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  • ruby on rails w/ SQLServer

    - by jaydel
    I've heard from some people that RoR doesn't marry cleanly with SQLServer. We have a series of historical, standardization to use SQLServer but if we can push back with valid reasons we can move to another db. One person on the team wants MySql and another wants Postgres, etc. I'm trying to stay out of the religious wars and really understand what the pain point is with SQLServer. We're running the app server on a linux box, and the database will be on a windows box and the SQLServer that we're supposed to standardize on is 2008, if those details help any... thanks in advance!

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  • Progress Dialog on open activity

    - by GeeXor
    hey guys, i've a problem with progress dialog on opening an activity (called activity 2 in example). The activity 2 has a lot of code to execute in this OnCreate event. final ProgressDialog myProgressDialog = ProgressDialog.show(MyApp.this,getString(R.string.lstAppWait), getString(R.string.lstAppLoading), true); new Thread() { public void run() { runOnUiThread(new Runnable() { @Override public void run() { showApps(); } }); myProgressDialog.dismiss(); } }.start(); The showApps function launch activity 2. if i execute this code on my button click event on activity 1, i see the progress, but she doesn't move and afeter i have a black screen during 2 or 3 seconds the time for android to show the activity. If i execute this code in the OnCreate of Activity2 and if i replace the showApps by the code on OnCreate, Activity1 freeze 2 seconds, i don't see the progress dialog, and freeze again 2 seconds on activity 2 before seeing the result. An idea ?

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  • Skeleton framework spacing

    - by user1745014
    I tried to ask this question late lastnight but I was so sleepy i typed the question completely wrong. I'm looking to float my navigation to the right of its current position around 200px more, there is room but it wont move over. You can view the live code here - www.xronn.co.uk/hosting and here is an image to explain my issue a little more http://i.stack.imgur.com/JtL0C.png purple lines the 960px width of the site blue line shows the space free for the navigation to go and the red arrows of course shows which direction i want the navigation to go in (the right) Anyone got any clue why when I push to more to the right, the list starts to sit under each other

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  • Adding a border (Fixed3D) to an existing borderless application

    - by Aphelion
    Hi there, I have an .NET application that always starts itself with its border style to 'None', as it is supposed to be an full-screen application with a fixed resolution. However, i would like to add the window border (Fixed3D) to this window when the application starts so that I am able to move it around my desktop. My first idea was to have a tray app running, monitoring event messages, and somehow change the window style when this specific application starts. However, I am not sure if this will work and how to do this. Anyone that can point me in the right direction?

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  • How do I setup Eclipse to stop on the line an exception occured?

    - by Chris Persichetti
    Hi, How can I setup Eclipse to stop at the point an exception occurred. I have an Eclipse breakpoint setup to break on an exception. In the code example below, the problem I'm having is Eclipse tries to open the Integer source code. Is there any way to just have debugger break at the point shown in my code example? If I move down the stack trace, I will get to this line, it'd be nice if there's a way to do this without the "Source not found" window coming up. This can be done in Visual Studio, so it's driving me crazy not being able to find a way to do this in Eclipse. package com.test; public class QuickTest { public static void main(String[] args) { try { test(); } catch(NumberFormatException e) { System.out.println(e.getMessage()); } } private static void test() { String str = "notAnumber"; Integer.parseInt(str);//<----I want debugger to stop here } }

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  • Java spliting strings

    - by N0b
    Hi I've got a Java problem. I'm trying split a string when ever a " " occurs, for example the sentence test abc. Then move the first letter in each word from first to last. I got the moving the letter to work on the original string using String text = JOptionPane.showInputDialog(null,"Skriv in en normal text:"); char firstLetter = text.charAt(0); normal = text.substring(1,text.length()+0) + firstLetter; So my question is how would I split the string then start moving the letters around in each part of the cut string? Thanks in advance

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  • C++0x error : variable 'std::packaged_task<int> pt1' has initializer but incomplete type

    - by Eternal Learner
    Hi All, Below is a simple program in c++0x that makes use of packaged_task and futures. while compiling the program i get error : variable 'std::packaged_task pt1' has initializer but incomplete type the program is below #include #include using namespace std; int printFn() { for(int i = 0; i < 100; i++) { cout << "thread " << i << endl; } return 1; } int main() { packaged_task<int> pt1(&printFn); future<int> fut = pt1.get_future(); thread t(move(pt1)); t.detach(); int value = fut.get(); return 0; }

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  • Neural network for aproximation function for board game

    - by Pax0r
    I am trying to make a neural network for aproximation of some unkown function (for my neural network course). The problem is that this function has very many variables but many of them are not important (for example in [f(x,y,z) = x+y] z is not important). How could I design (and learn) network for this kind of problem? To be more specific the function is an evaluation function for some board game with unkown rules and I need to somehow learn this rules by experience of the agent. After each move the score is given to the agent so actually it needs to find how to get max score. I tried to pass the neighborhood of the agent to the network but there are too many variables which are not important for the score and agent is finding very local solutions.

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  • Slide Effect happening too many times

    - by Abs
    Hello all, I call this functions on onmouseover and onmouseout for several divs. //Takes effect on divs with id, 62,63,64,65... function slide_it(id){ $('#options_'+id).slideToggle('slow'); } The problem is that if I move my mouse over and then mouse out, then again, mouse over and then mouse out. If I do this several times, the slide effect happens the same number of times I moved my mouse over and out of the div, as expected. But I can't figure out how I can do this once? I can set a variable, but I have several divs that this function is used by and I can't think of a simple way of doing this rather than storing things into an array, but this is messy! I really appreciate any help on this that is simple to implement! Thanks all for any help

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  • Need help on understanding Mobile First concept

    - by RhymeGuy
    So, I worked on responsive sites before but I'm on my way to build my first responsive site now. I opened some articles on the subject, and boom: Mobile First.. I have no idea how I skipped that concept till now. From the beginning I cant seem to understand whole thing (except that number of mobile devices will take out soon desktop computers) and here is why. How I'm supposed to know how my site will look for desktop version, if I design it for mobile first? I mean, on the smallest device I will have to eventually hide some content etc, how I'm supposed to know what to hide and move things, when I don't know how the site will look on bigger screen? Isn't stripping the things easier?!?! For me (right now), the Mobile First concept looks to me like building pyramid upside down.

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  • Easiest way to keep SSRS child elements in the same relative position when the parent is re-positioned?

    - by Mac
    I am trying to revise the layout of an SSRS report where I have several textboxes that are child elements of a rectangle. When I reposition the parent rectangle down by x, all of the child textboxes maintain the same absolute position. Their "Location" (defined relative to the parent) decreases by x. I then need to reposition the child textboxes. Additionally, if any of these ever has a negative "Location" then the parent rectangle is then repositioned back up by x. What is the easiest way to move everything in unison? I can Control-click everything and then drag them or use the arrow keys, but I want to position everything with precision and the "Location" field in the Properties window disappears when selecting more than one item. Is there a way I can avoid individually computing and typing in every "Location" value every time I have a small layout change? I am using SSRS (11.0.3360.12) within the Visual Studio 2012 Shell. Thanks!

