Search Results

Search found 17610 results on 705 pages for 'specific'.

Page 577/705 | < Previous Page | 573 574 575 576 577 578 579 580 581 582 583 584  | Next Page >

• Associate File Extension with Application

  - by fneep

  I've written a program that edits a specific filetype , and I want to give the user the option to set my application as the default editor for this filetype (since I don't want an installer) on startup. I've tried to write a re-useable method that associates a file for me (preferably on any OS, although I'm running Vista) by adding a key to HKEY_CLASSES_ROOT, and am using it with my application, but it doesn't seem to work. public static void SetAssociation(string Extension, string KeyName, string OpenWith, string FileDescription) { RegistryKey BaseKey; RegistryKey OpenMethod; RegistryKey Shell; RegistryKey CurrentUser; BaseKey = Registry.ClassesRoot.CreateSubKey(Extension); BaseKey.SetValue("", KeyName); OpenMethod = Registry.ClassesRoot.CreateSubKey(KeyName); OpenMethod.SetValue("", FileDescription); OpenMethod.CreateSubKey("DefaultIcon").SetValue("", "\"" + OpenWith + "\",0"); Shell = OpenMethod.CreateSubKey("Shell"); Shell.CreateSubKey("edit").CreateSubKey("command").SetValue("", "\"" + OpenWith + "\"" + " \"%1\""); Shell.CreateSubKey("open").CreateSubKey("command").SetValue("", "\"" + OpenWith + "\"" + " \"%1\""); BaseKey.Close(); OpenMethod.Close(); Shell.Close(); CurrentUser = Registry.CurrentUser.CreateSubKey(@"HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.ucs"); CurrentUser = CurrentUser.OpenSubKey("UserChoice", RegistryKeyPermissionCheck.ReadWriteSubTree, System.Security.AccessControl.RegistryRights.FullControl); CurrentUser.SetValue("Progid", KeyName, RegistryValueKind.String); CurrentUser.Close(); }

  Read the article

• Rails3 renders a js.erb template with a text/html content-type instead of text/javascript

  - by Yannis

  Hi, I'm building a new app with 3.0.0.beta3. I simply try to render a js.erb template to an Ajax request for the following action (in publications_controller.rb): def get_pubmed_data entry = Bio::PubMed.query(params[:pmid])# searches PubMed and get entry @publication = Bio::MEDLINE.new(entry) # creates Bio::MEDLINE object from entry text flash[:warning] = "No publication found."if @publication.title.blank? and @publication.authors.blank? and @publication.journal.blank? respond_to do |format| format.js end end Currently, my get_pubmed_data.js.erb template is simply alert('<%= @publication.title %>') The server is responding with the following alert('Evidence for a herpes simplex virus-specific factor controlling the transcription of deoxypyrimidine kinase.') which is perfectly fine except that nothing happen in the browser, probably because the content-type of the response is 'text/html' instead of 'text/javascript' as shown by the response header partially reproduced here: Status 200 Keep-Alive timeout=5, max=100 Connection Keep-Alive Transfer-Encoding chunked Content-Type text/html; charset=utf-8 Is this a bug or am I missing something? Thanks for your help!

  Read the article

• TSQL - make a literal float value

  - by David B

  I understand the host of issues in comparing floats, and lament their use in this case - but I'm not the table author and have only a small hurdle to climb... Someone has decided to use floats as you'd expect GUIDs to be used. I need to retrieve all the records with a specific float value. sp_help MyTable -- Column_name Type Computed Length Prec -- RandomGrouping float no 8 53 Here's my naive attempt: --yields no results SELECT RandomGrouping FROM MyTable WHERE RandomGrouping = 0.867153569942739 And here's an approximately working attempt: --yields 2 records SELECT RandomGrouping FROM MyTable WHERE RandomGrouping BETWEEN 0.867153569942739 - 0.00000001 AND 0.867153569942739 + 0.00000001 -- 0.867153569942739 -- 0.867153569942739 In my naive attempt, is that literal a floating point literal? Or is it really a decimal literal that gets converted later? If my literal is not a floating point literal, what is the syntax for making a floating point literal? EDIT: Another possibility has occurred to me... it may be that a more precise number than is displayed is stored in this column. It may be impossible to create a literal that represents this number. I will accept answers that demonstrate that this is the case. EDIT: response to DVK. TSQL is MSSQLServer's dialect of SQL. This script works, and so equality can be performed deterministically between float types: DECLARE @X float SELECT top 1 @X = RandomGrouping FROM MyTable WHERE RandomGrouping BETWEEN 0.839110948199148 - 0.000000000001 AND 0.839110948199148 + 0.000000000001 --yields two records SELECT * FROM MyTable WHERE RandomGrouping = @X I said "approximately" because that method tests for a range. With that method I could get values that are not equal to my intended value. The linked article doesn't apply because I'm not (intentionally) trying to straddle the world boundaries between decimal and float. I'm trying to work with only floats. This isn't about the non-convertibility of decimals to floats.

