Search Results

Search found 56342 results on 2254 pages for 'object database'.

Page 348/2254 | < Previous Page | 344 345 346 347 348 349 350 351 352 353 354 355  | Next Page >

• A question about indexes regarding to the gain of inserts & updates in database

  - by Mestika

  Hi, I’m having a question about the fine line between the gain of an index to a table there is growing steadily in size every month and the gain of queries with an index. The situation is, that I’ve two tables, Table1 and Table2. Each table grows slowly but regularly each month (with about 100 new rows for Table1 and a couple of rows for Table2). My concrete question is whether to have an index or to drop it. I’ve made some measurement that an covering index on Table2 improve my SELECT queries and some rather much but again, I’ve to consider the pros and cons but having a really hard time to decide. For Table1 it might not be necessary to have an index because the SELECT queries there is not that common. I would appreciate any suggestion, tips or just good advice to what is a good solution. By the way, I’m using IBM DB2 version 9.7 as my Database system Sincerely Mestika

  Read the article

• C# animation - move object from A to B or by angle

  - by Nullstr1ng

  Hi am just doing a little animation which moves an object from point a to point b or by angle/radians. what I currently have is this Point CalcMove(Point pt, double angle, int speed) { Point ret = pt; ret.X = (int)(ret.X + speed * Math.Sin(DegToRad(angle))); ret.Y = (int)(ret.Y + speed * Math.Cos(DegToRad(angle))); return ret; } but it doesn't look what i expected. please help? update: oh and am using NETCF

  Read the article

• .NET | Persist multiple objects in minimum number of queries

  - by VarunGupta

  I have a list of objects which needs to be persisted in a SQL Server database table, where each object gets persisted as single record. i.e. List of objects result in insertion of multiple records. Trivial way of saving the objects is to loop over the list and fire a query/stored procedure/etc. for saving that record. But this results in multiple database interactions. Is there a way to persist the list of objects in lesser number of database interactions?

  Read the article

• running requestAnimationFrame from within a new object

  - by JVE999

  I'm having trouble running an animation. This is inside var ob1 = function() {};. When called, it runs for a while and then I get the error Uncaught RangeError: Maximum call stack size exceeded. However, this same structure has no problems running outside of the object. /////////////// Render the scene /////////////// this.render = function (){ renderer.render(scene,camera); if(isControls == true) controls.update(clock.getDelta()); this.animate(); //console.log(true); requestAnimationFrame(this.render()); } /////////////// Update objects /////////////// this.animate = function (){ console.log("!"); }

  Read the article

• Revisions: algorithm and data structure

  - by SODA

  Hi, I need ideas for structuring and processing data with revisions. For example, I have a database of objects (e.g. cars). Each object has a number of properties, which can be arbitrary, so there's no a set schema to describe these objects. These objects are probably saved as key-value pairs. Now I need to change property of an object. I don't want to completely rewrite it - I want to be able to go back and see history of changes to these properties, that's why I want to add new property and keep the old one (so I guess a timestamp would do the job of telling which property is the latest). At the same time I want to be able to get info about any object in a snap, with only latest versions of each of the properties. Any ideas what would be the best approach? At least please point me in the right direction. Thanks!

  Read the article

• Designing different Factory classes (and what to use as argument to the factories!)

