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Articles indexed Tuesday April 27 2010

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  • What is the "Apple" key and what key is it that is depicted as part of an upper case X?

    - by Marnix A. van Ammers
    I read in some answers about using the "Apple" + "Space bar" keys. Which is the "Apple" key? Also, I see in my Mac OS X Safari menu bar that to open the download window I can use a 3 key combination. The last of the 3 keys are the Command key (depicted with a clover leaf symbol) and the 'L' key. The first key is the one I don't see anywhere. It is depicted by a symbol that looks to me like an upper case 'X' with most of the forward slash part removed. What key is that? OK, just discovered by trial and error that it must be a symbol for the "option" key. What is that symbol called and why is it not on the keyboard?

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  • Apache configuration to access directory

    - by Felipe Hummel
    I'm on Ubuntu 9.10. My web application is in a directory on my /home/me/app . I want to configure Apache in such a way that I can access my app through a directory. For example: People can access my machine through domain.com. What I would like to do is access my web application (located at /home/me/app) through a directory, using something like: domain.com/myapp. How can I set up the apache configuration for this kind of behavior? Of course, I do not want to move all my application to /var/www/myapp. Thanks

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  • Do I still have to implement a singleton class by hand in .net, even when using .Net4.0?

    - by Hamish Grubijan
    Once the singleton pattern is understood, writing subsequent singleton classes in C# is a brainless exercise. I would hope that the framework would help you by providing an interface or a base class to do that. Here is how I envision it: public sealed class Schablone : ISingleton<Schablone> { // Stuff forced by the interface goes here // Extra logic goes here } Does what I am looking for exist? Is there some syntactic sugar for constructing a singleton class - whether with an interface, a class attribute, etc.? Can one write a useful and bullet-proof ISingleton themselves? Care to try? Thanks!

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  • Invoke Maven-Module build from intellij

    - by Roman
    Hi All I was wondering if someone knows a way to invoke a specific maven module build from IntelliJ that will also build ( or use already compiled classes ) from depended modules. So for instance if I would like to build the module "Model" in the picture and only it , it seems reasonable for me to click the package step on it. But what is actually does it invokes the mvn package step inside this specific module rather than "mvn -am -pl module-name" from the root module , which also builds all the dependencies. So is there something that I just don't know ?

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  • Compressing three individual jpeg pics containing temporal redundancy?

    - by michael
    I am interfacing and embedded device with a camera module that returns a single jpeg compressed frame each time I trigger it. I would like to take three successive shots (approx 1 frame per 1/4 second) and further compress the images into a single file. The assumption here is that there is a lot of temporal redundancy, therefore lots of room for more compression across the three frames (compared to sending three separate jpeg images). I will be implementing the solution on an embedded device in C without any libraries and no OS. The camera will be taking pics in an area with very little movement (no visitors or screens in the background, maybe a tree with swaying branches), so I think my assumption about redundancy is pretty solid. When the file is finally viewed on a pc/mac, I don't mind having to write something to extract the three frames (so it can be a nonstandard cluge) So I guess the actual question is: What is the best way to compress these three images together given the fact that they are already in JPEG format (it is a possibly to convert back to a raw image, but if i dont have too...)

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  • Can I connect to SQL from JavaScript MVC?

    - by user54197
    I am populating a list of names that will be added to my Sql Database. In this simple case, how do I send the information to SQL server without my page being refreshed? <script type="text/javascript"> function addNewRow() { $('#displayPropertyTable tr:last').after('<tr><td style="font-size:smaller;" class="name"></td><td style="font-size:smaller;" class="address"></td></tr>'); var $tr = $('#displayPropertyTable tr:last'); var propertyCondition = $('#txtPropAddress').val(); if (propertyCondition != "") { $tr.find('.name').text($('#txtPropName').val()); $tr.find('.address').text($('#txtPropAddress').val()); } } </script> ... <table id="displayPropertyTable" width= "100%"> <tr> <td style="font-size:smaller;" class="name"></td> <td style="font-size:smaller;" class="address"></td> </tr> </table> ... <table> <tr> <td><b>Name</b></td> <td colspan="2"><input id="txtPropName" type="text" /></td> </tr> <tr> <td><b>Address</b></td> <td colspan="2"><input id="txtPropAddress" type="text" /></td> </tr> </table> ... <button onclick="addNewRow();">Add</button>

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  • jquery toggle did not work properly...

