Search Results

Search found 27142 results on 1086 pages for 'control structure'.

Page 867/1086 | < Previous Page | 863 864 865 866 867 868 869 870 871 872 873 874  | Next Page >

• Regular expression to match HTML table row ( <tr> ) NOT containing a specific value

  - by user1821136

  I'm using Notepad++ to clean up a long and messy HTML table. I'm trying to use regular expressions even if I'm a total noob. :) I need to remove all the table rows that doesn't contain a specific value (may I call that substring?). After having all the file contents unwrapped, I've been able to use the following regular expression to select, one by one, every table row with all its contents: <tr>.+?</tr> How can I improve the regular expression in order to select and replace only table rows containing, somewhere inside a part of them, that defined substring? I don't know if this does matter but the structure of every table row is the following (I've put there every HTML tag, the dots stand for standard content/values) <tr> <td> ... </td> <td> ... </td> <td> <a sfref="..." href="...">!! SUBSTRING I HAVE TO MATCH HERE !!</a> </td> <td> <img /> </td> <td> ... </td> <td> ... </td> <td> ... </td> <td> ... </td> </tr> Thanks in advance for your help!

  Read the article

• Generating URLs when not using an integer as an id?

  - by Synthesezia

  So I'm building a blog engine which has /articles/then-the-article-permalink as it's URL structure. I need to have prev and next links which will jump to the next article by pub_date, my code looks like this: In my articles#show @article = Article.find_by_permalink(params[:id]) @prev_article = Article.find(:first, :conditions => [ "pub_date < ?", @article.pub_date]) @next_picture = Article.find(:first, :conditions => [ "pub_date > ?", @article.pub_date]) And in my show.html.erb <%= link_to "Next", article_path(@next_article) %> <%= link_to 'Prev', article_path(@prev_article) %> In my articles model I have this: def to_param self.permalink end The specific error message I get is: article_url failed to generate from {:action=>"show", :controller=>"articles", :id=>nil}, expected: {:action=>"show", :controller=>"articles"}, diff: {:id=>nil} Without the prev and next everything is working fine but I'm out of ideas as to why this isn't working. Anyone want to helo?

  Read the article

• Advice on whether to use native C++ DLL or not: PINVOKE & Marshaling ?

  - by Bob

  What's the best way to do this....? I have some Native C++ code that uses a lot of Win32 calls together with byte buffers (allocated using HeapAlloc). I'd like to extend the code and make a C# GUI...and maybe later use a basic Win32 GUI (for use where there is no .Net and limited MFC support). (A) I could just re-write the code in C# and use multiple PINVOKEs....but even with the PINVOKES in a separate class, the code looks messy with all the marshaling. I'm also re-writing a lot of code. (B) I could create a native C++ DLL and use PINVOKE to marshal in the native data structures. I'm assuming I can include the native C++ DLL/LIB in a project using C#? (C) Create a mixed mode DLL (Native C++ class plus managed ref class). I'm assuming that this would make it easier to use the managed ref class in C#......but is this the case? Will the managed class handle all the marshaling? Can I use this mixed mode DLL on a platform with no .Net (i.e. still access the native C++ unmanaged component) or do I limit myself to .Net only platforms. One thing that bothers me about each of these options is all the marshalling. Is it better to create a managed data structure (array, string etc.) and pass that to the native C++ class, or, the other way around? Any ideas on what would be considered best practice...?