  - by devoured elysium

  Let's say we have the following piece of code: public class Event { } public class SportEvent1 : Event { } public class SportEvent2 : Event { } public class MedicalEvent1 : Event { } public class MedicalEvent2 : Event { } public interface IEventFactory { bool AcceptsInputString(string inputString); Event CreateEvent(string inputString); } public class EventFactory { private List<IEventFactory> factories = new List<IEventFactory>(); public void AddFactory(IEventFactory factory) { factories.Add(factory); } //I don't see a point in defining a RemoveFactory() so I won't. public Event CreateEvent(string inputString) { try { //iterate through all factories. If one and only one of them accepts //the string, generate the event. Otherwise, throw an exception. return factories.Single(factory => factory.AcceptsInputString(inputString)).CreateEvent(inputString); } catch (InvalidOperationException e) { throw new InvalidOperationException("No valid factory found to generate this kind of Event!", e); } } } public class SportEvent1Factory : IEventFactory { public bool AcceptsInputString(string inputString) { return inputString.StartsWith("SportEvent1"); } public Event CreateEvent(string inputString) { return new SportEvent1(); } } public class MedicalEvent1Factory : IEventFactory { public bool AcceptsInputString(string inputString) { return inputString.StartsWith("MedicalEvent1"); } public Event CreateEvent(string inputString) { return new MedicalEvent1(); } } And here is the code that runs it: static void Main(string[] args) { EventFactory medicalEventFactory = new EventFactory(); medicalEventFactory.AddFactory(new MedicalEvent1Factory()); medicalEventFactory.AddFactory(new MedicalEvent2Factory()); EventFactory sportsEventFactory = new EventFactory(); sportsEventFactory.AddFactory(new SportEvent1Factory()); sportsEventFactory.AddFactory(new SportEvent2Factory()); } I have a couple of questions: Instead of having to add factories here in the main method of my application, should I try to redesign my EventFactory class so it is an abstract factory? It'd be better if I had a way of not having to manually add EventFactories every time I want to use them. So I could just instantiate MedicalFactory and SportsFactory. Should I make a Factory of factories? Maybe that'd be over-engineering? As you have probably noticed, I am using a inputString string as argument to feed the factories. I have an application that lets the user create his own events but also to load/save them from text files. Later, I might want to add other kinds of files, XML, sql connections, whatever. The only way I can think of that would allow me to make this work is having an internal format (I choose a string, as it's easy to understand). How would you make this? I assume this is a recurrent situation, probably most of you know of any other more intelligent approach to this. I am then only looping in the EventFactory for all the factories in its list to check if any of them accepts the input string. If one does, then it asks it to generate the Event. If you find there is something wrong or awkward with the method I'm using to make this happen, I'd be happy to hear about different implementations. Thanks! PS: Although I don't show it in here, all the different kind of events have different properties, so I have to generate them with different arguments (SportEvent1 might have SportName and Duration properties, that have to be put in the inputString as argument).

  Read the article

• Why does C# not provide the C++ style 'friend' keyword?

  - by Ash

  The C++ friend keyword allows a class A to designate class B as it's friend. This allows Class B to access the private/protected members of class A. I've never read anything as to why this was left out of C# (and VB.NET). Most answers to this earlier StackOverflow question seem to be saying it is a useful part of C++ and there are good reasons to use it. In my experience I'd have to agree. Another question seems to me to be really asking how to do something similar to friend in a C# application. While the answers generally revolve around nested classes, it doesn't seem quite as elegant as using the friend keyword. The original Design Patterns book uses the friend keyword regularly throughout its examples. So in summary, why is friend missing from C#, and what is the "best practice" way (or ways) of simulating it in C#? (By the way, the "internal" keyword is not the same thing, it allows ALL classes within the entire assembly to access internal members, friend allows you to give access to a class to just one other class.)

  Read the article

• C# - Rollback SqlTransaction in catch block - Problem with object accessability

  - by Marks

  Hi there. I've got a problem, and all articles or examples i found seem to not care about it. I want to do some database actions in a transaction. What i want to do is very similar to most examples: using (SqlConnection Conn = new SqlConnection(_ConnectionString)) { try { Conn.Open(); SqlTransaction Trans = Conn.BeginTransaction(); using (SqlCommand Com = new SqlCommand(ComText, Conn)) { /* DB work */ } } catch (Exception Ex) { Trans.Rollback(); return -1; } } But the problem is, that the SqlTransaction Trans is declared inside the try block. So it is not accessable in the catch() block. Most examples just do Conn.Open() and Conn.BeginTransaction() before the try block. But i think thats a bit risky, since both can throw multiple exceptions. Am I wrong, or do most people just ignore this risk? Whats the best solution to be able to rollback, if an exception happens. Thanks in advance, Marks

  Read the article

• Why Java interfaces can't have constructors?

  - by AndrejaKo

  This question showed up on my mid-term exams and I've been searching for correct answer for some time. I know that Java interfaces can't be directly instantiated so they don't need constructors and that they can have only public static final attributes so they don't need constructors to set them up but that's not the expected answer.

  Read the article

• Looking for a free tool to visualize object relationships for C#

  - by vfilby

  Here is my ideal solution: a free tool that reads a .csporj or .sln and generates a pretty picture that shows all the objects and how they are related. By relationships, I don't mean inheritance but rather dependency. For example, if we have a Car object and Car has a member variable Wheel, I would like that Car depends on Wheel to be visualized in the graph. I know visual studio can do inheritance graphs, but that is only half of what I am looking for. Is what I am looking for possible? Are there any tools that do something similar? Related question for java: http://stackoverflow.com/questions/1824261/are-there-any-tools-to-visualize-the-objects-being-used-in-a-program