  Read the article

• Complex SQL query, one to many relationship

  - by Ethan

  Hey SO, I have a query such that I need to get A specific dog All comments relating to that dog The user who posted each comment All links to images of the dog the user who posted each link I've tried a several things, and can't figure out quite how to work it. Here's what I have (condensed so you don't have to wade through it all): SELECT s.dog_id, s.name, c.comment, c.date_added AS comment_date_added, u.username AS comment_username, u.user_id AS comment_user_id, l.link AS link, l.date_added AS link_date_added, u2.username AS link_username, u2.user_id AS link_user_id FROM dogs AS d LEFT JOIN comments AS c ON c.dog_id = d.dog_id LEFT JOIN users AS u ON c.user_id = u.user_id LEFT JOIN links AS l ON l.dog_id = d.dog_id LEFT JOIN users AS u2 ON l.user_id = u2.user_id WHERE d.dog_id = '1' It's sorta close to working, but it'll only return me the first comment, and the first link all as one big array with all the info i requested. The are multiple comments and links per dog, so I need it to give me all the comments and all the links. Ideally it'd return an object with dog_id, name, comments(an array of the comments), links(an array of the links) and then comments would have a bunch of comments, date_added, username, and user_id and links would have a bunch of links with link, date_added, username and user_id. It's got to work even if there are no links or comments. I learned the basics of mySQL somewhat recently, but this is pretty far over my head. Any help would be wonderful. Thanks!

  Read the article

• general learning methodology

  - by momo

  just wanted to hear on the different general learning paths people embark on when learning a new language/framework. the one i currently use, which is how i learned bash and am currently learning python, is: instant hacking tutorial (very short tutorial introducing the basic syntax, variable declaration, loops, data types, etc. and how they are generally used) in depth tutorial with good programming style and slightly topic-specific (e.g. Mark Pilgrim's Dive into Python), important topics for me personally are regex methods, file IO, and ways the different data types are utilized best (i wrote a very primitive bayesian spam filter using python's dictionaries to keep track of word occurrences) spaced-repition of syntax or short recipes (i use anki, with questions like 'create dictionary with filename and filesize metadata, human-readable' or simpler ones like 'match 0 - 3 occurences of the letter M in a string', or 'return/create an iterator from two sequences') the use of spaced-repitition has been invaluable, and i credit it with the ease that i can recall/create python algorithms. however, i've recently started looking into django, and i've found that spaced-repitition, at least in my case, doesn't work very well for learning a framework, it works best with short code recipes (either that or i should start looking into more basic django framework tutorials). the problem i'm encountering is that since framework programming is not only algorithms, but actually learning the API, which can be quite complex since you have to learn all the methods, modules, the places where they are stored, and the sequence of which things have to be done. for ex. in django to start a project that deals with polls (from the django tutorial), one has to create the project, edit the settings.py file, create the polls app, edit the models.py file (which requires knowing the classes that are present in the module models), edit the urls.py file, etc. i found that my spaced-repition method didn't work very well for this type of learning, so i wanted to ask you guys what method(s) you use for learning the different frameworks/APIs.

  Read the article

• Which software for intranet CMS - Django or Joomla?