  Read the article

• Mongodb - how to deserialze when a property has an Interface return type

  - by Mark Kelly

  I'm attempting to avoid introducing any dependencies between my Data layer and client code that makes use of this layer, but am running into some problems when attempting to do this with Mongo (using the MongoRepository) MongoRepository shows examples where you create Types that reflect your data structure, and inherit Entity where required. Eg. [CollectionName("track")] public class Track : Entity { public string name { get; set; } public string hash { get; set; } public Artist artist { get; set; } public List<Publish> published {get; set;} public List<Occurence> occurence {get; set;} } In order to make use of these in my client code, I'd like to replace the Mongo-specific types with Interfaces, e.g: [CollectionName("track")] public class Track : Entity, ITrackEntity { public string name { get; set; } public string hash { get; set; } public IArtistEntity artist { get; set; } public List<IPublishEntity> published {get; set;} public List<IOccurenceEntity> occurence {get; set;} } However, the Mongo driver doesn't know how to treat these interfaces, and I understandably get the following error: An error occurred while deserializing the artist property of class sf.data.mongodb.entities.Track: No serializer found for type sf.data.IArtistEntity. --- MongoDB.Bson.BsonSerializationException: No serializer found for type sf.data.IArtistEntity. Does anyone have any suggestions about how I should approach this?

  Read the article

• Assign C++ instance method to a global-function-pointer ?

  - by umanga

  Greetings, My project structure is as follows: \- base (C static library) callbacks.h callbacks.c paint_node.c . . * libBase.a \-app (C++ application) main.cpp In C library 'base' , I have declared global-function-pointer as: in singleheader file callbacks.h #ifndef CALLBACKS_H_ #define CALLBACKS_H_ extern void (*putPixelCallBack)(); extern void (*putImageCallBack)(); #endif /* CALLBACKS_H_ */ in single C file they are initialized as callbacks.c #include "callbacks.h" void (*putPixelCallBack)(); void (*putImageCallBack)(); Other C files access this callback-functions as: paint_node.c #include "callbacks.h" void paint_node(node *node,int index){ //Call callbackfunction . . putPixelCallBack(node->x,node->y,index); } I compile these C files and generate a static library 'libBase.a' Then in C++ application, I want to assign C++ instance method to this global function-pointer: I did something like follows : in Sacm.cpp file #include "Sacm.h" extern void (*putPixelCallBack)(); extern void (*putImageCallBack)(); void Sacm::doDetection() { putPixelCallBack=(void(*)())&paintPixel; //call somefunctions in 'libBase' C library } void Sacm::paintPixel(int x,int y,int index) { qpainter.begin(this); qpainter.drawPoint(x,y); qpainter.end(); } But when compiling it gives the error: sacmtest.cpp: In member function ‘void Sacm::doDetection()’: sacmtest.cpp:113: error: ISO C++ forbids taking the address of an unqualified or parenthesized non-static member function to form a pointer to member function. Say ‘&Sacm::paintPixel’ sacmtest.cpp:113: error: converting from ‘void (Sacm::)(int, int, int)’ to ‘void ()()’ Any tips?

  Read the article

• Git + GitHub + Heroku

  - by Haseeb Khan

  Hi All, I am new to the world of Git, GitHub and Heroku. So far, I am enjoying this paradigm but coming from a background with SVN, things seems a bit complicated to me in the world of Git. I am facing a problem for which I am looking for a solution. Scenario: I have setup a new private project on GitHub. I forked the private project and now I have the following structure in my branch: /project /apps /my-apps /my-app-1 .... /my-app-2 .... /your-apps /your-app-1 .... /your-app-2 .... /plugins .... I can commit the code in my Fork on GitHub from my machine in any of the folders I want. Later on, these would be pulled into the master repository by the admin of the project. For every individual application in the apps folder, I have setup an app on Heroku which is a Git Repo in itself where I push my changes when I am done with the user stories from my local machine. In short, every app in the apps folder is a Rails App hosted on Heroku. Problem: What I want is that when I push my changes into Heroku, they can be committed into my project fork on GitHub as well, so, it also has the latest code all the time. The issue I see is that the code on Heroku is a Git Repo while the folders which I have on GitHub are part of a Repo. So far, what I have researched is that there is something known as Submodule in the Git World which can come to the rescue, however, I have not been able to find some newbie instructions. Can someone in the community be kind enough to share thoughts and help me to identify the solution of this problem? Thanks in advance. Regards, Haseeb Khan haseeb [AT] tkxel.com TkXel

  Read the article

• How do you make life easier for yourself when developing a really large database