  Read the article

• convert String "11-10-10 12:00:00" into Date Object

  - by Mahendra Athneria

  Hi, I want to convert String "11-10-10 12:00:00" into Date object but i am not able to do so. can you please help me out? below is the code snippet. i have the Date obj which has the value = Mon Oct 11 00:00:00 IST 2010 DateFormat newDateFormat = new SimpleDateFormat("dd-MM-yy hh:mm:ss"); String strDate = newDateFormat.format(tempDate); //**i got strDate as strDate is : 11-10-10 12:00:00** DateFormat newDateFormat1 = new SimpleDateFormat("dd-MM-yy hh:mm:ss"); try { tempDate = newDateFormat1.parse(strDate); // **getting tempDate as - Mon Oct 11 00:00:00 IST 2010** } catch (ParseException e) { // TODO Auto-generated catch block e.printStackTrace(); } Can someone help me to solve this issue? Regards, Mahendra Athneria Mumbai, India

  Read the article

• How to return a value when destroying/cleaning-up an object instance

  - by Mridang Agarwalla

  When I initiate a class in Python, I give it some values. I then call method in the class which does something. Here's a snippet: class TestClass(): def __init__(self): self.counter = 0 def doSomething(self): self.counter = self.counter + 1 print 'Hiya' if __name__ == "__main__": obj = TestClass() obj.doSomething() obj.doSomething() obj.doSomething() print obj.counter As you can see, everytime I call the doSomething method, it prints some text and increments an internal variable i.e. counter. When I initiate the class, i set the counter variable to 0. When I destroy the object, I'd like to return the internal counter variable. What would be a good way of doing this? I wanted to know if there were other ways apart from doing stuff like: accessing the variable directly. Like obj.counter. creating a method like getCounter. Thanks.

  Read the article

• How to connect to a SQLite database in iphone

  - by Lee

  I am attempting converting an application from VB6 to an iphone app. In the VB version, the database is in Access. But, I have read that I need to convert it to SQLite. How I amend the following code to switch from Access to SQLite? cnList = new ADODB.Connection(); rsList = new ADODB.Recordset(); cnList.Provider = "Microsoft.Jet.OLEDB.4.0;"; cnList.ConnectionString = "Persist Security Info=False;"+CString("Data Source=cbe.mdb"); cnList.Open();

  Read the article

• read java.security.key stored as object inside a file which is in jar

  - by Tal

  I saved a PublicKey instance in a file using ObjectOutputStream. This file is then stored inside a jar file which is then loaded by JBoss. I'm trying to read this file but it throws me an exception telling that it's not serializable. Here is the code : InputStream input = KeyLoader.class.getClassLoader().getResourceAsStream(resource); ObjectInputStream objectInputStream = new ObjectInputStream(input); Object obj = objectInputStream.readObject(); Key output = (Key) obj; objectInputStream.close(); return output; which throws me this exception An exception occurred: java.io.NotSerializableException

  Read the article

• Java Program Design Layout Recommendations?

  - by Leebuntu

  I've learned enough to begin writing programs from scratch, but I'm running into the problem of not knowing how to design the layout and implementation of a program. To be more precise, I'm having difficulty finding a good way to come up with an action plan before I dive in to the programming part. I really want to know what classes, methods, and objects I would need beforehand instead of just adding them along the way. My intuition is leading me to using some kind of charting software that gives a hierarchal view of all the classes and methods. I've been using OmniGraffle Pro and while it does seem to work somewhat, I'm still having trouble planning out the program in its entirety. How should I approach this problem? What softwares out there are available to help with this problem? Any good reads out there on this issue? Thanks so much! Edit: Oh yeah, I'm using Eclipse and I code mainly in Java right now.

  Read the article

• searching a mysql database

  - by Bill Parson

  currently i have a database of music that i have db'd in mysql, now i am writing a php frontend for it, and it will list out everything in a table, it works, but if i search "the beatles" it gives me 453 results(correct) however if i just search "beatles" it results in 0 rows, how would i go about making it able to search for something like that? heres my current line: $query2 = "SELECT * From `songs` WHERE `Artist` like '".$_REQUEST['q']."' OR `Album` like '".$_REQUEST['q']."' OR `Genre` like '".$_REQUEST['q']."' OR `Title` like '".$_REQUEST['q']."';";

  Read the article

• What is the difference between the Facade and Addapter Pattern?

  - by devoured elysium

  I've been reading both definitions and they seem quite the same. Could anyone point out what are their differences? Thanks

  Read the article

• Function for putting all database table to an array

  - by jasmine

  I have written a function to print database table to an array like this $db_array= Array( ID=>1, PARENTID =>1, TITLE => LIPSUM, TEXT =>LIPSUM ) My function is: function dbToArray($table) { $allArrays =array(); $query = mysql_query("SELECT * FROM $table"); $dbRow = mysql_fetch_array($query); for ($i=0; $i<count($dbRow) ; $i++) { $allArrays[$i] = $dbRow; } $txt .='<pre>'; $txt .= print_r($allArrays); $txt .= '</pre>'; return $txt; } Anything wrong in my function. Any help is appreciated about my problem. Thanks in advance

  Read the article

• same flash file (.swf) downloaded multiple times on a page

  - by Gunjan

  I have a page that has a table with each row corresponding to an audio file. The last cell in each row embeds a simple flash audio player. The problem is that the flash file for the player is being downloaded for each row separately and as soon as rows go beyond 40-50 it crashes the browser. I tried using different players (1pixelout, flash-mp3-player) and the problem is still there, so its not a player specific issue. Is there any way to cache the player so that it is only downloaded once?

