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  • loaderInfo null inside creationComplete handler function

    - by Thiago
    Hi, I've coded this small snippet to show what I'm not understanding: <?xml version="1.0" encoding="utf-8"?> <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" creationComplete="init()"> <mx:Script> public function init():void { txtName.text = this.loaderInfo.toString(); } </mx:Script> <mx:TextInput x="50" y="10" id="txtName"/> </mx:Application> I'm getting the following error: TypeError: Error #1009: Cannot access a property or method of a null object reference. at Teste/init()[C:\Lucas\flex\AppName\src\Teste.mxml:5] at Teste/___Teste_Application1_creationComplete()[C:\User\flex\CornetaRecorder\src\Teste.mxml:2] at flash.events::EventDispatcher/dispatchEventFunction() at flash.events::EventDispatcher/dispatchEvent() at mx.core::UIComponent/dispatchEvent()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\UIComponent.as:9298] at mx.core::UIComponent/set initialized()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\UIComponent.as:1169] at mx.managers::LayoutManager/doPhasedInstantiation()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\managers\LayoutManager.as:718] at Function/http://adobe.com/AS3/2006/builtin::apply() at mx.core::UIComponent/callLaterDispatcher2()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\UIComponent.as:8628] at mx.core::UIComponent/callLaterDispatcher()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\UIComponent.as:8568] Shouldn't I be able to read loaderInfo inside the creationComplete handler? I'm trying to pass a string from the html to my flash component, that's why I have to get loaderInfo working.

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  • Using a Scala symbol literal results in NoSuchMethod

    - by Benson
    I have recently begun using Scala. I've written a DSL in it which can be used to describe a processing pipeline in medici. In my DSL, I've made use of symbols to signify an anchor, which can be used to put a fork (or a tee, if you prefer) in the pipeline. Here's a small sample program that runs correctly: object Test extends PipelineBuilder { connector("TCP") / Map("tcpProtocol" -> new DirectProtocol()) "tcp://localhost:4858" --> "ByteToStringProcessor" --> Symbol("hello") "stdio://in?promptMessage=enter name:%20" --> Symbol("hello") Symbol("hello") --> "SayHello" / Map("prefix" -> "\n\t") --> "stdio://out" } For some reason, when I use a symbol literal in my program, I get a NoSuchMethod exception at runtime: java.lang.NoSuchMethodError: scala.Symbol.intern()Lscala/Symbol; at gov.pnnl.mif.scaladsl.Test$.<init>(Test.scala:7) at gov.pnnl.mif.scaladsl.Test$.<clinit>(Test.scala) at gov.pnnl.mif.scaladsl.Test.main(Test.scala) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at scala.tools.nsc.ObjectRunner$$anonfun$run$1.apply(ObjectRunner.scala:75) at scala.tools.nsc.ObjectRunner$.withContextClassLoader(ObjectRunner.scala:49) at scala.tools.nsc.ObjectRunner$.run(ObjectRunner.scala:74) at scala.tools.nsc.MainGenericRunner$.main(MainGenericRunner.scala:154) at scala.tools.nsc.MainGenericRunner.main(MainGenericRunner.scala) This happens regardless of how the symbol is used. Specifically, I've tried using the symbol in the pipeline, and in a simple println('foo) statement. The question: What could possibly cause a symbol literal's mere existence to cause a NoSuchMethodError? In my DSL I am using an implicit function which converts symbols to instances of the Anchor class, like so: implicit def makeAnchor(a: Symbol):Anchor = anchor(a) Sadly, my understanding of Scala is weak enough that I can't think of why that might be causing my NoSuchMethodError.