  - by Hannes de Jager

  I am busy developing 2 web based systems with MySql databases and the amount of tables/views/stored routines is really becoming a lot and it is more and more challenging to handle the complexity. Now in programming languages we have namespacing e.g. Java packages, C++ namespaces to partition the software, grouping it together to make things more understandable. Databases on the other hand have more of a flat structure (MySql at least) e.g. tables and stored procedures are on the same level. So one have to be more creative, creating naming conventions, perhaps use more than one database or using tools to visualize things. What methods do you use to ease the pain? To be effective while developing your databases? To not get lost in a sea of tables and fields and stored procs? Feel free to mention tools you use also, but try to restrict it to open source and preferably Linux solutions if thats OK. b.t.w How many tables would a database have to be considered large in terms of design?

  Read the article

• OptimisticLockException in inner transaction ruins outer transaction

  - by Pace

  I have the following code (OLE = OptimisticLockException)... public void outer() { try { middle() } catch (OLE) { updateEntities(); outer(); } } @Transactional public void middle() { try { inner() } catch (OLE) { updateEntities(); middle(); } @Transactional public void inner() { //Do DB operation } inner() is called by other non-transactional methods which is why both middle() and inner() are transactional. As you can see, I deal with OLEs by updating the entities and retrying the operation. The problem I'm having is that when I designed things this way I was assuming that the only time one could get an OLE was when a transaction closed. This is apparently not the case as the call to inner() is throwing an OLE even when the stack is outer()->middle()->inner(). Now, middle() is properly handling the OLE and the retry succeeds but when it comes time to close the transaction it has been marked rollbackOnly by Spring. When the middle() method call finally returns the closing aspect throws an exception because it can't commit a transaction marked rollbackOnly. I'm uncertain what to do here. I can't clear the rollbackOnly state. I don't want to force create a transaction on every call to inner because that kills my performance. Am I missing something or can anyone see a way I can structure this differently? EDIT: To clarify what I'm asking, let me explain my main question. Is it possible to catch and handle OLE if you are inside of an @Transactional method? FYI: The transaction manager is a JpaTransactionManager and the JPA provider is Hibernate.

  Read the article

• ASP.NET - Accessing copied content

  - by James Kolpack

  I have a class library project which contains some content files configured with the "Copy if newer" copy build action. This results in the files being copied to a folder under ...\bin\ for every project in the solution. In this same solution, I've got a ASP.NET web project (which is MVC, by the way). In the library I have a static constructor load the files into data structures accessible by the web project. Previously I've been including the content as an embedded resource. I now need to be able to replace them without recompiling. I want to access the data in three different contexts: Unit testing the library assembly Debugging the web application Hosting the site in IIS For unit testing, Environment.CurrentDirectory points to a path containing the copied content. When debugging however, it points to C:\Program Files\Microsoft Visual Studio 9.0\Common7\IDE. I've also looked at Assembly.GetExecutingAssembly().Location which points to C:\Windows\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\root\c44f9da4\9238ccc\assembly\dl3\eb4c23b4\9bd39460_f7d4ca01\. What I need is to the physical location of the webroot \bin folder, but since I'm in a static constructor in the library project, I don't have access to a Request.PhysicalApplicationPath. Is there some other environment variable or structure where I can always find my "Copy if newer" files?