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  • how to integrate my users database table with the aspnet_users table that comes with asp.net members

    - by ooo
    i have a database that already has a users table COLUMNS: userID - int loginName - string First - string Last - string i just installed the asp.net membership table. Right now all of my tables are joined into my users table foreign keyed into the "userId" field How do i integrate asp.net_users table into my schema? here are the ideas i thought of: Add a membership_id field to my users table and on new inserts, include that new field in my users table. This seems like the cleanest way as i dont need to break any existing relationships. break all existing relationship and move all of the fields in my user table into the asp.net_users table. This seems like a pain but ultimately will lead to the most simple, normalized solution any thoughts?

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  • how do I repaint an applet while moving a sprite?

    - by Nagrom_17
    I have a little java applet where I create 2 threads, one thread repaints and the other moves an image from a point to where the user clicks. The problem is that when I call the move function it loops until the image is where the user clicks but it wont repaint until I break out of the loop even though the thread doing the moving and the thread doing the painting are separate. shortened version of key points: my program is an applet using the paint() method I have 2 threads one moves an image and the other paints that image when I am moving the image it is in a while loop the painting thread is still calling repaint() but that is as far as the call goes, it never repaints thank you for your time.

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  • When open-sourcing a live Rails app, is it dangerous to leave the session key secret in source contr

    - by rspeicher
    I've got a Rails app that's been running live for some time, and I'm planning to open source it in the near future. I'm wondering how dangerous it is to leave the session key store secret in source control while the app is live. If it's dangerous, how do people usually handle this problem? I'd guess that it's easiest to just move the string to a text file that's ignored by the SCM, and read it in later. Just for clarity, I'm talking about this: # Your secret key for verifying cookie session data integrity. # If you change this key, all old sessions will become invalid! # Make sure the secret is at least 30 characters and all random, # no regular words or you'll be exposed to dictionary attacks. ActionController::Base.session = { :key => '_application_session', :secret => '(long, unique string)' } And while we're on the subject, is there anything else in a default Rails app that should be protected when open sourcing a live app?

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  • Create ordering in a MySQL table without using a number (because then it's hard to put something in

    - by user347256
    I have a long list of items (say, a few million items) in a mysql table, let's call it mytable and it has the field mytable.itemid. The items are given an order, and can be re=ordered by the user by drag and drop. If I add a field called mytable.order and just put numbers in them, it creates problems: what if I want to move an item between 2 other items? Then all the order fields have to be updated? That seems like a nightmare. Is there a (scalable) way to add order to a table that is different from just giving every item a number, order by that, and do loads of SQL queries everytime the order is changed?

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  • I am requesting ideas on manipulating output from an array and parse to something useful

    - by Cyber Demon
    First I am new to PS scripting. Please be gentle. This simple script I have written is ok. $Iplist = Get-Content ips.txt foreach ($ip in $Iplist) { .\psping -h -n 3 -w 0 $ip >> results.csv } Move-Item "C:\ping\results.csv" ("C:\ping\aftermath\{0:yyyyMMddhhmm}.csv" -f (get-date)) The Output is as follows, as an example (I used www.google.com): Pinging 74.125.225.48 with 32 bytes of data: 3 iterations (warmup 0) ping test: Reply from 74.125.225.48: 54.14ms Reply from 74.125.225.48: 54.85ms Reply from 74.125.225.48: 54.48ms Ping statistics for 74.125.225.48: Sent = 3, Received = 3, Lost = 0 (0% loss), Minimum = 54.14ms, Maximum = 54.85ms, Average = 54.49ms Latency Count 54.14 1 54.17 0 54.21 0 54.25 0 54.29 0 54.32 0 54.36 0 54.4 0 54.44 0 54.47 1 54.51 0 54.55 0 54.59 0 54.62 0 54.66 0 54.7 0 54.74 0 54.77 0 54.81 0 54.85 1 What I'm looking for is something to show me the following as an output. ServerIP Name TimeStamp Results AverageResponseTime in milli-seconds www.google.com 2014-08-14T16:09:59 Up 53 Can you guide me?

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  • Copying just the data from one Database to another

    - by monksy
    I'm not sure if this is the site for this question or not [if so put in the comment or vote to move it] How can I copy only the data from one database to another within the same server on SQL Server 2005? The two databases have the same schema but not the same data. I'm trying to get the data from one database to another. I am not able to restore from a snapshot [that screws over the security settings on the database]. I'm not able to use the import data wizard, because that is trying to copy over schema data as well.

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  • My company is a Rackspace Cloud client (provided to us for free) and I'm trying to find some way to set up version control

    - by Nick S.
    As the title says, my (small) business is provided a free Rackspace Cloud client account. We receive a decent amount of traffic but I haven't been able to put together a business case to move to our own server yet. However, we are developing some complex apps and I'm frustrated with not having the ability to even ssh into the remote server. Ultimately, I'd like to set up some sort of version control (at this point, I'll take anything, git or otherwise). I have control over databases, can FTP, set up cron jobs, and perform a few other basic functions. I can't think of any way to set up git or something similar without ssh access. A thought went through my mind that maybe some sort of PHP version control exists that I might be able to set up, but I haven't had any luck finding it yet. Do you guys have any ideas, thoughts, or advice?

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  • Path of the local directory

    - by Jayesh
    Hi, A rather simple question; how to find the path of the local directory in which my exe is placed? As-in I have an .exe and in the program I have to create a txt file in the directory where the exe is! [language - C#] So, if the exe is in C:/Temp and is started from there; my txt should be created in C:/Temp If the user wishes to move the exe to D:/Temp and runs from there; I should be able to create the txt file in D:/Temp I tried the Directory.GetCurrentDirectory() but that returns the directory of the execution of the program!

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  • Moving an item up and down in a WPF list box

    - by DommyCastles
    I have a list box with a bunch of values in it. I also have an UP button and a DOWN button. With these buttons, I would like to move the selected item in the list box up/down. I am having trouble doing this. Here is my code so far: private void btnDataUp_Click(object sender, RoutedEventArgs e) { int selectedIndex = listBoxDatasetValues.SelectedIndex; //get the selected item in the data list if (selectedIndex != -1 && selectedIndex != 0) //if the selected item is selected and not at the top of the list { //swap items here listBoxDatasetValues.SelectedIndex = selectedIndex - 1; //keep the item selected } } I do not know how to swap the values! Any help would be GREATLY appreciated!