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  • Architecting iPhone Views - seeking help on a specific issue + general advice

    - by Ev
    Hi there, I am a web developer (rails, python) that is new to iPhone development. I've done some desktop development in the past within the MS environment (C#). I'm trying to build a really simple iPhone application and I am confused by the way that views work in general. If someone can provide advice for my particular problem, along with some resources where I can learn how to architect iPhone views in the future, that would be awesome. I feel like a lot of the Apple documentation that I've come across is too specific - I am lacking a fundamental understanding of how views work on the iPhone. My particular problem looks like this: I need one view that displays some downloaded text content. This is the view that shows when the app loads, and it is pretty straightforward. Then I need a settings area (I've already decided I don't want to use the iPhone settings area). The settings area main page will have some text fields on it. It will also have a 2-row grouped table. Each cell in that table will take you to another view which also has a grouped table used for multi-select. I suspect that I can reuse the same view for these two final "detailed setting" views. In summary: home page settings main page detailed setting 1 detailed setting 2 Any help and advice appreciated.

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  • trying to draw scaled UIImage in custom view, but nothing's rendering

    - by Ben Collins
    I've created a custom view class and right now just want to draw an image scaled to fit the view, given a UIImage. I tried just drawing the UIImage.CGImage, but as others have attested to on this site (and in the docs), that renders the image upside down. So, at the suggestion of an answer I found to another question, I'm trying to draw it directly, but nothing is rendering in the view and I'm not sure why. Here's my drawing code: - (void)drawRect:(CGRect)rect { // Drawing code [super drawRect:rect]; if (self.originalImage) { [self drawImage]; } } - (void) drawImage { if (CGSizeEqualToSize(originalImage.size, self.frame.size) == NO) { CGFloat scaleFactor = 1.0; CGFloat scaledWidth = 0.0; CGFloat scaledHeight = 0.0; CGPoint thumbPoint = CGPointMake(0.0, 0.0); CGFloat widthFactor = self.frame.size.width / originalImage.size.width; CGFloat heightFactor = self.frame.size.height / originalImage.size.height; if (widthFactor < heightFactor) { scaleFactor = widthFactor; } else { scaleFactor = heightFactor; } scaledWidth = originalImage.size.width * scaleFactor; scaledHeight = originalImage.size.height * scaleFactor; if (widthFactor < heightFactor) { thumbPoint.y = (self.frame.size.height - scaledHeight) * 0.5; } else if (widthFactor > heightFactor) { thumbPoint.x = (self.frame.size.width - scaledWidth) * 0.5; } UIGraphicsBeginImageContext(self.frame.size); CGRect thumbRect = CGRectZero; thumbRect.origin = thumbPoint; thumbRect.size.width = scaledWidth; thumbRect.size.height = scaledHeight; [originalImage drawInRect:thumbRect]; self.scaledImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); } else { self.scaledImage = originalImage; } } My understanding (after studying this a bit) is that the UIGraphicsBeginImageContext function creates an offscreen for me to draw into, so now how do I render that context on top of the original one?

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  • How does this Switch statement know which case to execute? (PHP/MySQL)

    - by ggfan
    Here is a code form a PHP+MySQL book I am reading and I am having trouble understanding this code. This code is about checking a file uploaded into a database. (Please excuse any spelling errors if any, I was typing it in) Q1: How does it know which case to echo? In the whole code, there is no mention of each case. Q2: Why do they skip case 5?! Or does it not matter which numbers you use(so I can have case 1, case 18, case 2?) if($_FILES['userfile']['error']>0) { echo 'Problem: '; switch($_FILES['userfile']['error']) { case 1: echo 'File exceeded upload_max_filesize'; break; case 2: echo 'File exceeded max_file_size'; break; case 3: echo 'File only partially uploaded'; break; case 4: echo 'No file uploaded'; break; case 6: echo 'Cannot upload file: no temp directory specified'; break; case 7: echo 'Upload failed: Cannot write to disk'; break; } exit; }