  Read the article

• Trusted Folder/Drive Picker in the Browser

  - by kylepfritz

  I'd like to write a Folder/Drive picker the runs in the browser and allows a user to select files to upload to a webservice. The primary usage would be selecting folders or a whole CD and uploading them to the web with their directory structure in tact. I'm imagining something akin to Jumploader but which automatically enumerates external drives and CDs. I remember a version of Facebook's picture uploader that could do this sort of enumeration and was java-based but it has since been replaced by a much slicker plugin-based architecture. Because the application needs to run at very high trust, I think I'm limited to old-school java applets. Is there another alternative? I'm hesitant to start down the plugin route because of the necessity of writing one for both IE and Mozilla at a minimum. Are there good places to get started there? On the applet front, I built a clunky prototype to demonstrate that I can enumerate devices and list files. It runs fine in the applet viewer but I don't think I have the security settings configured correctly for it to run in the browser at full trust. Currently I don't get any drives back when I run it in the browser. Applet Prototype: public class Loader extends javax.swing.JApplet { ... private void EnumerateDrives(java.awt.event.ActionEvent evt) { File[] roots = File.listRoots(); StringBuilder b = new StringBuilder(); for (File root : roots) { b.append(root.getAbsolutePath() + ", "); } jLabel.setText(b.toString()); } } Embed Html: <p>Loader:</p> <script src="http://www.java.com/js/deployJava.js" type="text/javascript" ></script> <script> var attributes = {code:'org.exampl.Loader.Loader.class', archive:'Loader/dist/Loader.jar', width:600, height:400} ; var parameters = {}; deployJava.runApplet(attributes, parameters, '1.6');

  Read the article

• passing data from a servlet to javascript code in an Ajax application ?

  - by A.S al-shammari

  I have a simple jsp/servlet application and I want to add AJAX feature to this app. I use JQuery , but it doesn't matter what javascript framework I use. This is my code: <script type="text/javascript"> function callbackFunction(data){ $('#content').html(data); } $('document').ready(function(){ $('#x').click(function() { $.post('/ajax_2/servlet',callbackFunction) }); }); </script> <body> <a href="#" id="x">Increase it</a> <div id="content"></div> </body> </html> Servlet HttpSession session = request.getSession(); Integer myInteger = (Integer)session.getAttribute("myInteger"); if(myInteger == null) myInteger = new Integer(0); else myInteger = new Integer(myInteger+1); session.setAttribute("myInteger", myInteger); response.getWriter().println(myInteger); The Question: I use out.print to transfer data from a servlet to javascript code (ajax code) , but If I have a complex structure such as Vector of Object or something like this , what is the best way to transfer the data? what about an XML file , JSON ? Is there any special jsp/servlets library to transfer data from a servlet to ajax application ? How can I parse this data in callbackFunction ?

  Read the article

• Seperation of business logic

  - by bruno

  Dear all, When I was optimizing my architecture of our applications in our website, I came to a problem that I don't know the best solution for. Now at the moment we have a small dll based on this structure: Database <-> DAL <-> BLL the Dal uses Business Objects to pass to the BLL that will pass it to the applications that uses this dll. Only the BLL is public so any application that includes this dll, can see the bll. In the beginning, this was a good solution for our company. But when we are adding more and more applications on that Dll, the bigger the Bll is getting. Now we dont want that some applications can see Bll-logic from other applications. Now I don't know what the best solution is for that. The first thing I thought was, move and seperate the bll to other dll's which i can include in my application. But then must the Dal be public, so the other dll's can get the data... and that I seems like a good solution. My other soluition, is just to seperate the bll in different namespaces, and just include only the namespaces you need in the applications. But in this solution, you can get directly access to other bll's if you want. So i'm asking for your oppinions. Thx, Bruno

  Read the article

• KnockoutJS - creating object doesn't work

  - by Kiwanax

  I'm doing a navigation list with menus and submenus. I have the following structure: function Menu(navigation) { this.NavigationUrl = ko.observable(navigation.NavigationUrl); this.NavigationTitle = ko.observable(navigation.NavigationTitle); this.NavigationDescription = ko.observable(navigation.NavigationDescription); var mappedChildren = ko.utils.arrayMap(navigation.Children, function (child) { return new Menu(child); }); this.Children = ko.observableArray(mappedChildren); } function DashboardViewModel() { var self = this; self.LoggedUser = ko.observable(""); self.Navigations = ko.observableArray([]); $.get('/Home/DashboardDependencies', {}, function (result) { self.LoggedUser(result.LoggedUser); var mappedNavigations = ko.utils.arrayMap(result.Navigations, function (item) { var menu = new Menu(item); // When I alert item, the result appears properly: // { "NavigationTitle": "blah", "NavigationDescription": "bleh" [...] } alert(JSON.stringify(item)); // But when I alert the new menu object, the result doesn't appear: // Just: "{}" alert(JSON.stringify(menu)); return menu; }); self.Navigations = mappedNavigations; }); } ko.applyBindings(new DashboardViewModel()); So, check it out. When I try to alert the item variable, the result appears properly. When I try to alert the new Menu object, the result just show {}. Why this' happening? Thank you all for the help!