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  • Loading jQuery Consistently in a .NET Web App

    - by Rick Strahl
    One thing that frequently comes up in discussions when using jQuery is how to best load the jQuery library (as well as other commonly used and updated libraries) in a Web application. Specifically the issue is the one of versioning and making sure that you can easily update and switch versions of script files with application wide settings in one place and having your script usage reflect those settings in the entire application on all pages that use the script. Although I use jQuery as an example here, the same concepts can be applied to any script library - for example in my Web libraries I use the same approach for jQuery.ui and my own internal jQuery support library. The concepts used here can be applied both in WebForms and MVC. Loading jQuery Properly From CDN Before we look at a generic way to load jQuery via some server logic, let me first point out my preferred way to embed jQuery into the page. I use the Google CDN to load jQuery and then use a fallback URL to handle the offline or no Internet connection scenario. Why use a CDN? CDN links tend to be loaded more quickly since they are very likely to be cached in user's browsers already as jQuery CDN is used by many, many sites on the Web. Using a CDN also removes load from your Web server and puts the load bearing on the CDN provider - in this case Google - rather than on your Web site. On the downside, CDN links gives the provider (Google, Microsoft) yet another way to track users through their Web usage. Here's how I use jQuery CDN plus a fallback link on my WebLog for example: <!DOCTYPE HTML> <html> <head> <script src="//ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.min.js"></script> <script> if (typeof (jQuery) == 'undefined') document.write(unescape("%3Cscript " + "src='/Weblog/wwSC.axd?r=Westwind.Web.Controls.Resources.jquery.js' %3E%3C/script%3E")); </script> <title>Rick Strahl's Web Log</title> ... </head>   You can see that the CDN is referenced first, followed by a small script block that checks to see whether jQuery was loaded (jQuery object exists). If it didn't load another script reference is added to the document dynamically pointing to a backup URL. In this case my backup URL points at a WebResource in my Westwind.Web  assembly, but the URL can also be local script like src="/scripts/jquery.min.js". Important: Use the proper Protocol/Scheme for  for CDN Urls [updated based on comments] If you're using a CDN to load an external script resource you should always make sure that the script is loaded with the same protocol as the parent page to avoid mixed content warnings by the browser. You don't want to load a script link to an http:// resource when you're on an https:// page. The easiest way to use this is by using a protocol relative URL: <script src="//ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.min.js"></script> which is an easy way to load resources from other domains. This URL syntax will automatically use the parent page's protocol (or more correctly scheme). As long as the remote domains support both http:// and https:// access this should work. BTW this also works in CSS (with some limitations) and links. BTW, I didn't know about this until it was pointed out in the comments. This is a very useful feature for many things - ah the benefits of my blog to myself :-) Version Numbers When you use a CDN you notice that you have to reference a specific version of jQuery. When using local files you may not have to do this as you can rename your private copy of jQuery.js, but for CDN the references are always versioned. The version number is of course very important to ensure you getting the version you have tested with, but it's also important to the provider because it ensures that cached content is always correct. If an existing file was updated the updates might take a very long time to get past the locally cached content and won't refresh properly. The version number ensures you get the right version and not some cached content that has been changed but not updated in your cache. On the other hand version numbers also mean that once you decide to use a new version of the script you now have to change all your script references in your pages. Depending on whether you use some sort of master/layout page or not this may or may not be easy in your application. Even if you do use master/layout pages, chances are that you probably have a few of them and at the very least all of those have to be updated for the scripts. If you use individual pages for all content this issue then spreads to all of your pages. Search and Replace in Files will do the trick, but it's still something that's easy to forget and worry about. Personaly I think it makes sense to have a single place where you can specify common script libraries that you want to load and more importantly which versions thereof and where they are loaded from. Loading Scripts via Server Code Script loading has always been important to me and as long as I can remember I've always built some custom script loading routines into my Web frameworks. WebForms makes this fairly easy because it has a reasonably useful script manager (ClientScriptManager and the ScriptManager) which allow injecting script into the page easily from anywhere in the Page cycle. What's nice about these components is that they allow scripts to be injected by controls so components can wrap up complex script/resource dependencies more easily without having to require long lists of CSS/Scripts/Image includes. In MVC or pure script driven applications like Razor WebPages  the process is more raw, requiring you to embed script references in the right place. But its also more immediate - it lets you know exactly which versions of scripts to use because you have to manually embed them. In WebForms with different controls loading resources this often can get confusing because it's quite possible to load multiple versions of the same script library into a page, the results of which are less than optimal… In this post I look a simple routine that embeds jQuery into the page based on a few application wide configuration settings. It returns only a string of the script tags that can be manually embedded into a Page template. It's a small function that merely a string of the script tags shown at the begging of this post along with some options on how that string is comprised. You'll be able to specify in one place which version loads and then all places where the help function is used will automatically reflect this selection. Options allow specification of the jQuery CDN Url, the fallback Url and where jQuery should be loaded from (script folder, Resource or CDN in my case). While this is specific to jQuery you can apply this to other resources as well. For example I use a similar approach with jQuery.ui as well using practically the same semantics. Providing Resources in ControlResources In my Westwind.Web Web utility library I have a class called ControlResources which is responsible for holding resource Urls, resource IDs and string contants that reference those resource IDs. The library also provides a few helper methods for loading common scriptscripts into a Web