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  • CLR Stored Procedures

    - by Paul Hatcherian
    In an ASP.NET application, I have a small number of fairly complex, frequently used operations to execute against a database. In these operations, one or more of several tables needs updates or inserts based a logical evaluation of both input parameters and values of certain tables. I've maintained a separation of logic and data access, so the operation currently looks like this: Request received from client Business layer invokes data layer to retrieve data from database Business layer processes result and determines which operation to execute Business layer invokes appropriate data operation Response sent to client As you can see, the client is kept waiting while two separate requests are made to the database. In searching for a solution to this, I've found CLR Stored Procedures, but I'm not sure if I have the right idea about what they are useful for. I have written a replacement for the code above which especially places steps 2-4 in a CLR SP. My understanding is that the SP will be executed locally by SQL Server and result in only one call being made to the server. My initial benchmark tests show this is actually orders of magnitude slower than my original code, but I attribute that recompilation of the code I have not worked out yet and/or some flaw in my environment. My question is basically, is this the intended use of CLR SPs or am I missing something? I realize this is a bit of a compromise structurally, so if there's a better way to do it I'd love to hear it.

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  • diffie-hellman ssh keyxchange

    - by Chuck
    Hi, I've set out to make a primitive SSH client in C#; you might remember me from posts such as http://stackoverflow.com/questions/2872279/c-primitive-ssh-connection-lowlevel hehe. Anyway, things are great up until the time when I initiate a DH key exchange. I've compared the traffic when I establish a ssh connection (from openssh client to openssh server), to the traffic when my client connects to the same openssh server. OpenSSH client - OpenSSH server (S for server, C for client): S: SSH-2.0-OpenSSH_5.1p1 Debian-6ubuntu2\r (saying hello) C: SSH-2.0-OpenSSH_5.2\r (introducing myself) C: Key Exchange Init (0x14 = 20) S: Key Exchange Init C: Diffie-Hellman GEX Request (0x22 = 34) (with DH GEX min, number of bits and max) S: Diffie-Hellman Key Exchange Reply (with P, G, etc.) C: Diffie-Hellman GEX Init S: Diffie-Hellman GEX Reply My client - OpenSSH server: S: SSH-2.0-OpenSSH_5.1p1 Debian-6ubuntu2\r (saying hello) C: SSH-2.0-Some_Name\r (introducing myself) C: Key Exchange Init (0x14 = 20) S: Key Exchange Init C: Diffie-Hellman GEX Request (0x22 = 34) (with DH GEX min, number of bits and max) and then a bogus TCP packet as reply (probably the server connection has been terminated after/upon GEX Request. I have yet to use AES128 (which I think is the encryption chosen, but I'm not sure how to verify this...), and I'm still sending in a non-compressed format, looking to get the P, G etc. values to make the DH calculations. So where I'm stranded is: RFC 4419 page 3 http://www.ietf.org/rfc/rfc4419.txt I've send SSH_MSG_KEY_DH_GEX_REQUEST, but the server does not respond SSH_MSG_KEX_DH_GEX_GROUP. Can anyone give me a little advice on what I'm not understanding here? Does the server not understand my GEX request (due to it expecting encryption, or?)? Any help is very much appreciated, thanks :)

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  • Covariance and Contravariance type inference in C# 4.0

    - by devoured elysium
    When we define our interfaces in C# 4.0, we are allowed to mark each of the generic parameters as in or out. If we try to set a generic parameter as out and that'd lead to a problem, the compiler raises an error, not allowing us to do that. Question: If the compiler has ways of inferring what are valid uses for both covariance (out) and contravariance(in), why do we have to mark interfaces as such? Wouldn't it be enough to just let us define the interfaces as we always did, and when we tried to use them in our client code, raise an error if we tried to use them in an un-safe way? Example: interface MyInterface<out T> { T abracadabra(); } //works OK interface MyInterface2<in T> { T abracadabra(); } //compiler raises an error. //This makes me think that the compiler is cappable //of understanding what situations might generate //run-time problems and then prohibits them. Also, isn't it what Java does in the same situation? From what I recall, you just do something like IMyInterface<? extends whatever> myInterface; //covariance IMyInterface<? super whatever> myInterface2; //contravariance Or am I mixing things? Thanks

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  • What are the attack vectors for passwords sent over http?