  Read the article

• Archiver Securing SQLite Data without using Encryption on iPhone

  - by Redrocks

  I'm developing an iphone app that uses Core Data with a SQLite data store and lots of images in the resource bundle. I want a "simple" way to obfuscate the file structure of the SQLite database and the image files to prevent the casual hacker/unscrupulous developer from gaining access to them. When the app is deployed, the database file and image files would be obfuscated. Upon launching the app it would read in and un-obfuscate the database file, write the un-obfuscated version to the users "tmp" directory for use by core data, and read/un-obfuscate image files as needed. I'd like to apply a simple algorithm to the files that would somehow scramble/manipulate the file data so that the sqlite database data isn't discernible when the db is opened in a text editor and so that neither is recognized by other applications (SQLite Manager, Photoshop, etc.) It seems, from the information I've read, that I could use NSFileManager, NSKeyedArchiver, and NSData to accomplish this but I'm not sure how to proceed. Been developing software for many years but I'm new to everything CocoaTouch, Mac and iPhone. Also never had to secure/encrypt my data so this is new. Any thoughts, suggestions, or links to solutions are appreciated.

  Read the article

• How to get the second sub element of every element in a list in R

  - by PaulHurleyuk

  I know I've come across this problem before, but I'm having a bit of a mental block at the moment. and as I can't find it on SO, I'll post it here so I can find it next time. I have a dataframe that contains a field representing an ID label. This label has two parts, an alpha prefix and a numeric suffix. I want to split it apart and create two new fields with these values in. structure(list(lab = c("N00", "N01", "N02", "B00", "B01", "B02", "Z21", "BA01", "NA03")), .Names = "lab", row.names = c(NA, -9L ), class = "data.frame") df$pre<-strsplit(df$lab, "[0-9]+") df$suf<-strsplit(df$lab, "[A-Z]+") Which gives lab pre suf 1 N00 N , 00 2 N01 N , 01 3 N02 N , 02 4 B00 B , 00 5 B01 B , 01 6 B02 B , 02 7 Z21 Z , 21 8 BA01 BA , 01 9 NA03 NA , 03 So, the first strsplit works fine, but the second gives a list, each having two elements, an empty string and the result I want, and stuffs them both into the dataframe column. How can I select the second sub-element from each element of the list ? (or, is there a better way to do this) Thanks Paul.

  Read the article

• How are two-dimensional arrays formatted in memory?

  - by Chris Cooper

  In C, I know I can dynamically allocate a two-dimensional array on the heap using the following code: int** someNumbers = malloc(arrayRows*sizeof(int*)); for (i = 0; i < arrayRows; i++) { someNumbers[i] = malloc(arrayColumns*sizeof(int)); } Clearly, this actually creates a one-dimensional array of pointers to a bunch of separate one-dimensional arrays of integers, and "The System" can figure you what I mean when I ask for: someNumbers[4][2]; But when I statically declare a 2D array, as in the following line...: int someNumbers[ARRAY_ROWS][ARRAY_COLUMNS]; ...does a similar structure get created on the stack, or is it of another form completely? (i.e. is it a 1D array of pointers? If not, what is it, and how do references to it get figured out?) Also, when I said, "The System," what is actually responsible for figuring that out? The kernel? Or does the C compiler sort it out while compiling?

  Read the article

• How does one implement storage/retrieval of smart-search/mailbox features?