  Read the article

• Events in Classes (VB.NET)

  - by Otaku

  I find that I write a lot of code within my classes to keep properties in sync with each other. I've read about Events in Classes, but have not been able to wrap my head around how to make them work for what I'm looking for. I could use some advice here. For example, in this one I always want to keep myColor up to date with any change whatsoever in any or all of the Red, Green or Blue properties. Class myColors Private Property Red As Byte Private Property Green As Byte Private Property Blue As Byte Private Property myColor As Color Sub New() myColor = Color.FromArgb(0, 0, 0) End Sub Sub ChangeRed(ByVal r As Byte) Red = r myColor = Color.FromArgb(Red, Green, Blue) End Sub Sub ChangeBlue(ByVal b As Byte) Blue = b myColor = Color.FromArgb(Red, Green, Blue) End Sub End Class If one or more of those changes, I want myColor to be updated. Easy enough as above, but is there a way to work with events that would automatically do this so I don't have to put myColor = Color.FromArgb(Red, Green, Blue) in every sub routine?

  Read the article

• Smartest way to import massive datasets into a Rails application?

  - by williamjones

  I've got multiple massive (multi gigabyte) datasets I need to import into a Rails app. The datasets are currently each in their own database on my development machine, and I need to read from them and create rows in tables in my Rails database based on the information they contain. The tables in my Rails database will not be exactly the same as the tables in the source databases. What's the smartest way to go about this? I was thinking migrations, but I'm not exactly sure how to connect the migration to the databases, and even if that is possible, is that going to be ridiculously slow?

  Read the article

• How can I define an empty array in a Perl construtor?

  - by Laimoncijus

  I am just beginner with Perl, so if it sounds stupid - sorry for that :) My problem is - I am trying to write a class, which has an empty array, defined in constructor of a class. So I am doing this like this: package MyClass; use strict; sub new { my ($C) = @_; my $self = { items => () }; bless $self, ref $C || $C; } sub get { return $_[0]->{items}; } 1; Later I am testing my class with simple script: use strict; use Data::Dumper; use MyClass; my $o = MyClass->new(); my @items = $o->get(); print "length = ", scalar(@items), "\n", Dumper(@items); And while running the script I get following: $ perl my_test.pl length = 1 $VAR1 = undef; Why am I doing wrong what causes that I get my items array filled with undef? Maybe someone could show me example how the class would need to be defined so I would not get any default values in my array?

  Read the article

• Question of using static_cast on "this" pointer in a derived object to base class

  - by Johnyy

  Hi, this is an example taken from Effective C++ 3ed, it says that if the static_cast is used this way, the base part of the object is copied, and the call is invoked from that part. I wanted to understand what is happening under the hood, will anyone help? class Window { // base class public: virtual void onResize() { } // base onResize impl }; class SpecialWindow: public Window { // derived class public: virtual void onResize() { // derived onResize impl; static_cast<Window>(*this).onResize(); // cast *this to Window, // then call its onResize; // this doesn't work! // do SpecialWindow- } // specific stuff };

  Read the article

• Proxy object references in MVC code

  - by krystan honour

  Hi there, I am just figuring out best practice with MVC now I have a project where we have chosen to use it in anger. My question is. If creating a list view which is bound to an IEnumerable is this bad practise? Would it be better to seperate the code generated by the WCF Service reference into a datastructure which essentially holds the same data but abstracts further from the service, meaning that the UI is totally unaware of the service implementation beneath. or do people just bind to the proxy object types and have done with it ? My personal feeling is to create an abstraction but this seems to violate the DRY principle.

  Read the article

• Access Codeigniter database functions from file

  - by Manny Calavera

  Hello. I am using a SWFupload script and I can't make a request from flash with mod_rewrite, I don't know why... I just need to point the Flash request to that file directly. This file runs an upload script that works ok but now I need to save some info to the database and I would like to know what should I write to have access from that file that is not called from the controller and does not extend the model in order to run a mysql query. Thanks.

  Read the article

< Previous Page | 344 345 346 347 348 349 350 351 352 353 354 355  | Next Page >