    - by KevinM
    I am trying to convince a customer to pay for SSL for a web site that requires login. I want to make sure I correctly understand the major scenarios in which someone can see the passwords that are being sent. My understanding is that at any of the hops along the way can use a packet analyzer to view what is being sent. This seems to require that any hacker (or their malware/botnet) be on the same subnet as any of the hops the packet takes to arrive at its destination. Is that right? Assuming some flavor of this subnet requirement holds true, do I need to worry about all the hops or just the first one? The first one I can obviously worry about if they're on a public Wifi network since anyone could be listening in. Should I be worried about what's going on in subnets that packets will travel across outside this? I don't know a ton about network traffic, but I would assume it's flowing through data centers of major carriers and there's not a lot of juicy attack vectors there, but please correct me if I am wrong. Are there other vectors to be worried about outside of someone listening with a packet analyzer? I am a networking and security noob, so please feel free to set me straight if I am using the wrong terminology in any of this.

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  • Java Concurrency : Synchronized(this) => and this.wait() and this.notify()

    - by jens
    Hello Experts, I would appreciate your help in understand a "Concurrency Example" from: http://forums.sun.com/thread.jspa?threadID=735386 Qute Start: public synchronized void enqueue(T obj) { // do addition to internal list and then... this.notify(); } public synchronized T dequeue() { while (this.size()==0) { this.wait(); } return // something from the queue } Quote End: My Question is: Why is this code valid? = When I synchronize a method like "public synchronized" = then I synchronize on the "Instance of the Object == this". However in the example above: Calling "dequeue" I will get the "lock/monitor" on this Now I am in the dequeue method. As the list is zero, the calling thread will be "waited" From my understanding I have now a deadlock situation, as I will have no chance of ever enquing an object (from an nother thread), as the "dequeue" method is not yet finised and the dequeue "method" holds the lock on this: So I will never ever get the possibility to call "enequeue" as I will not get the "this" lock. Backround: I have exactly the same problem: I have some kind of connection pool (List of Connections) and need to block if all connections are checked. What is the correct way to synchronize the List to block, if size exceeds a limit or is zero? Thank you very much Jens

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  • Lightweight spinlocks built from GCC atomic operations?

    - by Thomas
    I'd like to minimize synchronization and write lock-free code when possible in a project of mine. When absolutely necessary I'd love to substitute light-weight spinlocks built from atomic operations for pthread and win32 mutex locks. My understanding is that these are system calls underneath and could cause a context switch (which may be unnecessary for very quick critical sections where simply spinning a few times would be preferable). The atomic operations I'm referring to are well documented here: http://gcc.gnu.org/onlinedocs/gcc-4.4.1/gcc/Atomic-Builtins.html Here is an example to illustrate what I'm talking about. Imagine a RB-tree with multiple readers and writers possible. RBTree::exists() is read-only and thread safe, RBTree::insert() would require exclusive access by a single writer (and no readers) to be safe. Some code: class IntSetTest { private: unsigned short lock; RBTree<int>* myset; public: // ... void add_number(int n) { // Aquire once locked==false (atomic) while (__sync_bool_compare_and_swap(&lock, 0, 0xffff) == false); // Perform a thread-unsafe operation on the set myset->insert(n); // Unlock (atomic) __sync_bool_compare_and_swap(&lock, 0xffff, 0); } bool check_number(int n) { // Increment once the lock is below 0xffff u16 savedlock = lock; while (savedlock == 0xffff || __sync_bool_compare_and_swap(&lock, savedlock, savedlock+1) == false) savedlock = lock; // Perform read-only operation bool exists = tree->exists(n); // Decrement savedlock = lock; while (__sync_bool_compare_and_swap(&lock, savedlock, savedlock-1) == false) savedlock = lock; return exists; } }; (lets assume it need not be exception-safe) Is this code indeed thread-safe? Are there any pros/cons to this idea? Any advice? Is the use of spinlocks like this a bad idea if the threads are not truly concurrent? Thanks in advance. ;)