page. There are specific versions for WebForms which use the ClientScriptManager/ScriptManager and script link methods that can be used in any .NET technology that can embed an expression into the output template (or code for that matter). The ControlResources class contains mostly static content - references to resources mostly. But it also contains a few static properties that configure script loading: A Script LoadMode (CDN, Resource, or script url) A default CDN Url A fallback url They are  static properties in the ControlResources class: public class ControlResources { /// <summary> /// Determines what location jQuery is loaded from /// </summary> public static JQueryLoadModes jQueryLoadMode = JQueryLoadModes.ContentDeliveryNetwork; /// <summary> /// jQuery CDN Url on Google /// </summary> public static string jQueryCdnUrl = "//ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.min.js"; /// <summary> /// jQuery CDN Url on Google /// </summary> public static string jQueryUiCdnUrl = "//ajax.googleapis.com/ajax/libs/jqueryui/1.8.16/jquery-ui.min.js"; /// <summary> /// jQuery UI fallback Url if CDN is unavailable or WebResource is used /// Note: The file needs to exist and hold the minimized version of jQuery ui /// </summary> public static string jQueryUiLocalFallbackUrl = "~/scripts/jquery-ui.min.js"; } These static properties are fixed values that can be changed at application startup to reflect your preferences. Since they're static they are application wide settings and respected across the entire Web application running. It's best to set these default in Application_Init or similar startup code if you need to change them for your application: protected void Application_Start(object sender, EventArgs e) { // Force jQuery to be loaded off Google Content Network ControlResources.jQueryLoadMode = JQueryLoadModes.ContentDeliveryNetwork; // Allow overriding of the Cdn url ControlResources.jQueryCdnUrl = "http://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js"; // Route to our own internal handler App.OnApplicationStart(); } With these basic settings in place you can then embed expressions into a page easily. In WebForms use: <!DOCTYPE html> <html> <head runat="server"> <%= ControlResources.jQueryLink() %> <script src="scripts/ww.jquery.min.js"></script> </head> In Razor use: <!DOCTYPE html> <html> <head> @Html.Raw(ControlResources.jQueryLink()) <script src="scripts/ww.jquery.min.js"></script> </head> Note that in Razor you need to use @Html.Raw() to force the string NOT to escape. Razor by default escapes string results and this ensures that the HTML content is properly expanded as raw HTML text. Both the WebForms and Razor output produce: <!DOCTYPE html> <html> <head> <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js" type="text/javascript"></script> <script type="text/javascript"> if (typeof (jQuery) == 'undefined') document.write(unescape("%3Cscript src='/WestWindWebToolkitWeb/WebResource.axd?d=-b6oWzgbpGb8uTaHDrCMv59VSmGhilZP5_T_B8anpGx7X-PmW_1eu1KoHDvox-XHqA1EEb-Tl2YAP3bBeebGN65tv-7-yAimtG4ZnoWH633pExpJor8Qp1aKbk-KQWSoNfRC7rQJHXVP4tC0reYzVw2&t=634535391996872492' type='text/javascript'%3E%3C/script%3E"));</script> <script src="scripts/ww.jquery.min.js"></script> </head> which produces the desired effect for both CDN load and fallback URL. The implementation of jQueryLink is pretty basic of course: /// <summary> /// Inserts a script link to load jQuery into the page based on the jQueryLoadModes settings /// of this class. Default load is by CDN plus WebResource fallback /// </summary> /// <param name="url"> /// An optional explicit URL to load jQuery from. Url is resolved. /// When specified no fallback is applied /// </param> /// <returns>full script tag and fallback script for jQuery to load</returns> public static string jQueryLink(JQueryLoadModes jQueryLoadMode = JQueryLoadModes.Default, string url = null) { string jQueryUrl = string.Empty; string fallbackScript = string.Empty; if (jQueryLoadMode == JQueryLoadModes.Default) jQueryLoadMode = ControlResources.jQueryLoadMode; if (!string.IsNullOrEmpty(url)) jQueryUrl = WebUtils.ResolveUrl(url); else if (jQueryLoadMode == JQueryLoadModes.WebResource) { Page page = new Page(); jQueryUrl = page.ClientScript.GetWebResourceUrl(typeof(ControlResources), ControlResources.JQUERY_SCRIPT_RESOURCE); } else if (jQueryLoadMode == JQueryLoadModes.ContentDeliveryNetwork) { jQueryUrl = ControlResources.jQueryCdnUrl; if (!string.IsNullOrEmpty(jQueryCdnUrl)) { // check if jquery loaded - if it didn't we're not online and use WebResource fallbackScript = @"<script type=""text/javascript"">if (typeof(jQuery) == 'undefined') document.write(unescape(""%3Cscript src='{0}' type='text/javascript'%3E%3C/script%3E""));</script>"; fallbackScript = string.Format(fallbackScript, WebUtils.ResolveUrl(ControlResources.jQueryCdnFallbackUrl)); } } string output = "<script src=\"" + jQueryUrl + "\" type=\"text/javascript\"></script>"; // add in the CDN fallback script code if (!string.IsNullOrEmpty(fallbackScript)) output += "\r\n" + fallbackScript + "\r\n"; return output; } There's one dependency here on WebUtils.ResolveUrl() which resolves Urls without access to a Page/Control (another one of those features that should be in the runtime, not in the WebForms or MVC engine). You can see there's only a little bit of logic in this code that deals with potentially different load modes. I can load scripts from a Url, WebResources or - my preferred way - from CDN. Based on the static settings the scripts to embed are composed to be returned as simple string <script> tag(s). I find this extremely useful especially when I'm not connected to the internet so that I can quickly swap in a local jQuery resource instead of loading from CDN. While CDN loading with the fallback works it can be a bit slow as the CDN is probed first before the fallback kicks in. Switching quickly in one place makes this trivial. It also makes it very easy once a new version of jQuery rolls around to move up to the new version and ensure that all pages are using the new version immediately. I'm not trying to make this out as 'the' definite way to load your resources, but rather provide it here as a pointer so you can maybe apply your own logic to determine where scripts come from and how they load. You could even automate this some more by using configuration settings or reading the locations/preferences out of some sort of data/metadata store that can be dynamically updated instead via recompilation. FWIW, I use a very similar approach for loading jQuery UI and my own ww.jquery library - the same concept can be applied to any kind of script you might be loading from different locations. Hopefully some of you find this a useful addition to your toolset. Resources Google CDN for jQuery Full ControlResources Source Code ControlResource Documentation Westwind.Web NuGet This method is part of the Westwind.Web library of the West Wind Web Toolkit or you can grab the Web library from NuGet and add to your Visual Studio project. This package includes a host of Web related utilities and script support features. © Rick Strahl, West Wind Technologies, 2005-2011Posted in ASP.NET  jQuery   Tweet (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • Using PHP OCI8 with 32-bit PHP on Windows 64-bit