  - by humble_coder

  Hi All, I have a question regarding implementation of smart-search features. For example, consider something like "smart mailboxes" in various email applications. Let's assume you have your data (emails) stored in a database and, depending on the field for which the query will be created, you present different options to the end user. At the moment let's assume the Subject, Verb, Object approach… For instance, say you have the following: SUBJECTs: message, to_address, from_address, subject, date_received VERBs: contains, does_not_contain, is_equal_to, greater_than, less_than OBJECTs: ??????? Now, in case it isn't clear, I want a table structure (although I'm not opposed to an external XMLesque file of some sort) to store (and later retrieve/present) my criteria for smart searches/mailboxes for later use. As an example, using SVO I could easily store then reconstruct a query for "date between two dates" -- simply use "date greater than" AND "date less than". However, what if, in the same smart search, I wanted a "between" OR'ed with another criterion? You can see that it might get out of hand -- not necessarily in the query creation (as that is rather simplistic), but in the option presentation and storage mechanism. Perhaps I need to think more on a more granular level. Perhaps I need to simply allow the user to select AND or OR for each entry independently instead of making it an ALL OR NOTHING type smart search (i.e. instead of MATCH ALL or MATCH ANY, I need to simply allow them to select -- I just don't want it to turn into a Hydra). Any input would be most appreciated. My apologies if the question is a bit incoherent. It is late, and I my brain is toast. Best.

  Read the article

• AnkhSVN: Cannot checkout Subsolution due to existing "versioned" folder

  - by lostiniceland

  Hello Everyone I am using Subversion since quite some time for Java-Development and I have setup a repository on my local NAS. Since I have a MSDN subscription via my company I recently installed Visual Studio 2010 to do a small project with .NET. According to some "best-practices" my project folder looks like the following. MySolution main.sln Services services.sln Service A files Service A Test files View projectfiles Persistence persistence.sln PersistenceXml files PersistenceXml Test files PersistenceDB files PersistenceDB Test files The idea is, that the main.sln only contains the projects for the application, meaning no test projects. The subsolutions, contain the project(s) and their corresponding testprojects. I was able to put all those projects under versioncontrol with AnkhSVN, so I have the same structure there in my trunk. Commiting changes was also no problem. Now I would like to check the this out on another machine. I was able to check out the main.sln which downloaded everything that was inside this solution. It skipped the services.sln, persistence.sln and all the test-projects. Until now everything is fine. Now, here comes the problem: when I am tryting to check out the subsolution (eg. services.sln) I get an error, I think it was UnsupportedOperation. I guess this happens because ankhsvn is tryting to download the folder Service A again and create ist hidden .svn folder which is already present. The only workaround I can think of by now is installing Tortoise SVN and check out the whole thing at once. It would be nicer though to have everything from within VS. Does anyone know how I can solve this? Is another client the only solution?

  Read the article

• C#. How to pass message from unsafe callback to managed code?

  - by maxima120

  Is there a simple example of how to pass messages from unsafe callback to managed code? I have a proprietary dll which receives some messages packed in structs and all is coming to a callback function. The example of usage is as follows but it calls unsafe code too. I want to pass the messages into my application which is all managed code. *P.S. I have no experience in interop or unsafe code. I used to develop in C++ 8 yrs ago but remember very little from that nightmarish times :) P.P.S. The application is loaded as hell, the original devs claim it processes 2mil messages per sec.. I need a most efficient solution.* static unsafe int OnCoreCallback(IntPtr pSys, IntPtr pMsg) { // Alias structure pointers to the pointers passed in. CoreSystem* pCoreSys = (CoreSystem*)pSys; CoreMessage* pCoreMsg = (CoreMessage*)pMsg; // message handler function. if (pCoreMsg->MessageType == Core.MSG_STATUS) OnCoreStatus(pCoreSys, pCoreMsg); // Continue running return (int)Core.CALLBACKRETURN_CONTINUE; } Thank you.