  - by zalun

  In my company we are thinking of moving from wiki style intranet to a more bespoke CMS solution. Natural choice would be Joomla, but we have a specific architecture. There is a few hundred people who will use the system. System should be self explainable (easier than wiki). We use a lot of tools web, applications and integrated within 3rd party software. The superior element which is a glue for all of them is API. In example for the intranet tools we do use Django, but it's used without ORM, kind of limited to templates and url - every application has an adequate methods within our API. We do not use the Django admin interface, because it is hardly dependent on ORM. Because of that Joomla may be hard to integrate. Every employee should be able to edit most of the pages, authentication and privileges have to be managed by our API. How hard is it to plug Joomla to use a different authentication process? (extension only - no hacks) If one knows Django better than Joomla, should Django be used?

  Read the article

• Images in Applet not showing in web page

  - by Leanne C

  I am trying to display a JPEG image and a moving dot on a Java applet which I am using on a web based application. However, when I run the applet it works fine, but when I display the applet from the JSP page, I get the moving dot but not the JPEG image. Is there a specific folder where the JPEG needs to be? These are the 2 methods i use for drawing the picture and the moving dot on the screen. public class mapplet extends Applet implements Runnable { int x_pos = 10; int y_pos = 100; int radius = 20; Image img, img2; Graphics gr; URL base; MediaTracker m; @Override public void init() { mt = new MediaTracker(this); try { //getDocumentbase gets the applet path. base = getCodeBase(); img = getImage(base, "picture.jpg"); m.addImage(img, 1); m.waitForAll(); } catch (InterruptedException ex) { Logger.getLogger(movement.class.getName()).log(Level.SEVERE, null, ex); } public void paint (Graphics g) { g.drawImage(img, 0, 0, this); // set color g.setColor (Color.red); // paint a filled colored circle g.fillOval (x_pos - radius, y_pos - radius, 2 * radius, 2 * radius); } The code one below is the call from the jsp page <applet archive="mapplet.jar" code="myapplets/mapplet.class" width=350 height=200> </applet> The jar file and the picture are in the same folder as the jsp page, and there is also a folder containing the contents of the class and image of the applet in the web section of the application. The applet loads fine however the picture doesn't display. I think it's not the code but the location of the picture that is causing a problem. Thanks

  Read the article

• Static Libraries on iPhone device

  - by Akusete

  I have two projects, a Cocoa iPhone application and a static library which it uses. I've tested it successfully on the iPhone simulator, but when I try to deploy it to my iPhone device I get (symbol not found) link errors. If I remove the dependancy of the library the project builds/runs fine. I have made sure all the build settings are set to iPhoneOS not the simulator. Im sure its something simple, but has anyone run into similar problems moving from iPhone simulator to device? --EDIT: I have managed to create new projects (one for the application and one for the static library), and successfully get them to run on the iPhone or simulator. But I have a very strange problem... for each specific project I cannot get it working for BOTH the device and the simulator... I have double checked the build settings, made sure the libraries that are being references are for the matching build settings (I believe) but I cannot resolve these linking errors. I think I must be doing something very wrong... all the apple documentation says 'its super simple - one click' but this is giving me a lot of problems. This is probably something to do with xCode build settings, but I cannot seem to understand why selecting the different build platforms and rebuilding the libraries does not work.

  Read the article

• Web application architecture, and application servers?

  - by seanieb

  Hi, I'm building a web application, and I need to use an architecture that allows me to run it on two servers. The application scrapes information from other sites periodically, and on input from the end user. To do this I'm using Php+curl to scrape the information, Php or python to parse it and store the results in a MySQLDB. Then I will use Python to run some algorithms on the data, this will happen both periodically and on input from the end user. I'm going to cache some of the results in the MySQL DB and sometimes if it is specific to the user, skip storing the data and serve it to the user. I'm think of using Php for the website front end on a separate web server, running the Php spider, MySQL DB and python on another server. As you can see I'm fairly clueless. I'm familiar with using Php, MySQL and the basics of Python, but bringing this all together using something more complex than a cron job is new to me. How do go about implementing this? What frame work(s) should I use? Is MVC a good architecture for this? (I'm new to MVC, architectures etc.) Is Cakephp a good solution? If so will I be able to control and monitor the Python code using it?

  Read the article

• How can I visualise a "broken" hierarchical dataset?