    - by pradeep
    function advanced_search() { $("#advanced_link").toggle( function(){ $('#advanced_link').text('Hide - Advanced Search'); $('.advanced_search').show(); }, function(){ $('#advanced_link').text('Show - Advanced Search'); $('.advanced_search').hide(); }); } this code worked for me..but when i tried to use the css property like function advanced_search() { $("#advanced_link").toggle( function(){ $('#advanced_link').text('Hide - Advanced Search'); $('.advanced_search').css('display','inline'); }, function(){ $('#advanced_link').text('Show - Advanced Search'); $('.advanced_search').css('display','none'); }); } it did not work...is there any thing wrong in second code...??

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  • php security holes Proof-Of-Concept [closed]

    - by Flavius
    Hi Could you show me a Proof-Of-Concept for all of these: XSS, CSRF, SQL injection with both the source code and the attack steps for each? Other attack vectors are welcome. The most complete answer gets accepted. The configuration is a fairly standard one, as of PHP 5.3.2, core settings: allow_call_time_pass_reference => Off => Off allow_url_fopen => On => On allow_url_include => Off => Off always_populate_raw_post_data => Off => Off arg_separator.input => & => & arg_separator.output => & => & asp_tags => Off => Off auto_append_file => no value => no value auto_globals_jit => On => On auto_prepend_file => no value => no value browscap => no value => no value default_charset => no value => no value default_mimetype => text/html => text/html define_syslog_variables => Off => Off disable_classes => no value => no value disable_functions => no value => no value display_errors => STDOUT => STDOUT display_startup_errors => On => On doc_root => no value => no value docref_ext => no value => no value docref_root => no value => no value enable_dl => Off => Off error_append_string => no value => no value error_log => syslog => syslog error_prepend_string => no value => no value error_reporting => 32767 => 32767 exit_on_timeout => Off => Off expose_php => On => On extension_dir => /usr/lib/php/modules/ => /usr/lib/php/modules/ file_uploads => On => On html_errors => Off => Off ignore_repeated_errors => Off => Off ignore_repeated_source => Off => Off ignore_user_abort => Off => Off implicit_flush => On => On include_path => .:/usr/share/pear => .:/usr/share/pear log_errors => On => On log_errors_max_len => 1024 => 1024 magic_quotes_gpc => Off => Off magic_quotes_runtime => Off => Off magic_quotes_sybase => Off => Off mail.add_x_header => On => On mail.force_extra_parameters => no value => no value mail.log => no value => no value max_execution_time => 0 => 0 max_file_uploads => 20 => 20 max_input_nesting_level => 64 => 64 max_input_time => -1 => -1 memory_limit => 128M => 128M open_basedir => no value => no value output_buffering => 0 => 0 output_handler => no value => no value post_max_size => 8M => 8M precision => 14 => 14 realpath_cache_size => 16K => 16K realpath_cache_ttl => 120 => 120 register_argc_argv => On => On register_globals => Off => Off register_long_arrays => Off => Off report_memleaks => On => On report_zend_debug => Off => Off request_order => GP => GP safe_mode => Off => Off safe_mode_exec_dir => no value => no value safe_mode_gid => Off => Off safe_mode_include_dir => no value => no value sendmail_from => no value => no value sendmail_path => /usr/sbin/sendmail -t -i => /usr/sbin/sendmail -t -i serialize_precision => 100 => 100 short_open_tag => Off => Off SMTP => localhost => localhost smtp_port => 25 => 25 sql.safe_mode => Off => Off track_errors => Off => Off unserialize_callback_func => no value => no value upload_max_filesize => 2M => 2M upload_tmp_dir => no value => no value user_dir => no value => no value user_ini.cache_ttl => 300 => 300 user_ini.filename => .user.ini => .user.ini variables_order => GPCS => GPCS xmlrpc_error_number => 0 => 0 xmlrpc_errors => Off => Off y2k_compliance => On => On zend.enable_gc => On => On