  Read the article

• In SQL can I return a tables with a varying number of columns

  - by Matt

  I have a somewhat more complicated scenario, but I think it should be possible. I have a large SPROC whose result is a set of characteristics for a set of persons. So the Table would look something like this: Property | Client1 Client 2 Client3 ----------------------------------------------------------- Sex | M F M Age | 67 56 67 Income | Low Mid Low It's built using cursors, iterating over different datasets. The problem I am facing is that there is a varying number of Clients and Properties, so an equally valid result over different input sets might be: Property | Client1 Client 2 ------------------------------------------- Sex | M F Age | 67 56 Weight | 122 122 The different number of properties is easy, those are just extra rows. My problem is that I need to declare a temporary table with a varying number of columns. There could be 2 clients or 100. Every client in guaranteed to have every property ultimately listed. What SQL structure would statisfy this and how can I declare it and insert things into it? I can't just flip the columns and rows either because there is a variable number of each.

  Read the article

• Creating a Linq->HQL provider

  - by Mike Q

  Hi all, I have a client application that connects to a server. The server uses hibernate for persistence and querying so it has a set of annotated hibernate objects for persistence. The client sends HQL queries to the server and gets responses back. The client has an auto-generated set of objects that match the server hibernate objects for query results and basic persistence. I would like to support using Linq to query as well as Hql as it makes the queries typesafe and quicker to build (no more typos in HQL string queries). I've looked around at the following but I can't see how to get them to fit with what I have. NHibernate's Linq provider - requires using NHibernate ISession and ISessionFactory, which I don't have LinqExtender - requires a lot of annotations on the objects and extending a base type, too invasive What I really want is something that will generate give me a nice easy to process structure to build the HQL queries from. I've read most of a 15 page article written by one of the C# developers on how to create custom providers and it's pretty fraught, mainly because of the complexity of the expression tree. Can anyone suggest an approach for implementing Linq - HQL translation? Perhaps a library that will the cleanup of the expression tree into something more SQL/HQLish. I would like to support select/from/where/group by/order by/joins. Not too worried about subqueries.

  Read the article

• Integer array or struct array - which is better?

  - by MusiGenesis

  In my app, I'm storing Bitmap data in a two-dimensional integer array (int[,]). To access the R, G and B values I use something like this: // read: int i = _data[x, y]; byte B = (byte)(i >> 0); byte G = (byte)(i >> 8); byte R = (byte)(i >> 16); // write: _data[x, y] = BitConverter.ToInt32(new byte[] { B, G, R, 0 }, 0); I'm using integer arrays instead of an actual System.Drawing.Bitmap because my app runs on Windows Mobile devices where the memory available for creating bitmaps is severely limited. I'm wondering, though, if it would make more sense to declare a structure like this: public struct RGB { public byte R; public byte G; public byte B; } ... and then use an array of RGB instead of an array of int. This way I could easily read and write the separate R, G and B values without having to do bit-shifting and BitConverter-ing. I vaguely remember something from days of yore about byte variables being block-aligned on 32-bit systems, so that a byte actually takes up 4 bytes of memory instead of just 1 (but maybe this was just a Visual Basic thing). Would using an array of structs (like the RGB example` above) be faster than using an array of ints, and would it use 3/4 the memory or 3 times the memory of ints?