  I have a reasonably large datatable structured something like this: StaffNo Grade Direct Boss2 Boss3 Boss4 Boss5 Boss6 ------- ----- ----- ----- ----- ----- ----- ----- 10001 1 10002 10002 10057 10094 10043 10099 10002 2 10057 NULL 10057 10094 10043 10099 10003 1 10004 10004 10057 10094 10043 10099 10004 2 10057 NULL 10057 10094 10043 10099 10057 3 10094 NULL NULL 10094 10043 10099 etc.... i.e. a unique id , their level (grade) in the hierarchy, a record of their bosses ID and the IDs of the supervisors above. (The 2,3,4, etc refers to the boss at that particular grade). The system relies on a strict hierarchy - if you are my boss (/parent) then your boss must be my grandparent. Unfortunately this rule is not enforced within the data model and the data ultimately comes from other systems which don't even know about the rule, let alone observe it. So you and I may share the same boss, but our bosses boss won't be the same. note: I cannot change the data model I cannot fix the data at source. So (for the moment) I have to fix the data once it's in place. Once a fortnight someone will do something which breaks the model and I'll need to modify the procs slightly to resolve. Not ideal, but I'm stuck with this for the next six months. Anyway, specific queries are easy to produce but I find it hard to keep track of the bigger picutre. The application which sits on this runs without complaint regardless but navigating around the system becoming extraordinarily confusing. So my question is: Can anyone recommend a tool (or technique) for generating some kind of "broken tree" diagram in this sort of circumstances? I don't want something that will fix things for me, or attempt statistical analysis but at least something that will give a visual indication of how broken it is at any one time. Note : At the moment this is in a SQL Server database but I'm open to ideas utilising C#, Perl or Python.

  Read the article

• Python: circular imports needed for type checking

  - by phild

  First of all: I do know that there are already many questions and answers to the topic of the circular imports. The answer is more or less: "Design your Module/Class structure properly and you will not need circular imports". That is true. I tried very hard to make a proper design for my current project, I in my opinion I was successful with this. But my specific problem is the following: I need a type check in a module that is already imported by the module containing the class to check against. But this throws an import error. Like so: foo.py: from bar import Bar class Foo(object): def __init__(self): self.__bar = Bar(self) bar.py: from foo import Foo class Bar(object): def __init__(self, arg_instance_of_foo): if not isinstance(arg_instance_of_foo, Foo): raise TypeError() Solution 1: If I modified it to check the type by a string comparison, it will work. But I dont really like this solution (string comparsion is rather expensive for a simple type check, and could get a problem when it comes to refactoring). bar_modified.py: from foo import Foo class Bar(object): def __init__(self, arg_instance_of_foo): if not arg_instance_of_foo.__class__.__name__ == "Foo": raise TypeError() Solution 2: I could also pack the two classes into one module. But my project has lots of different classes like the "Bar" example, and I want to seperate them into different module files. After my own 2 solutions are no option for me: Has anyone a nicer solution for this problem?

  Read the article

• How to make safe frequent DataSource switches for AbstractRoutingDataSource?

  - by serg555

  I implemented Dynamic DataSource Routing for Spring+Hibernate according to this article. I have several databases with same structure and I need to select which db will run each specific query. Everything works fine on localhost, but I am worrying about how this will hold up in real web site environment. They are using some static context holder to determine which datasource to use: public class CustomerContextHolder { private static final ThreadLocal<CustomerType> contextHolder = new ThreadLocal<CustomerType>(); public static void setCustomerType(CustomerType customerType) { Assert.notNull(customerType, "customerType cannot be null"); contextHolder.set(customerType); } public static CustomerType getCustomerType() { return (CustomerType) contextHolder.get(); } public static void clearCustomerType() { contextHolder.remove(); } } It is wrapped inside some ThreadLocal container, but what exactly does that mean? What will happen when two web requests call this piece of code in parallel: CustomerContextHolder.setCustomerType(CustomerType.GOLD); //<another user will switch customer type here to CustomerType.SILVER in another request> List<Item> goldItems = catalog.getItems(); Is every web request wrapped into its own thread in Spring MVC? Will CustomerContextHolder.setCustomerType() changes be visible to other web users? My controllers have synchronizeOnSession=true. How to make sure that nobody else will switch datasource until I run required query for current user? Thanks.