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  • Javascript scope chain

    - by Geromey
    Hi, I am trying to optimize my program. I think I understand the basics of closure. I am confused about the scope chain though. I know that in general you want a low scope (to access variables quickly). Say I have the following object: var my_object = (function(){ //private variables var a_private = 0; return{ //public //public variables a_public : 1, //public methods some_public : function(){ debugger; alert(this.a_public); alert(a_private); }; }; })(); My understanding is that if I am in the some_public method I can access the private variables faster than the public ones. Is this correct? My confusion comes with the scope level of this. When the code is stopped at debugger, firebug shows the public variable inside the this keyword. The this word is not inside a scope level. How fast is accessing this? Right now I am storing any this.properties as another local variable to avoid accessing it multiple times. Thanks very much!

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  • using jquery (json) to get ajax database entries in wordpress - PHP not working

    - by Matt Facer
    I'm writing a plugin for my wordpress site and am having trouble understanding the jquery ajax requests. In a nutshell, I am trying to get some user meta data loaded when the page loads. So in my javascript file I have a line: $.getJSON("http://mysite.co.uk/wp-content/plugins/myplugin/ajax/ajax.php?action=test", function(json) { // do stuff }); So the above DOES get called, but it's the PHP code I'm having trouble with. In the file ajax.php, I am making a database call, but NONE of the usual class information is available. I've tried including the admin ajax page, various other pages from my own plugin (which does work).... not sure what else to do! The database call method works OK in my plugin code.. but I guess that the ajax.php file is outside the WP framework so that's why it's not working... but I don't know how to get it IN the framework!? I just need to use the $wpdb->get_results($sql); command to get my SQL. The error returned from firebug is that I am making a call to an undefined function. Thanks for any help... $.getJSON("http://www.offbeatattractions.co.uk/wp-content/plugins/wp-geo-extended/ajax/change_location.php?action=listpoints", function(json) { alert(json.Locations.length);

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  • UITableView and UITableCellView, how does this work with core plot ?

    - by Luc
    Hello, I'm very new to iPhone programming, and I'm currently following tutos to understand the whole thing. I've been able to do what I needed (retrive data from a JSON http server, parse them with YAJL and plot the data in core plot). I have done this in a "simple" view where I have added a UILayerHostingView as requested by core-plot. I am now trying to follow this tuto: http://blogs.remobjects.com/blogs/mh/2010/01/26/p973 but I am missing the first part regarding the views... My understanding is that I need to create a view with a UITableView first. Then add a UITableCellView to make the first cell be able to contain the graph ? Is this right ? Where does the method "(id)initWithStyle:(UITableViewCellStyle)style" come from ? For my needs, only the first cell needs to contain a graph, I will put some other info in the other cells. As for now, I have created a new GraphListViewController, in the corresponding view I have added a listview but I do not see any auto generated methods regading cell customisation ? Do I need to implements DataSource in this controller and manually add some customisation methods ? Do I need to add a UITagbleViewCell to this UITableViewTable within IB ? Hope I am not getting to confusing... Thanks a lot for your help, Best Regards, Luc

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  • Practical Scheme Programming