  Read the article

• MySQL SELECT combining 3 SELECTs INTO 1

  - by Martin Tóth

  Consider following tables in MySQL database: entries: creator_id INT entry TEXT is_expired BOOL other: creator_id INT entry TEXT userdata: creator_id INT name VARCHAR etc... In entries and other, there can be multiple entries by 1 creator. userdata table is read only for me (placed in other database). I'd like to achieve a following SELECT result: +------------+---------+---------+-------+ | creator_id | entries | expired | other | +------------+---------+---------+-------+ | 10951 | 59 | 55 | 39 | | 70887 | 41 | 34 | 108 | | 88309 | 38 | 20 | 102 | | 94732 | 0 | 0 | 86 | ... where entries is equal to SELECT COUNT(entry) FROM entries GROUP BY creator_id, expired is equal to SELECT COUNT(entry) FROM entries WHERE is_expired = 0 GROUP BY creator_id and other is equal to SELECT COUNT(entry) FROM other GROUP BY creator_id. I need this structure because after doing this SELECT, I need to look for user data in the "userdata" table, which I planned to do with INNER JOIN and select desired columns. I solved this problem with selecting "NULL" into column which does not apply for given SELECT: SELECT creator_id, COUNT(any_entry) as entries, COUNT(expired_entry) as expired, COUNT(other_entry) as other FROM ( SELECT creator_id, entry AS any_entry, NULL AS expired_entry, NULL AS other_enry FROM entries UNION SELECT creator_id, NULL AS any_entry, entry AS expired_entry, NULL AS other_enry FROM entries WHERE is_expired = 1 UNION SELECT creator_id, NULL AS any_entry, NULL AS expired_entry, entry AS other_enry FROM other ) AS tTemp GROUP BY creator_id ORDER BY entries DESC, expired DESC, other DESC ; I've left out the INNER JOIN and selecting other columns from userdata table on purpose (my question being about combining 3 SELECTs into 1). Is my idea valid? = Am I trying to use the right "construction" for this? Are these kind of SELECTs possible without creating an "empty" column? (some kind of JOIN) Should I do it "outside the DB": make 3 SELECTs, make some order in it (let's say python lists/dicts) and then do the additional SELECTs for userdata? Solution for a similar question does not return rows where entries and expired are 0. Thank you for your time.

  Read the article

• How do I detect proximity of the mouse pointer to a line in Flex?

  - by Hanno Fietz

  I'm working on a charting UI in Flex. One of the features I want to implement is "snapping" of the mousepointer to the data points in the diagram. I. e., if the user hovers the mouse pointer over a line diagram and gets close to the data point, I want the pointer to move to the exact coordinates and show a marker, like this: Currently, the lines are drawn on a Shape, using the Graphics API. The Shape is a child DisplayObject of a custom UIComponent subclass with the exact same dimensions. This means, I already get mouseOver events on the parent of the diagram's canvas. Now I need a way to detect if the pointer is close to one of the data points. I. e. I need an answer to the question "Which data points lie within a radius of x pixels from my current position and which of them is closest?" upon each move of the mouse. I can think of the following possibilities: draw the lines not as simple lines in the graphics API, but as more advanced objects that can have their own mouseOver events. However, I want the snapping to trigger before the mouse is actually over the line. check the original data for possible candidates upon each mouse movement. Using binary search, I might be able to reduce the number of items I have to compare sufficently. prepare some kind of new data structure from the raw data that makes the above search more efficient. I don't know how that would look like. I'm guessing this is a pretty standard problem for a number of applications, but probably the actual code usually is inside of some framework. Is there anything I can read about this topic?

  Read the article

• How do I create a graph from this datastructure?

  - by Shawn Mclean

  I took this data structure from this A* tutorial: public interface IHasNeighbours<N> { IEnumerable<N> Neighbours { get; } } public class Path<TNode> : IEnumerable<TNode> { public TNode LastStep { get; private set; } public Path<TNode> PreviousSteps { get; private set; } public double TotalCost { get; private set; } private Path(TNode lastStep, Path<TNode> previousSteps, double totalCost) { LastStep = lastStep; PreviousSteps = previousSteps; TotalCost = totalCost; } public Path(TNode start) : this(start, null, 0) { } public Path<TNode> AddStep(TNode step, double stepCost) { return new Path<TNode>(step, this, TotalCost + stepCost); } public IEnumerator<TNode> GetEnumerator() { for (Path<TNode> p = this; p != null; p = p.PreviousSteps) yield return p.LastStep; } IEnumerator IEnumerable.GetEnumerator() { return this.GetEnumerator(); } } I have no idea how to create a simple graph with. How do I add something like the following undirected graph using C#: Basically I'd like to know how to connect nodes. I have my own datastructures that I can already determine the neighbors and the distance. I'd now like to convert that into this posted datastructure so I can run it through the AStar algorithm. I was seeking something more like: Path<EdgeNode> startGraphNode = new Path<EdgeNode>(tempStartNode); startGraphNode.AddNeighbor(someOtherNode, distance);

  Read the article

< Previous Page | 863 864 865 866 867 868 869 870 871 872 873 874  | Next Page >