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  • IE won't load PDF in a window created with window.open

    - by Dean
    Here's the problem, which only occurs in Internet Explorer (IE). I have a page that has links to several different types of files. Links from these files execute a Javascript function that opens a new window and loads the specific file. This works great, unless the file I need to open in the new window is a PDF in which case the window is blank, even though the URL is in the address field. Refreshing that window using F5 doesn't help. However, if I put the cursor in the address field and press <enter> the PDF loads right up. This problem only occurs in IE. I have seen it in IE 7 and 8 and am using Adobe Acrobat Reader 9. In Firefox (PC and Mac) everything works perfectly. In Chrome (Mac), the PDF is downloaded. In Safari (Mac) it works. In Opera (Mac) it prompts me to open or save. Basically, everything probably works fine, except for IE. I have searched for similar problems and have seen some posts where it was suggested to adjust some of the Internet Options on IE. I have tried this but it doesn't help, and the problem wasn't exactly the same anyway. Here's the Javascript function I use to open the new window. function newwin(url,w,h) { win = window.open(url,"temp","width="+w+",height="+h+",menubar=yes,toolbar=yes,location=yes,status=yes,scrollbars=auto,resizable=yes"); win.focus(); } You can see that I pass in the URL as well as the height, h, and width, w, of the window. I've used a function like this for years and as far as I know have never had a problem. I call the newwin() function using this. <a href="javascript:newwin('/path/document.pdf',400,300)">document.pdf</a> (Yes, I know there are other, better ways than using inline JS, and I've even tried some of them because I've run out of things to try, but nothing works.) So, if anyone has an idea as to what might be causing this problem, I'd love to hear it.

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  • Should I use `import os.path` or `import os`?

    - by Denilson Sá
    According to the official documentation, os.path is a module. Thus, what is the preferred way of importing it? # Should I always import it explicitly? import os.path Or... # Is importing os enough? import os Please DON'T answer "importing os works for me". I know, it works for me too right now. What I want to know is any official recommendation about this issue. So, if you answer this question, please post your references.

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  • Regex file extension filter

    - by NickLarsen
    I am trying to create a regex that will take all files that do not have a list of extensions. In particular, I am trying to filter out filenames that end in .csv I have browsed around for an hour and been unable to figure this out. I am using .NET Regex.

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  • How to deploy a report on a report server installed on a Windows7 machine?

    - by Sergio
    I need to deploy a report using Reporting services but i'm getting this error, using visual studio to deploy the report The permissions granted to user 'Domain\user' are insufficient for performing this operation Right now i'm the administrator of the machine, so why i'm getting i don't hace enough permissions? Note: The scenario is the following: Developing and deploying on a windows7 The report server is in the same machine. In conclusion, running all local. In spanish: Necesito hacer un deploy de un reporte en Reporting Services. Cuando corro el visual studio obtengo el siguiente error. Los permisos otorgados al usuario son insuficientes para realizar esta operación Actualmente soy el administrador de la máquina, entonces no entiendo porque aparece el error que no tengo suficientes permisos. Notas: Este es el escenario Desarrollando y haciendo el deploy en una máquina con windows7. El Report Server y el Visual Studio están en la misma máquina. En conclusión, todo lo corro localmente. Actualmente soy el administrador de la máquina, entonces no entiendo porque aparece el error que no tengo suficientes permisos.

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  • I am using a constructor for my array but why is it saying i need a return type?