    - by Ixmatus
    It's been a few months since I've touched Scheme and decided to implement a command line income partitioner using Scheme. My initial implementation used plain recursion over the continuation, but I figured a continuation would be more appropriate to this type of program. I would appreciate it if anyone (more skilled with Scheme than I) could take a look at this and suggest improvements. I'm that the multiple (display... lines is an ideal opportunity to use a macro as well (I just haven't gotten to macros yet). (define (ab-income) (call/cc (lambda (cc) (let ((out (display "Income: ")) (income (string->number (read-line)))) (cond ((<= income 600) (display (format "Please enter an amount greater than $600.00~n~n")) (cc (ab-income))) (else (let ((bills (* (/ 30 100) income)) (taxes (* (/ 20 100) income)) (savings (* (/ 10 100) income)) (checking (* (/ 40 100) income))) (display (format "~nDeduct for bills:---------------------- $~a~n" (real->decimal-string bills 2))) (display (format "Deduct for taxes:---------------------- $~a~n" (real->decimal-string taxes 2))) (display (format "Deduct for savings:-------------------- $~a~n" (real->decimal-string savings 2))) (display (format "Remainder for checking:---------------- $~a~n" (real->decimal-string checking 2)))))))))) Invoking (ab-income) asks for input and if anything below 600 is provided it (from my understanding) returns (ab-income) at the current-continuation. My first implementation (as I said earlier) used plain-jane recursion. It wasn't bad at all either but I figured every return call to (ab-income) if the value was below 600 kept expanding the function. (please correct me if that apprehension is incorrect!)

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  • Is it possible to convert a 40-character SHA1 hash to a 20-character SHA1 hash?

    - by ewitch
    My problem is a bit hairy, and I may be asking the wrong questions, so please bear with me... I have a legacy MySQL database which stores the user passwords & salts for a membership system. Both of these values have been hashed using the Ruby framework - roughly like this: hashedsalt = Digest::SHA1.hexdigest("--#{Time.now.to_s}--#{login}--") hashedpassword = Digest::SHA1.hexdigest("#{hashedsalt}:#{password}") So both values are stored as 40-character strings (varchar(40)) in MySQL. Now I need to import all of these users into the ASP.NET membership framework for a new web site, which uses a SQL Server database. It is my understanding that the the way I have ASP.NET membership configured, the user passwords and salts are also stored in the membership database (in table aspnet_Membership) as SHA1 hashes, which are then Base64 encoded (see here for details) and stored as nvarchar(128) data. But from the length of the Base64 encoded strings that are stored (28 characters) it seems that the SHA1 hashes that ASP.NET membership generates are only 20 characters long, rather than 40. From some other reading I have been doing I am thinking this has to do with the number of bits per character/character set/encoding or something related. So is there some way to convert the 40-character SHA1 hashes to 20-character hashes which I can then transfer to the new ASP.NET membership data table? I'm pretty familiar with ASP.NET membership by now but I feel like I'm just missing this one piece. However, it may also be known that SHA1 in Ruby and SHA1 in .NET are incompatible, so I'm fighting a losing battle... Thanks in advance for any insight.

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  • GAE - Getting TypeError requiring class instance be passed to class's own method...

    - by Spencer Leland
    I'm really new to programming... I set up a class to give supporting information for Google's User API user object. I store this info in the datastore using db.model. When I call the okstatus method of my user_info class using this code: elif user_info.okstatus(user): self.response.out.write("user allowed") I get this error: unbound method okstatus() must be called with user_info instance as first argument (got User instance instead) Here is my user_info class. class user_info: def auth_ctrlr(self, user): if self.status(user) == status_allowed: return ("<a href=\"%s\">Sign Out</a>)" % (users.create_login_url("/"))) else: return ("<a href=\"%s\">Sign In or Get an Account</a>)" % (users.create_logout_url("/"))) def status(self, user): match = sub_user.gql(qu_by_user_id, user.user_id) return match.string_status def group(self, user): match = sub_user.gql(qu_by_user_id, user.user_id) grp = group_names.gql(qu_by_user_id, match.groupID) return grp def okstatus(self, user): match = self.status(user) if match == status_allowed: return True My understanding is that the argument "self" inside the method's calling arguments describes it as a child to the class. I've tried everything I can think of and can't find any related info online. Can someone please tell me what I'm doing wrong? Thanks

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  • "select * from table" vs "select colA,colB,etc from table" interesting behaviour in SqlServer2005