  Read the article

• Core Data: Deleting causes 'NSObjectInaccessibleException' from NSOperation with a reference to a deleted object

  - by Bryan Irace

  My application has NSOperation subclasses that fetch and operate on managed objects. My application also periodically purges rows from the database, which can result in the following race condition: An background operation fetches a bunch of objects (from a thread-specific context). It will iterate over these objects and do something with their properties. A bunch of rows are deleted in the main managed object context. The background operation accesses a property on an object that was deleted from the main context. This results in an 'NSObjectInaccessibleException', reason: 'CoreData could not fulfill a fault' Ideally, the objects that are fetched by the NSOperation can be operated on even if one is deleted in the main context. The best way I can think to achieve this is either to: Call [request setReturnsObjectsAsFaults:NO] to ensure that Core Data won't try to fulfill a fault for an object that no longer exists in the main context. The problem here is I may need to access the object's relationships, which (to my understanding) will still be faulted. Iterate through the managed objects up front and copy the properties I will need into separate non-managed objects. The problem here is that (I think) I will need to synchronize/lock this part, in case an object is deleted in the main context before I can finish copying. Am I missing something obvious? It doesn't seem like what I'm trying to accomplish is too out of the ordinary. Thanks for your help.

  Read the article

• sharing message object between web applications

  - by jezhilvalan

  I need to share java mail message objects between two web applications(A and B). WebApplication A obtains the message and write it to the outputStream for(int i=0;i<messagesArr.length;i++){ uid = pop3FolderObj.getUID(messagesArr[i]); //storing messages with uid names inorder to maintain uniqueness File f = new File("F:/PersistedMessagesFolder" + uid); FileOutputStream fos = new FileOutputStream(f); messagesArr[i].writeTo(fos); fos.flush(); fos.close(); } Is FileOutputStream the best output stream for persisting message objects? Is it possible to use ObjectOutputStream for message object persistence? WebApplication B reads the message object via InputStream FileInputStream fis = new FileInputStream("F:/MessagesPersistedFolder"+uid); MimeMessage mm = new MimeMessage(sessionObj,fis); What if the mail message object which is already written via WebApplication A is not a MimeMessage? How can I read non-mime messages using input stream? MimeMessage constructor mandates sessionObj as the first parameter? How can I obtain this sessionObj in WebApplicationB? Do I have to again establish store connection with the same emailid,emailpassword,popserver and port(already used in WebApplication A) with the email server inorder to obtain this session object? Even if obtained, will this session object remains the same as that of the session object which is priorly obtained in WebApplicationA? Since I am using uids to name Message objects (inorder to maintain uniqueness of file names) how can I share these uids between WebApplication A and WebApplication B? WebApplication B needs the uid inorder to access the specific file which is present in "F:/MessagesPersistedFolder" Please help me in resolving the aforeseen issues.

  Read the article

• DataGrid calculate difference between values in two databound cells

  - by justMe

  Hello! In my small application I have a DataGrid (see screenshot) that's bound to a list of Measurement objects. A Measurement is just a data container with two properties: Date and CounterGas (float). Each Measurement object represents my gas consumption at a specific date. The list of measurements is bound to the DataGrid as follows: <DataGrid ItemsSource="{Binding Path=Measurements}" AutoGenerateColumns="False"> <DataGrid.Columns> <DataGridTextColumn Header="Date" Binding="{Binding Path=Date, StringFormat={}{0:dd.MM.yyyy}}" /> <DataGridTextColumn Header="Counter Gas" Binding="{Binding Path=ValueGas, StringFormat={}{0:F3}}" /> </DataGrid.Columns> </DataGrid> Well, and now my question :) I'd like to have another column right next to the column "Counter Gas" which shows the difference between the actual counter value and the last counter value. E.g. this additional column should calculate the difference between the value of of Feb. 13th and Feb. 6th = 199.789 - 187.115 = 15.674 What is the best way to achieve this? I'd like to avoid any calculation in the Measurement class which should just hold the data. I'd rather more like the DataGrid to handle the calculation. So is there a way to add another column that just calculates the difference between to values? Maybe using some kind of converter and extreme binding? ;D P.S.: Maybe someone with a better reputation could embed the screenshot. Thanks :)