    - by JB
    using System; using System.IO; using System.Data; using System.Text; using System.Drawing; using System.Data.OleDb; using System.Collections; using System.ComponentModel; using System.Windows.Forms; using System.Drawing.Printing; using System.Collections.Generic; namespace Eagle_Eye_Class_Finder { public class GetSchedule { public class IDnumber { public string Name { get; set; } public string ID { get; set; } public string year { get; set; } public string class1 { get; set; } public string class2 { get; set; } public string class3 { get; set; } public string class4 { get; set; } IDnumber[] IDnumbers = new IDnumber[3]; public GetSchedule() //here i get an error saying method must have a return type??? { IDnumbers[0] = new IDnumber() { Name = "Joshua Banks",ID = "900456317", year = "Senior", class1 = "TEET 4090", class2 = "TEET 3020", class3 = "TEET 3090", class4 = "TEET 4290" }; IDnumbers[1] = new IDnumber() { Name = "Sean Ward", ID = "900456318", year = "Junior", class1 = "ENGNR 4090", class2 = "ENGNR 3020", class3 = "ENGNR 3090", class4 = "ENGNR 4290" }; IDnumbers[2] = new IDnumber() { Name = "Terrell Johnson",ID = "900456319",year = "Sophomore", class1 = "BUS 4090", class2 = "BUS 3020", class3 = "BUS 3090", class4 = "BUS 4290" }; } static void ProcessNumber(IDnumber myNum) { StringBuilder myData = new StringBuilder(); myData.AppendLine(IDnumber.Name); myData.AppendLine(": "); myData.AppendLine(IDnumber.ID); myData.AppendLine(IDnumber.year); myData.AppendLine(IDnumber.class1); myData.AppendLine(IDnumber.class2); myData.AppendLine(IDnumber.class3); myData.AppendLine(IDnumber.class4); MessageBox.Show(myData); } public string GetDataFromNumber(string ID) { foreach (IDnumber idCandidateMatch in IDnumbers) { if (IDCandidateMatch.ID == ID) { StringBuilder myData = new StringBuilder(); myData.AppendLine(IDnumber.Name); myData.AppendLine(": "); myData.AppendLine(IDnumber.ID); myData.AppendLine(IDnumber.year); myData.AppendLine(IDnumber.class1); myData.AppendLine(IDnumber.class2); myData.AppendLine(IDnumber.class3); myData.AppendLine(IDnumber.class4); return myData; } } return ""; } } } }

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  • Howto specify format of Restlet-response in browser?

    - by martin
    Hello everybody, i've started to introduce myself into REST. I use as REST-framework Restlet. I have defined a resource with methods for the GET with several response formats like @Get("xml") @Get("json") I now want to test my defined response-formats with my browser, but I don't know which parameter I have to specify in my URL to get the format. Something like: http://localhost:8182/members?type=xml I've tried some param-names, but I couldn't find the right param-name. I know that there must be such a parameter, because I've seen it already in an URL, but i forgot the name and couldn't find it in the net. How is the name of this parameter when using restlet? I would be pleased, if somebody can help me, thanks, Martin

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  • problem with clear: right;

    - by toomanyairmiles
    Hi Everyone, I'm having a problem with this page http://www.gwynfryncottages.com/news.php The .blog-footer div needs to clear on the right to correct for the height of the pictures introducing clear:right; causes the huge gap to appear on the page in FF and IE. I'm at a loss, I've tried numerous ideas to get around the problem and at this point i've been staring at it too long to see the problem clearly. Can anyone help me out. Thanks in advance.

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  • asp.net MVC binding specific model results in error for post request