    - by kristof
    Apology for a lengthy post but I needed to post some code to illustrate the problem. Inspired by the question What is the reason not to use select * ? posted a few minutes ago, I decided to point out some observations of the select * behaviour that I noticed some time ago. So let's the code speak for itself: IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[starTest]') AND type in (N'U')) DROP TABLE [dbo].[starTest] CREATE TABLE [dbo].[starTest]( [id] [int] IDENTITY(1,1) NOT NULL, [A] [varchar](50) NULL, [B] [varchar](50) NULL, [C] [varchar](50) NULL ) ON [PRIMARY] GO insert into dbo.starTest(a,b,c) select 'a1','b1','c1' union all select 'a2','b2','c2' union all select 'a3','b3','c3' go IF EXISTS (SELECT * FROM sys.views WHERE object_id = OBJECT_ID(N'[dbo].[vStartest]')) DROP VIEW [dbo].[vStartest] go create view dbo.vStartest as select * from dbo.starTest go go IF EXISTS (SELECT * FROM sys.views WHERE object_id = OBJECT_ID(N'[dbo].[vExplicittest]')) DROP VIEW [dbo].[vExplicittest] go create view dbo.[vExplicittest] as select a,b,c from dbo.starTest go select a,b,c from dbo.vStartest select a,b,c from dbo.vExplicitTest IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[starTest]') AND type in (N'U')) DROP TABLE [dbo].[starTest] CREATE TABLE [dbo].[starTest]( [id] [int] IDENTITY(1,1) NOT NULL, [A] [varchar](50) NULL, [B] [varchar](50) NULL, [D] [varchar](50) NULL, [C] [varchar](50) NULL ) ON [PRIMARY] GO insert into dbo.starTest(a,b,d,c) select 'a1','b1','d1','c1' union all select 'a2','b2','d2','c2' union all select 'a3','b3','d3','c3' select a,b,c from dbo.vExplicittest select a,b,c from dbo.vStartest If you execute the following query and look at the results of last 2 select statements, the results that you will see will be as follows: select a,b,c from dbo.vExplicittest a1 b1 c1 a2 b2 c2 a3 b3 c3 select a,b,c from dbo.vStartest a1 b1 d1 a2 b2 d2 a3 b3 d3 As you can see in the results of select a,b,c from dbo.vStartest the data of column c has been replaced with the data from colum d. I believe that is related to the way the views are compiled, my understanding is that the columns are mapped by column indexes (1,2,3,4) as apposed to names. I though I would post it as a warning for people using select * in their sql and experiencing unexpected behaviour. Note: If you rebuild the view that uses select * each time after you modify the table it will work as expected

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  • My Zend Framework 'quoting' mess.

    - by tharkun
    I've got a probably very simple issue to which I can't find a satisfactory (subjectively seen) answer in the Zend Framework manual or elsewhere... There are so many ways how I can hand over my php variables to my sql queries that I lost the overview and probably I lack some understanding about quoting in general. Prepared Statements $sql = "SELECT this, that FROM table WHERE id = ? AND restriction = ?"; $stmt = $this->_db->query($sql, array($myId, $myValue)); $result = $stmt->fetchAll(); I understand that with this solution I don't need to quote anything because the db handles this for me. Querying Zend_Db_Table and _Row objects over the API $users = new Users(); a) $users->fetchRow('userID = ' . $userID); b) $users->fetchRow('userID = ' . $users->getAdapter()->quote($userID, 'INTEGER')); c) $users->fetchRow('userID = ?', $userID); d) $users->fetchRow('userID = ?', $users->getAdapter()->quote($userID, 'INTEGER')); Questions I understand that a) is not ok because it's not quoted at all. But what about the other versions, what's the best? Is c) being treated like a statement and automatically quoted or do I need to use d) when I use the ? identifier?

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  • C# Why can't I find Sum() of this HashSet. says "Arithmetic operation resulted in an overflow."