  Read the article

• One config file for multiple environments

  - by ho

  I'm currently working with systems that has quite a lot of configuration settings that are environment specific (Dev, UAT, Production). Does anyone have any suggestions for minimizing the changes needed to the config file when moving between environments as well as minimizing the duplication of data in the config file? It's mostly Application settings rather than User settings. The way I'm doing it at the moment is something similar to this: <DevConnectionString>xyz</DevConnectionString> <DevInboundPath>xyz</DevInboundPath> <DevProcessedPath>xyz</DevProcessedPath> <UatConnectionString>xyz</UatConnectionString> <UatInboundPath>xyz</UatInboundPath> <UatProcessedPath>xyz</UatProcessedPath> ... <Environment>Dev</Environment> And then I have a class that reads in the Environment setting via the My.Settings class (it's VB project) and then uses that to decide what other settings to retrieve. This leads to too much duplication though so I'm not sure if it's worth it.

  Read the article

• How to accommodate for the iPhone 4 screen resolution?

  - by dontWatchMyProfile

  This is a programming question! Read on before you vote to close! According to Apple, the iPhone 4 has a new and better screen resolution: 3.5-inch (diagonal) widescreen Multi-Touch display 960-by-640-pixel resolution at 326 ppi This little detail affects our apps in a heavy way. Most of the demo apps on the net have one thing in common: They position views in the believe that the screen has a fixed size of 320 x 480 pixels. So what most -if not all- developers do is: They designed everything in such a way, that a touchable area is -for example- 50 x 50 pixels big. Just enough to tap it. Things have been positioned relative to the upper left, to reach a specific position on screen - let's say the center, or somewhere at the bottom. Edit: It seems Apple has integrated an switch that allows to tell if an app is highRes or not. Nice. When we develop high-resolution apps, they probably won't work on older devices. And if they do, they would suffer a lot from 4-times the size of any image, having to scale them down in memory.

  Read the article

• In IE8, jquery-ui's dialog set the height of its contents to zero. How can I fix this?

  - by brahn

  I am using jquery UI's dialog widget to render a modal dialog in my web application. I do this by passing the ID of the desired DOM element into the following function: var setupDialog = function (eltId) { $("#" + eltId).dialog({ autoOpen: false, width: 610, minWidth: 610, height: 450, minHeight: 200, modal: true, resizable: false, draggable: false, }); }; Everything works just fine in Firefox, Safari, and Chrome. However, in IE 8 when the dialog is opened only the div.ui-dialog-titlebar is visible -- the div.ui-dialog-contents are not. The problem seems to be that while in the modern browsers, the div.ui-dialog-contents has a specific height set in its style, i.e. after opening the dialog, the resulting HTML is: <div class="ui-dialog-content ui-widget-content" id="invite-friends-dialog" style="width: auto; min-height: 198px; height: 448px">...</div> while in IE8 the height style attribute is set to zero, and the resulting HTML is: <div class="ui-dialog-content ui-widget-content" id="invite-friends-dialog" style="min-height: 0px; width: auto; height: 0px">...</div> What do I need to do to get the height (and min-height) style attributes set correctly?

  Read the article

• The rules to connect a web service trough the SSL and Certificates

  - by blgnklc

  There is a web service running on tomcat on a server. It is built on Java Servlet. It is listening others to call itself on a SSL enabled http port. so its web service adreess looks like: https://172.29.12.12/axis/services/XYZClient?wsdl On the other hand I want to connect the web service above from a windows application which is built on .NET frame work. Finally, when I want to connect the web service from my computer; I get some specific erros; Firstly I get; Proxy authentication error; then I added some new line to my code; Dim cr As System.Net.NetworkCredential = New System.Net.NetworkCredential("xname", "xsurname", "xdomainname") Dim myProxy As New WebProxy("http://mar.xxxyyy.com", True) myProxy.Credentials = cr Secondly, after this modifications It says that bad request. I did not get over this error. Moreover I did try to connect the web server on the same computer. I copied my executable program to the computer where the web service runs. The error was like; The underlying connection was closed: Could not establish trust relationship for SSL/TLS secure channel PS: When I try to connect to web service by using Internet Explorer; I see firstly some warnings about accepting an unknown certificate and I click take me to web service an I get there clearly. I want to know what are the basic elements to connect a web service, could you please tell me the requirements that I have to use on my windows project. regards bk