    - by Tomh
    Hi I'm having the following two actions defined in my controller [Authorize] [HttpGet] public ActionResult Edit() { ViewData.Model = HttpContext.User.Identity; return View(); } [Authorize] [HttpPost] public ActionResult Edit(User model) { return View(); } However if I post my editted data to the second action I get the following error: Server Error in '/' Application. An item with the same key has already been added. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.ArgumentException: An item with the same key has already been added. Source Error: An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below. I tried several things like renaming parameters and removing editable fields, but it seems the model type is the problem, what could be wrong? Stack Trace: [ArgumentException: An item with the same key has already been added.] System.ThrowHelper.ThrowArgumentException(ExceptionResource resource) +51 System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add) +7464444 System.Linq.Enumerable.ToDictionary(IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector, IEqualityComparer`1 comparer) +270 System.Linq.Enumerable.ToDictionary(IEnumerable`1 source, Func`2 keySelector, IEqualityComparer`1 comparer) +102 System.Web.Mvc.ModelBindingContext.get_PropertyMetadata() +157 System.Web.Mvc.DefaultModelBinder.BindProperty(ControllerContext controllerContext, ModelBindingContext bindingContext, PropertyDescriptor propertyDescriptor) +158 System.Web.Mvc.DefaultModelBinder.BindProperties(ControllerContext controllerContext, ModelBindingContext bindingContext) +90 System.Web.Mvc.DefaultModelBinder.BindComplexElementalModel(ControllerContext controllerContext, ModelBindingContext bindingContext, Object model) +50 System.Web.Mvc.DefaultModelBinder.BindComplexModel(ControllerContext controllerContext, ModelBindingContext bindingContext) +1048 System.Web.Mvc.DefaultModelBinder.BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext) +280 System.Web.Mvc.ControllerActionInvoker.GetParameterValue(ControllerContext controllerContext, ParameterDescriptor parameterDescriptor) +257 System.Web.Mvc.ControllerActionInvoker.GetParameterValues(ControllerContext controllerContext, ActionDescriptor actionDescriptor) +109 System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +314 System.Web.Mvc.Controller.ExecuteCore() +105 System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext) +39 System.Web.Mvc.ControllerBase.System.Web.Mvc.IController.Execute(RequestContext requestContext) +7 System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__4() +34 System.Web.Mvc.Async.<>c__DisplayClass1.<MakeVoidDelegate>b__0() +21 System.Web.Mvc.Async.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _) +12 System.Web.Mvc.Async.WrappedAsyncResult`1.End() +59 System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +44 System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +7 System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +8679150 System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155

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  • Catching multiple keystrokes simultaneously in Cocoa

    - by Vinod Kumar
    I have used 4 NSButtons and assigned them to the 4 arrow keys separately to move in four different directions. Now I want to use two keystrokes, left arrow and up arrow together simultaneously, for north east movement, how can I do it? I am only able to use one keystroke at a time , I need to catch two key strokes simultaneously, I need it for my game project.

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  • Entity Framework v1 &ndash; tips and Tricks Part 3