    - by christopher.jones
    The world migration from 32-bit to 64-bit operating systems is gaining pace. However I've seen a couple of customers having difficulty with the PHP OCI8 extension and Oracle DB on Windows 64-bit platforms. The errors vary depending how PHP is run. They may appear in the Apache or PHP log: Unable to load dynamic library 'C:\Program Files (x86)\PHP\ext\php_oci8_11g.dll' - %1 is not a valid Win32 application. or Warning oci_connect(): OCIEnvNlsCreate() failed. There is something wrong with your system - please check that PATH includes the directory with Oracle Instant Client libraries Other than IIS permission issues a common cause seems to be trying to use PHP with libraries from an Oracle 64-bit database on the same machine. There is currently no 64-bit version of PHP on http://php.net/ so there is a library mismatch. A solution is to install Oracle Instant Client 32-bit and make sure that PHP uses these libraries, while not interferring with the 64-bit database on the same machine. Warning: The following hacky steps come untested from a Linux user: Unzip Oracle Instant Client 32-bit and move it to C:\WINDOWS\SYSWOW64\INSTANTCLIENT_11_2. You may need to do this in a console with elevated permissions. Edit your PATH environment variable and insert C:\WINDOWS\SYSTEM32\INSTANTCLIENT_11_2 in the directory list before the entry for the Oracle Home library. Windows makes it so all 32-bit applications that reference C:\WINDOWS\SYSTEM32 actually see the contents of the C:\WINDOWS\SYSWOW64 directory. Your 64-bit database won't find an Instant Client in the real, physical C:\WINDOWS\SYSTEM32 directory and will continue to use the database libraries. Some of our Windows team are concerned about this hack and prefer a more "correct" solution that (i) doesn't require changing the Windows system directory (ii) doesn't add to the "memory" burden about what was configured on the system (iii) works when there are multiple database versions installed. The solution is to write a script which will set the 64-bit (or 32-bit) Oracle libraries in the path as needed before invoking the relevant bit-ness application. This does have a weakness when the application is started as a service. As a footnote: If you don't have a local database and simply need to have 32-bit and 64-bit Instant Client accessible at the same time, try the "symbolic" link approach covered in the hack in this OTN forum thread. Reminder warning: This blog post came untested from a Linux user.