  Read the article

• Clustered index - multi-part vs single-part index and effects of inserts/deletes

  - by Anssssss

  This question is about what happens with the reorganizing of data in a clustered index when an insert is done. I assume that it should be more expensive to do inserts on a table which has a clustered index than one that does not because reorganizing the data in a clustered index involves changing the physical layout of the data on the disk. I'm not sure how to phrase my question except through an example I came across at work. Assume there is a table (Junk) and there are two queries that are done on the table, the first query searches by Name and the second query searches by Name and Something. As I'm working on the database I discovered that the table has been created with two indexes, one to support each query, like so: --drop table Junk1 CREATE TABLE Junk1 ( Name char(5), Something char(5), WhoCares int ) CREATE CLUSTERED INDEX IX_Name ON Junk1 ( Name ) CREATE NONCLUSTERED INDEX IX_Name_Something ON Junk1 ( Name, Something ) Now when I looked at the two indexes, it seems that IX_Name is redundant since IX_Name_Something can be used by any query that desires to search by Name. So I would eliminate IX_Name and make IX_Name_Something the clustered index instead: --drop table Junk2 CREATE TABLE Junk2 ( Name char(5), Something char(5), WhoCares int ) CREATE CLUSTERED INDEX IX_Name_Something ON Junk2 ( Name, Something ) Someone suggested that the first indexing scheme should be kept since it would result in more efficient inserts/deletes (assume that there is no need to worry about updates for Name and Something). Would that make sense? I think the second indexing method would be better since it means one less index needs to be maintained. I would appreciate any insight into this specific example or directing me to more info on maintenance of clustered indexes.

  Read the article

• Is it wise to use temporary tables?

  - by Industrial

  Hi guys, We have a mySQL database table for products. We are utilizing a cache layer to reduce database load, but we think that it's a good idea to minimize the actual data needed to be stored in the cache layer to speed up the application further. All the products in the database, that is visible to visitors have a price attached to them: The prices are stored in a different table, called prices . There are multiple price categories depending on which discount level each visitor (customer) applies to. From time to time, there are campaigns which means that a special price for each product is available. The special prices are stored in a table called specials. Is it a bad to make a temp table that binds the tables together? It would only have the neccessary information and would ofcourse be cached. -------------|-------------|------------ | productId | hasPrice | hasSpecial -------------|-------------|------------ 1 | 1 | 0 2 | 1 | 1 By doing such, it would be super easy to know if the specific product really has a price, without having to iterate through the complete prices or specials table each time a product should be listed or presented. Are temp tables a common thing for web applications or is it just bad design?

  Read the article

• Linq is returning too many results when joined

  - by KallDrexx

  In my schema I have two database tables. relationships and relationship_memberships. I am attempting to retrieve all the entries from the relationship table that have a specific member in it, thus having to join it with the relationship_memberships table. I have the following method in my business object: public IList<DBMappings.relationships> GetRelationshipsByObjectId(int objId) { var results = from r in _context.Repository<DBMappings.relationships>() join m in _context.Repository<DBMappings.relationship_memberships>() on r.rel_id equals m.rel_id where m.obj_id == objId select r; return results.ToList<DBMappings.relationships>(); } _Context is my generic repository using code based on the code outlined here. The problem is I have 3 records in the relationships table, and 3 records in the memberships table, each membership tied to a different relationship. 2 membership records have an obj_id value of 2 and the other is 3. I am trying to retrieve a list of all relationships related to object #2. When this linq runs, _context.Repository<DBMappings.relationships>() returns the correct 3 records and _context.Repository<DBMappings.relationship_memberships>() returns 3 records. However, when the results.ToList() executes, the resulting list has 2 issues: 1) The resulting list contains 6 records, all of type DBMappings.relationships(). Upon further inspection there are 2 for each real relationship record, both are an exact copy of each other. 2) All relationships are returned, even if m.obj_id == 3, even though objId variable is correctly passed in as 2. Can anyone see what's going on because I've spent 2 days looking at this code and I am unable to understand what is wrong. I have joins in other linq queries that seem to be working great, and my unit tests show that they are still working, so I must be doing something wrong with this. It seems like I need an extra pair of eyes on this one :)

  Read the article

• m2eclipse: How to set Eclipse project settings when importing a maven project?