    - by Rohit Gupta
    General Tips on Entity Framework v1 & Linq to Entities: ToTraceString() If you need to know the underlying SQL that the EF generates for a Linq To Entities query, then use the ToTraceString() method of the ObjectQuery class. (or use LINQPAD) Note that you need to cast the LINQToEntities query to ObjectQuery before calling TotraceString() as follows: 1: string efSQL = ((ObjectQuery)from c in ctx.Contact 2: where c.Address.Any(a => a.CountryRegion == "US") 3: select c.ContactID).ToTraceString(); ================================================================================ MARS or MultipleActiveResultSet When you create a EDM Model (EDMX file) from the database using Visual Studio, it generates a connection string with the same name as the name of the EntityContainer in CSDL. In the ConnectionString so generated it sets the MultipleActiveResultSet attribute to true by default. So if you are running the following query then it streams multiple readers over the same connection: 1: using (BAEntities context = new BAEntities()) 2: { 3: var cons = 4: from con in context.Contacts 5: where con.FirstName == "Jose" 6: select con; 7: foreach (var c in cons) 8: { 9: if (c.AddDate < new System.DateTime(2007, 1, 1)) 10: { 11: c.Addresses.Load(); 12: } 13: } 14: } ================================================================================= Explicitly opening and closing EntityConnection When you call ToList() or foreach on a LINQToEntities query the EF automatically closes the connection after all the records from the query have been consumed. Thus if you need to run many LINQToEntities queries over the same connection then explicitly open and close the connection as follows: 1: using (BAEntities context = new BAEntities()) 2: { 3: context.Connection.Open(); 4: var cons = from con in context.Contacts where con.FirstName == "Jose" 5: select con; 6: var conList = cons.ToList(); 7: var allCustomers = from con in context.Contacts.OfType<Customer>() 8: select con; 9: var allcustList = allCustomers.ToList(); 10: context.Connection.Close(); 11: } ====================================================================== Dispose ObjectContext only if required After you retrieve entities using the ObjectContext and you are not explicitly disposing the ObjectContext then insure that your code does consume all the records from the LinqToEntities query by calling .ToList() or foreach statement, otherwise the the database connection will remain open and will be closed by the garbage collector when it gets to dispose the ObjectContext. Secondly if you are making updates to the entities retrieved using LinqToEntities then insure that you dont inadverdently dispose of the ObjectContext after the entities are retrieved and before calling .SaveChanges() since you need the SAME ObjectContext to keep track of changes made to the Entities (by using ObjectStateEntry objects). So if you do need to explicitly dispose of the ObjectContext do so only after calling SaveChanges() and only if you dont need to change track the entities retrieved any further. ======================================================================= SQL InjectionAttacks under control with EFv1 LinqToEntities and LinqToSQL queries are parameterized before they are sent to the DB hence they are not vulnerable to SQL Injection attacks. EntitySQL may be slightly vulnerable to attacks since it does not use parameterized queries. However since the EntitySQL demands that the query be valid Entity SQL syntax and valid native SQL syntax at the same time. So the only way one can do a SQLInjection Attack is by knowing the SSDL of the EDM Model and be able to write the correct EntitySQL (note one cannot append regular SQL since then the query wont be a valid EntitySQL syntax) and append it to a parameter. ====================================================================== Improving Performance You can convert the EntitySets and AssociationSets in a EDM Model into precompiled Views using the edmgen utility. for e.g. the Customer Entity can be converted into a precompiled view using edmgen and all LinqToEntities query against the contaxt.Customer EntitySet will use the precompiled View instead of the EntitySet itself (the same being true for relationships (EntityReference & EntityCollections of a Entity)). The advantage being that when using precompiled views the performance will be much better. The syntax for generating precompiled views for a existing EF project is : edmgen /mode:ViewGeneration /inssdl:BAModel.ssdl /incsdl:BAModel.csdl /inmsl:BAModel.msl /p:Chap14.csproj Note that this will only generate precompiled views for EntitySets and Associations and not for existing LinqToEntities queries in the project.