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  • Visual Studio 2010 SP1 Beta supports IIS Express

    - by DigiMortal
    Visual Studio 2010 SP1 Beta and ASP.NET MVC 3 RC2 were both announced today. I made a little test on one of my web applications to see how Visual Studio 2010 works with IIS Express. In this posting I will show you how to make your ASP.NET MVC 3 application work with IIS Express. Installing new stuff You can install IIS Express using Web Platform Installer. It is not part of WebMatrix anymore and you can just install IIS Express without WebMatrix. NB! You have to install IIS Express using Web Platform installer because IIS Express is not installed by SP1. After installing Visual Studio 2010 SP1 Beta on my machine (it took a long-long-long time to install) I installed also ASP.NET MVC 3 RC2. If you have Async CTP installed on your machine you have to uninstall it to get ASP.NET MVC 3 RC2 installed and run without problems. Screenshot on right shows what kinf of horrors my old laptop had to survive to get all new stuff installer. Setting IIS Express as server for web application Now, when you right-click on some web project you should see new menu item in context menu – Use IIS Express…. If you click on it you are asked for confirmation and if you say Yes then your web application is reconfigured to use IIS Express. After configuration you will see dialog box like this. And you are done. You can run your application now. Running web application When you run your application it is run on IIS Express. You can see IIS Express icon on taskbar and when you click it you can open IIS Express settings. If you closed your application in browser you can open it again from IIS Express icon. Modifying IIS Express settings for web application You can modify IIS Express settings for your application. Just open your project properties and move to Web tab. IIS and IIS Express are using same settings. The difference is if you make check to Use IIS Express checkbox or not. Switching back to Visual Studio Development Server If you don’t want or you can’t use IIS Express for some reason you can easily switch back to Visual Studio Development Server. Just right-click on your web application project and select Use Visual Studio Development Server from context menu. Conclusion IIS Express is more independent than full version of IIS and it can be also installed and run on machines where are very strict rules (some corporate and academic environments by example). IIS Express was previously part of WebMatrix package but now it is separate product and Visual Studio 2010 has very nice support for it thanks to SP1. You can easily make your web applications use IIS Express and if you want to switch back to development server it is also very easy.

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  • Announcing the Release of Visual Studio 2013 and Great Improvements to ASP.NET and Entity Framework