  - by Marius Andreiana

  Using m2eclipse Eclipse plugin, everybody on the dev team should be able to checkout source code, import Maven project in Eclipse and be good to go. I saw m2eclipse is being merged into Eclipse 3.7, and maven-eclipse-plugin won't be maintained any longer, so I'm looking for a m2eclipse-based solution (without running "mvn eclipse:clean eclipse:eclipse" before project import, which is what maven-eclipse-plugin does). maven-eclipse-plugin allows this in pom.xml <additionalConfig> <file> <name>.settings/com.google.gdt.eclipse.core.prefs</name> <content><![CDATA[ eclipse.preferences.version=2 jarsExcludedFromWebInfLib= warSrcDir=${project.build.directory}/${project.build.finalName} warSrcDirIsOutput=true ]]> </content> </file> The more general question is How would m2eclipse do something similar? For some cases, just saving the eclipse .settings/prefs file works (e.g. org.eclipse.jdt.ui.prefs), but in this case, com.google.gdt.eclipse.core.prefs is always overwritten on m2eclipse project import. A specific question is asked here, with no reply. Thanks! UPDATE: Not possible now, see request

  Read the article

• Special technology needed for browser based chat?

  - by orokusaki

  On this post, I read about the usage of XMPP. Is this sort of thing necessary, and more importantly, my main question expanded: Can a chat server and client be built efficiently using only standard HTTP and browser technologies (such as PHP and JS, or RoR and JS, etc)? Or, is it best to stick with old protocols like XMPP find a way to integrate them with my application? I looked into CampFire via LiveHTTPHeaders and Firebug for about 5 minutes, and it appears to use Ajax to send a request which is never answered until another chat happens. Is this just CampFire opening a new thread on the server to listen for an update and then returning a response to the request when the thread hears an update? I noticed that they're requesting on a specific port (8043 if memory serves me) which makes me think that they're doing something more complex than just what I mentioned. Also, the URL requested started with /tcp/ which I found interesting. Note: I don't expect to ever have more than 150 users live-chatting in all the rooms combined at the same time. I understand that if I was building a hosted pay for chat service like CampFire with thousands of concurrent users, it would behoove me to invest time in researching special technologies vs trying to reinvent the wheel in a simple way in my app. Also, if you're going to do it with server polling, how often would you personally poll to maximize response without slamming the server?

  Read the article

• Tablet interface for the physically disabled?

  - by Glenn

  My sister has Cerebral Palsy, which in her case means she has only gross motor control and her speech is slurred. Implications should be obvious: traditional computer/phone/tablet interfaces won't work for her and she can't speak clearly enough for speech recognition software to help her at all. She enjoys reading but has difficulty holding the book and/or turning a page. There are a few options for helping her use a computer, but nothing for tablets or eReaders. That's where you come in. I would like to make (or buy, if such a thing exists) a better interface to an Android tablet that would work for someone with little to no physical dexterity or speech ability. I'd also be interested in work on the Kindle or iPad, but I'm most familiar with Android so I'm starting there. I know Android has Bluetooth capability. Is it possible to interface a joystick to control the Android device? By "control", I mean the entire operating system - selecting an app, launching it, controlling the menus, etc. I want to give her control over the whole thing, not just a specific app. On a PC this can be accomplished by creating a generic USB HID interface and an arcade joystick to move the mouse over the screen and click on thigns. Is it possible to do something like that in Android? Any help you can offer would be greatly appreciated. Thanks!

  Read the article

< Previous Page | 573 574 575 576 577 578 579 580 581 582 583 584  | Next Page >