(for that use CompiledQuery.Compile<>) Secondly if you have a LinqToEntities query that you need to run multiple times, then one should precompile the query using CompiledQuery.Compile method. The CompiledQuery.Compile<> method accepts a lamda expression as a parameter, which denotes the LinqToEntities query  that you need to precompile. The following is a example of a lamda that we can pass into the CompiledQuery.Compile() method 1: Expression<Func<BAEntities, string, IQueryable<Customer>>> expr = (BAEntities ctx1, string loc) => 2: from c in ctx1.Contacts.OfType<Customer>() 3: where c.Reservations.Any(r => r.Trip.Destination.DestinationName == loc) 4: select c; Then we call the Compile Query as follows: 1: var query = CompiledQuery.Compile<BAEntities, string, IQueryable<Customer>>(expr); 2:  3: using (BAEntities ctx = new BAEntities()) 4: { 5: var loc = "Malta"; 6: IQueryable<Customer> custs = query.Invoke(ctx, loc); 7: var custlist = custs.ToList(); 8: foreach (var item in custlist) 9: { 10: Console.WriteLine(item.FullName); 11: } 12: } Note that if you created a ObjectQuery or a Enitity SQL query instead of the LINQToEntities query, you dont need precompilation for e.g. 1: An Example of EntitySQL query : 2: string esql = "SELECT VALUE c from Contacts AS c where c is of(BAGA.Customer) and c.LastName = 'Gupta'"; 3: ObjectQuery<Customer> custs = CreateQuery<Customer>(esql); 1: An Example of ObjectQuery built using ObjectBuilder methods: 2: from c in Contacts.OfType<Customer>().Where("it.LastName == 'Gupta'") 3: select c This is since the Query plan is cached and thus the performance improves a bit, however since the ObjectQuery or EntitySQL query still needs to materialize the results into Entities hence it will take the same amount of performance hit as with LinqToEntities. However note that not ALL EntitySQL based or QueryBuilder based ObjectQuery plans are cached. So if you are in doubt always create a LinqToEntities compiled query and use that instead ============================================================ GetObjectStateEntry Versus GetObjectByKey We can get to the Entity being referenced by the ObjectStateEntry via its Entity property and there are helper methods in the ObjectStateManager (osm.TryGetObjectStateEntry) to get the ObjectStateEntry for a entity (for which we know the EntityKey). Similarly The ObjectContext has helper methods to get an Entity i.e. TryGetObjectByKey(). TryGetObjectByKey() uses GetObjectStateEntry method under the covers to find the object, however One important difference between these 2 methods is that TryGetObjectByKey queries the database if it is unable to find the object in the context, whereas TryGetObjectStateEntry only looks in the context for existing entries. It will not make a trip to the database ============================================================= POCO objects with EFv1: To create POCO objects that can be used with EFv1. We need to implement 3 key interfaces: IEntityWithKey IEntityWithRelationships IEntityWithChangeTracker Implementing IEntityWithKey is not mandatory, but if you dont then we need to explicitly provide values for the EntityKey for various functions (for e.g. the functions needed to implement IEntityWithChangeTracker and IEntityWithRelationships). Implementation of IEntityWithKey involves exposing a property named EntityKey which returns a EntityKey object. Implementation of IEntityWithChangeTracker involves implementing a method named SetChangeTracker since there can be multiple changetrackers (Object Contexts) existing in memory at the same time. 1: public void SetChangeTracker(IEntityChangeTracker changeTracker) 2: { 3: _changeTracker = changeTracker; 4: } Additionally each property in the POCO object needs to notify the changetracker (objContext) that it is updating itself by calling the EntityMemberChanged and EntityMemberChanging methods on the changeTracker. for e.g.: 1: public EntityKey EntityKey 2: { 3: get { return _entityKey; } 4: set 5: { 6: if (_changeTracker != null) 7: { 8: _changeTracker.EntityMemberChanging("EntityKey"); 9: _entityKey = value; 10: _changeTracker.EntityMemberChanged("EntityKey"); 11: } 12: else 13: _entityKey = value; 14: } 15: } 16: ===================== Custom Property ==================================== 17:  18: [EdmScalarPropertyAttribute(IsNullable = false)] 19: public System.DateTime OrderDate 20: { 21: get { return _orderDate; } 22: set 23: { 24: if (_changeTracker != null) 25: { 26: _changeTracker.EntityMemberChanging("OrderDate"); 27: _orderDate = value; 28: _changeTracker.EntityMemberChanged("OrderDate"); 29: } 30: else 31: _orderDate = value; 32: } 33: } Finally you also need to create the EntityState property as follows: 1: public EntityState EntityState 2: { 3: get { return _changeTracker.EntityState; } 4: } The IEntityWithRelationships involves creating a property that returns RelationshipManager object: 1: public RelationshipManager RelationshipManager 2: { 3: get 4: { 5: if (_relManager == null) 6: _relManager = RelationshipManager.Create(this); 7: return _relManager; 8: } 9: } ============================================================ Tip : ProviderManifestToken – change EDMX File to use SQL 2008 instead of SQL 2005 To use with SQL Server 2008, edit the EDMX file (the raw XML) changing the ProviderManifestToken in the SSDL attributes from "2005" to "2008" ============================================================= With EFv1 we cannot use Structs to replace a anonymous Type while doing projections in a LINQ to Entities query. While the same is supported with LINQToSQL, it is not with LinqToEntities. For e.g. the following is not supported with LinqToEntities since only parameterless constructors and initializers are supported in LINQ to Entities. (the same works with LINQToSQL) 1: public struct CompanyInfo 2: { 3: public int ID { get; set; } 4: public string Name { get; set; } 5: } 6: var companies = (from c in dc.Companies 7: where c.CompanyIcon == null 8: select new CompanyInfo { Name = c.CompanyName, ID = c.CompanyId }).ToList(); ;

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