    - by ScottGu
    Today we released VS 2013 and .NET 4.5.1. These releases include a ton of great improvements, and include some fantastic enhancements to ASP.NET and the Entity Framework.  You can download and start using them now. Below are details on a few of the great ASP.NET, Web Development, and Entity Framework improvements you can take advantage of with this release.  Please visit http://www.asp.net/vnext for additional release notes, documentation, and tutorials. One ASP.NET With the release of Visual Studio 2013, we have taken a step towards unifying the experience of using the different ASP.NET sub-frameworks (Web Forms, MVC, Web API, SignalR, etc), and you can now easily mix and match the different ASP.NET technologies you want to use within a single application. When you do a File-New Project with VS 2013 you’ll now see a single ASP.NET Project option: Selecting this project will bring up an additional dialog that allows you to start with a base project template, and then optionally add/remove the technologies you want to use in it.  For example, you could start with a Web Forms template and add Web API or Web Forms support for it, or create a MVC project and also enable Web Forms pages within it: This makes it easy for you to use any ASP.NET technology you want within your apps, and take advantage of any feature across the entire ASP.NET technology span. Richer Authentication Support The new “One ASP.NET” project dialog also includes a new Change Authentication button that, when pushed, enables you to easily change the authentication approach used by your applications – and makes it much easier to build secure applications that enable SSO from a variety of identity providers.  For example, when you start with the ASP.NET Web Forms or MVC templates you can easily add any of the following authentication options to the application: No Authentication Individual User Accounts (Single Sign-On support with FaceBook, Twitter, Google, and Microsoft ID – or Forms Auth with ASP.NET Membership) Organizational Accounts (Single Sign-On support with Windows Azure Active Directory ) Windows Authentication (Active Directory in an intranet application) The Windows Azure Active Directory support is particularly cool.  Last month we updated Windows Azure Active Directory so that developers can now easily create any number of Directories using it (for free and deployed within seconds).  It now takes only a few moments to enable single-sign-on support within your ASP.NET applications against these Windows Azure Active Directories.  Simply choose the “Organizational Accounts” radio button within the Change Authentication dialog and enter the name of your Windows Azure Active Directory to do this: This will automatically configure your ASP.NET application to use Windows Azure Active Directory and register the application with it.  Now when you run the app your users can easily and securely sign-in using their Active Directory credentials within it – regardless of where the application is hosted on the Internet. For more information about the new process for creating web projects, see Creating ASP.NET Web Projects in Visual Studio 2013. Responsive Project Templates with Bootstrap The new default project templates for ASP.NET Web Forms, MVC, Web API and SPA are built using Bootstrap. Bootstrap is an open source CSS framework that helps you build responsive websites which look great on different form factors such as mobile phones, tables and desktops. For example in a browser window the home page created by the MVC template looks like the following: When you resize the browser to a narrow window to see how it would like on a phone, you can notice how the contents gracefully wrap around and the horizontal top menu turns into an icon: When you click the menu-icon above it expands into a vertical menu – which enables a good navigation experience for small screen real-estate devices: We think Bootstrap will enable developers to build web applications that work even better on phones, tablets and other mobile devices – and enable you to easily build applications that can leverage the rich ecosystem of Bootstrap CSS templates already out there.  You can learn more about Bootstrap here. Visual Studio Web Tooling Improvements Visual Studio 2013 includes a new, much richer, HTML editor for Razor files and HTML files in web applications. The new HTML editor provides a single unified schema based on HTML5. It has automatic brace completion, jQuery UI and AngularJS attribute IntelliSense, attribute IntelliSense Grouping, and other great improvements. For example, typing “ng-“ on an HTML element will show the intellisense for AngularJS: This support for AngularJS, Knockout.js, Handlebars and other SPA technologies in this release of ASP.NET and VS 2013 makes it even easier to build rich client web applications: The screen shot below demonstrates how the HTML editor can also now inspect your page at design-time to determine all of the CSS classes that are available. In this case, the auto-completion list contains classes from Bootstrap’s CSS file. No more guessing at which Bootstrap element names you need to use: Visual Studio 2013 also comes with built-in support for both CoffeeScript and LESS editing support. The LESS editor comes with all the cool features from the CSS editor and has specific Intellisense for variables and mixins across all the LESS documents in the @import chain. Browser Link – SignalR channel between browser and Visual Studio The new Browser Link feature in VS 2013 lets you run your app within multiple browsers on your dev machine, connect them to Visual Studio, and simultaneously refresh all of them just by clicking a button in the toolbar. You can connect multiple browsers (including IE, FireFox, Chrome) to your development site, including mobile emulators, and click refresh to refresh all the browsers all at the same time.  This makes it much easier to easily develop/test against multiple browsers in parallel. Browser Link also exposes an API to enable developers to write Browser Link extensions.  By enabling developers to take advantage of the Browser Link API, it becomes possible to create very advanced scenarios that crosses boundaries between Visual Studio and any browser that’s connected to it. Web Essentials takes advantage of the API to create an integrated experience between Visual Studio and the browser’s developer tools, remote controlling mobile emulators and a lot more. You will see us take advantage of this support even more to enable really cool scenarios going forward. ASP.NET Scaffolding ASP.NET Scaffolding is a new code generation framework for ASP.NET Web applications. It makes it easy to add boilerplate code to your project that interacts with a data model. In previous versions of Visual Studio, scaffolding was limited to ASP.NET MVC projects. With Visual Studio 2013, you can now use scaffolding for any ASP.NET project, including Web Forms. When using scaffolding, we ensure that all required dependencies are automatically installed for you in the project. For example, if you start with an ASP.NET Web Forms project and then use scaffolding to add a Web API Controller, the required NuGet packages and references to enable Web API are added to your project automatically.  To do this, just choose the Add->New Scaffold Item context menu: Support for scaffolding async controllers uses the new async features from Entity Framework 6. ASP.NET Identity ASP.NET Identity is a new membership system for ASP.NET applications that we are introducing with this release. ASP.NET Identity makes it easy to integrate user-specific profile data with application data. ASP.NET Identity also allows you to choose the persistence model for user profiles in your application. You can store the data in a SQL Server database or another data store, including NoSQL data stores such as Windows Azure Storage Tables. ASP.NET Identity also supports Claims-based authentication, where the user’s identity is represented as a set of claims from a trusted issuer. Users can login by creating an account on the website using username and password, or they can login using social identity providers (such as Microsoft Account, Twitter, Facebook, Google) or using organizational accounts through Windows Azure Active Directory or Active Directory Federation Services (ADFS). To learn more about how to use ASP.NET Identity visit http://www.asp.net/identity.  ASP.NET Web API 2 ASP.NET Web API 2 has a bunch of great improvements including: Attribute routing ASP.NET Web API now supports attribute routing, thanks to a contribution by Tim McCall, the author of http://attributerouting.net. With attribute routing you can specify your Web API routes by annotating your actions and controllers like this: OAuth 2.0 support The Web API and Single Page Application project templates now support authorization using OAuth 2.0. OAuth 2.0 is a framework for authorizing client access to protected resources. It works for a variety of clients including browsers and mobile devices. OData Improvements ASP.NET Web API also now provides support for OData endpoints and enables support for both ATOM and JSON-light formats. With OData you get support for rich query semantics, paging, $metadata, CRUD operations, and custom actions over any data source. Below are some of the specific enhancements in ASP.NET Web API 2 OData. Support for $select, $expand, $batch, and $value Improved extensibility Type-less support Reuse an existing model OWIN Integration ASP.NET Web API now fully supports OWIN and can be run on any OWIN capable host. With OWIN integration, you can self-host Web API in your own process alongside other OWIN middleware, such as SignalR. For more information, see Use OWIN to Self-Host ASP.NET Web API. More Web API Improvements In addition to the features above there have been a host of other features in ASP.NET Web API, including CORS support Authentication Filters Filter Overrides Improved Unit Testability Portable ASP.NET Web API Client To learn more go to http://www.asp.net/web-api/ ASP.NET SignalR 2 ASP.NET SignalR is library for ASP.NET developers that dramatically simplifies the process of adding real-time web functionality to your applications. Real-time web functionality is the ability to have server-side code push content to connected clients instantly as it becomes available. SignalR 2.0 introduces a ton of great improvements. We’ve added support for Cross-Origin Resource Sharing (CORS) to SignalR 2.0. iOS and Android support for SignalR have also been added using the MonoTouch and MonoDroid components from the Xamarin library (for more information on how to use these additions, see the article Using Xamarin Components from the SignalR wiki). We’ve also added support for the Portable .NET Client in SignalR 2.0 and created a new self-hosting package. This change makes the setup process for SignalR much more consistent between web-hosted and self-hosted SignalR applications. To learn more go to http://www.asp.net/signalr. ASP.NET MVC 5 The ASP.NET MVC project templates integrate seamlessly with the new One ASP.NET experience and enable you to integrate all of the above ASP.NET Web API, SignalR and Identity improvements. You can also customize your MVC project and configure authentication using the One ASP.NET project creation wizard. The MVC templates have also been updated to use ASP.NET Identity and Bootstrap as well. An introductory tutorial to ASP.NET MVC 5 can be found at Getting Started with ASP.NET MVC 5. This release of ASP.NET MVC also supports several nice new MVC-specific features including: Authentication filters: These filters allow you to specify authentication logic per-action, per-controller or globally for all controllers. Attribute Routing: Attribute Routing allows you to define your routes on actions or controllers. To learn more go to http://www.asp.net/mvc Entity Framework 6 Improvements Visual Studio 2013 ships with Entity Framework 6, which bring a lot of great new features to the data access space: Async and Task<T> Support EF6’s new Async Query and Save support enables you to perform asynchronous data access and take advantage of the Task<T> support introduced in .NET 4.5 within data access scenarios.  This allows you to free up threads that might otherwise by blocked on data access requests, and enable them to be used to process other requests whilst you wait for the database engine to process operations. When the database server responds the thread will be re-queued within your ASP.NET application and execution will continue.  This enables you to easily write significantly more scalable server code. Here is an example ASP.NET WebAPI action that makes use of the new EF6 async query methods: Interception and Logging Interception and SQL logging allows you to view – or even change – every command that is sent to the database by Entity Framework. This includes a simple, human readable log – which is great for debugging – as well as some lower level building blocks that give you access to the command and results. Here is an example of wiring up the simple log to Debug in the constructor of an MVC controller: Custom Code-First Conventions The new Custom Code-First Conventions enable bulk configuration of a Code First model – reducing the amount of code you need to write and maintain. Conventions are great when your domain classes don’t match the Code First conventions. For example, the following convention configures all properties that are called ‘Key’ to be the primary key of the entity they belong to. This is different than the default Code First convention that expects Id or <type name>Id. Connection Resiliency The new Connection Resiliency feature in EF6 enables you to register an execution strategy to handle – and potentially retry – failed database operations. This is especially useful when deploying to cloud environments where dropped connections become more common as you traverse load balancers and distributed networks. EF6 includes a built-in execution strategy for SQL Azure that knows about retryable exception types and has some sensible – but overridable – defaults for the number of retries and time between retries when errors occur. Registering it is simple using the new Code-Based Configuration support: These are just some of the new features in EF6. You can visit the release notes section of the Entity Framework site for a complete list of new features. Microsoft OWIN Components Open Web Interface for .NET (OWIN) defines an open abstraction between .NET web servers and web applications, and the ASP.NET “Katana” project brings this abstraction to ASP.NET. OWIN decouples the web application from the server, making web applications host-agnostic. For example, you can host an OWIN-based web application in IIS or self-host it in a custom process. For more information about OWIN and Katana, see What's new in OWIN and Katana. Summary Today’s Visual Studio 2013, ASP.NET and Entity Framework release delivers some fantastic new features that streamline your web development lifecycle. These feature span from server framework to data access to tooling to client-side HTML development.  They also integrate some great open-source technology and contributions from our developer community. Download and start using them today! Scott P.S. In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu

