritalStatus attribute to open the Edit Attribute window.  Then click the Allowed Values checkbox and enter the acceptable values into the Constraint Value text box. The schema editor is updated accordingly. There is one more option that the expressor semantic type paradigm supports.  Since the MaritalStatus attribute now clearly specifies how this type of information should be represented (a single character limited to S, M or D), you can convert this attribute definition into a shared type, which will allow you to quickly incorporate this definition into another composite type or into the description of an output record from a transform operator. Again, double-click on the MaritalStatus attribute and in the Edit Attribute window, click Convert, which opens the Share Local Semantic Type window that you use to name this shared type.  There’s no requirement that you give the shared type the same name as the attribute from which it was derived.  You should supply a name that makes it obvious what the shared type represents. In this posting, I’ve overviewed the expressor semantic type paradigm and shown how it can be used to make your application development process more productive.  The beauty of this feature is that you choose when and to what extent you utilize the functionality, but I’m certain that if you opt to follow this approach your efforts will become more efficient and your work will progress more quickly.  As always, I encourage you to download and evaluate expressor Studio for your current and future data integration needs. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: CodeProject, Pinal Dave, PostADay, SQL, SQL Authority, SQL Documentation, SQL Query, SQL Server, SQL Tips and Tricks, SQLServer, T SQL, Technology

    Read the article

  • Exposer des modèles C++ imbriqués à QML, un article de Christophe Dumez traduit par Thibaut Cuvelier

    Bien que ce cas d'imbrication puisse sembler rare en pratique, le fait que XML n'ait pas de support direct pour les modèles arborescents rend l'utilisation de modèles C++ imbriqués très utile pour obtenir une structure en arbre. Un exemple de cas pratique où les modèles imbriqués sont utiles est le stockage de conversations Facebook. Un mur Facebook est constitué de notifications sociales (modèle racine), chacun pouvant avoir des commentaires (modèles internes). Exposer des modèles C++ imbriqués à QML...

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 589 590 591 592 593 594 595 596 597 598 599 600  | Next Page >