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  • Inheritance Mapping Strategies with Entity Framework Code First CTP5: Part 3 – Table per Concrete Type (TPC) and Choosing Strategy Guidelines

    - by mortezam
    This is the third (and last) post in a series that explains different approaches to map an inheritance hierarchy with EF Code First. I've described these strategies in previous posts: Part 1 – Table per Hierarchy (TPH) Part 2 – Table per Type (TPT)In today’s blog post I am going to discuss Table per Concrete Type (TPC) which completes the inheritance mapping strategies supported by EF Code First. At the end of this post I will provide some guidelines to choose an inheritance strategy mainly based on what we've learned in this series. TPC and Entity Framework in the Past Table per Concrete type is somehow the simplest approach suggested, yet using TPC with EF is one of those concepts that has not been covered very well so far and I've seen in some resources that it was even discouraged. The reason for that is just because Entity Data Model Designer in VS2010 doesn't support TPC (even though the EF runtime does). That basically means if you are following EF's Database-First or Model-First approaches then configuring TPC requires manually writing XML in the EDMX file which is not considered to be a fun practice. Well, no more. You'll see that with Code First, creating TPC is perfectly possible with fluent API just like other strategies and you don't need to avoid TPC due to the lack of designer support as you would probably do in other EF approaches. Table per Concrete Type (TPC)In Table per Concrete type (aka Table per Concrete class) we use exactly one table for each (nonabstract) class. All properties of a class, including inherited properties, can be mapped to columns of this table, as shown in the following figure: As you can see, the SQL schema is not aware of the inheritance; effectively, we’ve mapped two unrelated tables to a more expressive class structure. If the base class was concrete, then an additional table would be needed to hold instances of that class. I have to emphasize that there is no relationship between the database tables, except for the fact that they share some similar columns. TPC Implementation in Code First Just like the TPT implementation, we need to specify a separate table for each of the subclasses. We also need to tell Code First that we want all of the inherited properties to be mapped as part of this table. In CTP5, there is a new helper method on EntityMappingConfiguration class called MapInheritedProperties that exactly does this for us. Here is the complete object model as well as the fluent API to create a TPC mapping: public abstract class BillingDetail {     public int BillingDetailId { get; set; }     public string Owner { get; set; }     public string Number { get; set; } }          public class BankAccount : BillingDetail {     public string BankName { get; set; }     public string Swift { get; set; } }          public class CreditCard : BillingDetail {     public int CardType { get; set; }     public string ExpiryMonth { get; set; }     public string ExpiryYear { get; set; } }      public class InheritanceMappingContext : DbContext {     public DbSet<BillingDetail> BillingDetails { get; set; }              protected override void OnModelCreating(ModelBuilder modelBuilder)     {         modelBuilder.Entity<BankAccount>().Map(m =>         {             m.MapInheritedProperties();             m.ToTable("BankAccounts");         });         modelBuilder.Entity<CreditCard>().Map(m =>         {             m.MapInheritedProperties();             m.ToTable("CreditCards");         });                 } } The Importance of EntityMappingConfiguration ClassAs a side note, it worth mentioning that EntityMappingConfiguration class turns out to be a key type for inheritance mapping in Code First. Here is an snapshot of this class: namespace System.Data.Entity.ModelConfiguration.Configuration.Mapping {     public class EntityMappingConfiguration<TEntityType> where TEntityType : class     {         public ValueConditionConfiguration Requires(string discriminator);         public void ToTable(string tableName);         public void MapInheritedProperties();     } } As you have seen so far, we used its Requires method to customize TPH. We also used its ToTable method to create a TPT and now we are using its MapInheritedProperties along with ToTable method to create our TPC mapping. TPC Configuration is Not Done Yet!We are not quite done with our TPC configuration and there is more into this story even though the fluent API we saw perfectly created a TPC mapping for us in the database. To see why, let's start working with our object model. For example, the following code creates two new objects of BankAccount and CreditCard types and tries to add them to the database: using (var context = new InheritanceMappingContext()) {     BankAccount bankAccount = new BankAccount();     CreditCard creditCard = new CreditCard() { CardType = 1 };                      context.BillingDetails.Add(bankAccount);     context.BillingDetails.Add(creditCard);     context.SaveChanges(); } Running this code throws an InvalidOperationException with this message: The changes to the database were committed successfully, but an error occurred while updating the object context. The ObjectContext might be in an inconsistent state. Inner exception message: AcceptChanges cannot continue because the object's key values conflict with another object in the ObjectStateManager. Make sure that the key values are unique before calling AcceptChanges. The reason we got this exception is because DbContext.SaveChanges() internally invokes SaveChanges method of its internal ObjectContext. ObjectContext's SaveChanges method on its turn by default calls AcceptAllChanges after it has performed the database modifications. AcceptAllChanges method merely iterates over all entries in ObjectStateManager and invokes AcceptChanges on each of them. Since the entities are in Added state, AcceptChanges method replaces their temporary EntityKey with a regular EntityKey based on the primary key values (i.e. BillingDetailId) that come back from the database and that's where the problem occurs since both the entities have been assigned the same value for their primary key by the database (i.e. on both BillingDetailId = 1) and the problem is that ObjectStateManager cannot track objects of the same type (i.e. BillingDetail) with the same EntityKey value hence it throws. If you take a closer look at the TPC's SQL schema above, you'll see why the database generated the same values for the primary keys: the BillingDetailId column in both BankAccounts and CreditCards table has been marked as identity. How to Solve The Identity Problem in TPC As you saw, using SQL Server’s int identity columns doesn't work very well together with TPC since there will be duplicate entity keys when inserting in subclasses tables with all having the same identity seed. Therefore, to solve this, either a spread seed (where each table has its own initial seed value) will be needed, or a mechanism other than SQL Server’s int identity should be used. Some other RDBMSes have other mechanisms allowing a sequence (identity) to be shared by multiple tables, and something similar can be achieved with GUID keys in SQL Server. While using GUID keys, or int identity keys with different starting seeds will solve the problem but yet another solution would be to completely switch off identity on the primary key property. As a result, we need to take the responsibility of providing unique keys when inserting records to the database. We will go with this solution since it works regardless of which database engine is used. Switching Off Identity in Code First We can switch off identity simply by placing DatabaseGenerated attribute on the primary key property and pass DatabaseGenerationOption.None to its constructor. DatabaseGenerated attribute is a new data annotation which has been added to System.ComponentModel.DataAnnotations namespace in CTP5: public abstract class BillingDetail {     [DatabaseGenerated(DatabaseGenerationOption.None)]     public int BillingDetailId { get; set; }     public string Owner { get; set; }     public string Number { get; set; } } As always, we can achieve the same result by using fluent API, if you prefer that: modelBuilder.Entity<BillingDetail>()             .Property(p => p.BillingDetailId)             .HasDatabaseGenerationOption(DatabaseGenerationOption.None); Working With The Object Model Our TPC mapping is ready and we can try adding new records to the database. But, like I said, now we need to take care of providing unique keys when creating new objects: using (var context = new InheritanceMappingContext()) {     BankAccount bankAccount = new BankAccount()      {          BillingDetailId = 1                          };     CreditCard creditCard = new CreditCard()      {          BillingDetailId = 2,         CardType = 1     };                      context.BillingDetails.Add(bankAccount);     context.BillingDetails.Add(creditCard);     context.SaveChanges(); } Polymorphic Associations with TPC is Problematic The main problem with this approach is that it doesn’t support Polymorphic Associations very well. After all, in the database, associations are represented as foreign key relationships and in TPC, the subclasses are all mapped to different tables so a polymorphic association to their base class (abstract BillingDetail in our example) cannot be represented as a simple foreign key relationship. For example, consider the the domain model we introduced here where User has a polymorphic association with BillingDetail. This would be problematic in our TPC Schema, because if User has a many-to-one relationship with BillingDetail, the Users table would need a single foreign key column, which would have to refer both concrete subclass tables. This isn’t possible with regular foreign key constraints. Schema Evolution with TPC is Complex A further conceptual problem with this mapping strategy is that several different columns, of different tables, share exactly the same semantics. This makes schema evolution more complex. For example, a change to a base class property results in changes to multiple columns. It also makes it much more difficult to implement database integrity constraints that apply to all subclasses. Generated SQLLet's examine SQL output for polymorphic queries in TPC mapping. For example, consider this polymorphic query for all BillingDetails and the resulting SQL statements that being executed in the database: var query = from b in context.BillingDetails select b; Just like the SQL query generated by TPT mapping, the CASE statements that you see in the beginning of the query is merely to ensure columns that are irrelevant for a particular row have NULL values in the returning flattened table. (e.g. BankName for a row that represents a CreditCard type). TPC's SQL Queries are Union Based As you can see in the above screenshot, the first SELECT uses a FROM-clause subquery (which is selected with a red rectangle) to retrieve all instances of BillingDetails from all concrete class tables. The tables are combined with a UNION operator, and a literal (in this case, 0 and 1) is inserted into the intermediate result; (look at the lines highlighted in yellow.) EF reads this to instantiate the correct class given the data from a particular row. A union requires that the queries that are combined, project over the same columns; hence, EF has to pad and fill up nonexistent columns with NULL. This query will really perform well since here we can let the database optimizer find the best execution plan to combine rows from several tables. There is also no Joins involved so it has a better performance than the SQL queries generated by TPT where a Join is required between the base and subclasses tables. Choosing Strategy GuidelinesBefore we get into this discussion, I want to emphasize that there is no one single "best strategy fits all scenarios" exists. As you saw, each of the approaches have their own advantages and drawbacks. Here are some rules of thumb to identify the best strategy in a particular scenario: If you don’t require polymorphic associations or queries, lean toward TPC—in other words, if you never or rarely query for BillingDetails and you have no class that has an association to BillingDetail base class. I recommend TPC (only) for the top level of your class hierarchy, where polymorphism isn’t usually required, and when modification of the base class in the future is unlikely. If you do require polymorphic associations or queries, and subclasses declare relatively few properties (particularly if the main difference between subclasses is in their behavior), lean toward TPH. Your goal is to minimize the number of nullable columns and to convince yourself (and your DBA) that a denormalized schema won’t create problems in the long run. If you do require polymorphic associations or queries, and subclasses declare many properties (subclasses differ mainly by the data they hold), lean toward TPT. Or, depending on the width and depth of your inheritance hierarchy and the possible cost of joins versus unions, use TPC. By default, choose TPH only for simple problems. For more complex cases (or when you’re overruled by a data modeler insisting on the importance of nullability constraints and normalization), you should consider the TPT strategy. But at that point, ask yourself whether it may not be better to remodel inheritance as delegation in the object model (delegation is a way of making composition as powerful for reuse as inheritance). Complex inheritance is often best avoided for all sorts of reasons unrelated to persistence or ORM. EF acts as a buffer between the domain and relational models, but that doesn’t mean you can ignore persistence concerns when designing your classes. SummaryIn this series, we focused on one of the main structural aspect of the object/relational paradigm mismatch which is inheritance and discussed how EF solve this problem as an ORM solution. We learned about the three well-known inheritance mapping strategies and their implementations in EF Code First. Hopefully it gives you a better insight about the mapping of inheritance hierarchies as well as choosing the best strategy for your particular scenario. Happy New Year and Happy Code-Firsting! References ADO.NET team blog Java Persistence with Hibernate book a { color: #5A99FF; } a:visited { color: #5A99FF; } .title { padding-bottom: 5px; font-family: Segoe UI; font-size: 11pt; font-weight: bold; padding-top: 15px; } .code, .typeName { font-family: consolas; } .typeName { color: #2b91af; } .padTop5 { padding-top: 5px; } .padTop10 { padding-top: 10px; } .exception { background-color: #f0f0f0; font-style: italic; padding-bottom: 5px; padding-left: 5px; padding-top: 5px; padding-right: 5px; }

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