    - by user2332665
    I was trying to solve this problem projecteuler,problem125 this is my solution in python(just for understanding the logic) import math lim=10**8 found=set() for start in xrange(1,int(math.sqrt(lim))): sos = start*start for i in xrange(start+1,int(math.sqrt(lim))): sos += (i*i) if sos >= lim: break s=str(int(sos)) if s==s[::-1]: found.add(sos) print sum(found) the same code I wrote in C# is as follows using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace ConsoleApplication1 { class Program { public static bool isPalindrome(string s) { string temp = ""; for (int i=s.Length-1;i>=0;i-=1){temp+=s[i];} return (temp == s); } static void Main(string[] args) { int lim = Convert.ToInt32(Math.Pow(10,8)); var found = new HashSet<int>(); for (int start = 1; start < Math.Sqrt(lim); start += 1) { int s = start *start; for (int i = start + 1; start < Math.Sqrt(lim); i += 1) { s += i * i; if (s > lim) { break; } if (isPalindrome(s.ToString())) { found.Add(s); } } } Console.WriteLine(found.Sum()); } } } the code debugs fine until it gives an exception at Console.WriteLine(found.Sum()); (line31). Why can't I find Sum() of the set found

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  • Core Data - Entity Relationships Not Working as expected

    - by slimms
    I have set up my data model in xcode like so EntityA AttA1 AttA2 EntityB AttB1 AttB2 AttB3 I then set up the relationships EntityA Name: rlpToEntityB Destination: EntityB Inverse: rlpToEntityA To Many: Checked EntityB Name: rlpToEntityA Destination: EntityA Inverse: rlpToEntityB To Many: UnChecked i.e. relationship between the two where Each one of EntityA can have many EntityB's It is my understanding that if i fetch a subset of EntityB's I can then retrieve the values for the related EntityA's. I have this working so that i can retrieve the EntityB values using NSManagedObject *objMO = [fetchedResultsController objectAtIndexPath:indexPath]; strValueFromEntityB = [objMO valueForKey:@"AttB1"]; However, if I try to retrieve a related value from EntityA by doing the following strValueFromEntityA = [objMO valueForKey:@"AttA1"]; I get the error "The entity EntityB is not Key value coding-compliant for the key Atta1" Not surprisingly i suppose if i switch things around to fetch from EntityA i cannot access attributes of EntityB So it appears the defined relationshipare being ignored. Can anyone spot what i am doing wrong? I confess im very new to iPhone programming and especially to Core Data so please go easy on me and provide verbose explanations or point me in the direction a specific resource. I have downloaded the apple sample apps (Core Data Books, Top Songs and recipes) but I still can't work this out. Thanks in advance, Nev.

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  • What is the relationship between Turing Machine & Modern Computer ?

    - by smwikipedia
    I heard a lot that modern computers are based on Turing machine. I just cannot build a bridge from a conceptual Turing Machine to a real modern computer. Could someone help me build this bridge? Below is my current understanding. I think the computer is a big general-purpose Turing machine. Each program we write is a small specific-purpose Turing machine. The classical Turing machine do its job based on the input and its current state inside and so do our programs. Let's take a running program (a process) as an example. We know that in the process's address space, there's areas for stack, heap, and code. A classical Turing machine doesn't have the ability to remember many things, so we borrow the concept of stack from the push-down automaton. The heap and stack areas contains the state of our specific-purpose Turing machine (our program). The code area represents the logic of this small Turing machine. And various I/O devices supply input to this Turing machine.

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  • Google's Oauth for Installed apps vs. Oauth for Web Apps

    - by burgerguy
    So I'm having trouble understanding something... If you do Oauth for Web Apps, you register your site with a callback URL and get a unique consumer secret key. But once you've obtained an Oauth for Web Apps token, you don't have to generate Oauth calls to the google server from your registered domain. I regularly use my key and token from scripts running via an apache server at localhost on my laptop and Google never says "you're not sending this request from the registered domain." It just sends me the data. Now, as I understand it, if you do Oauth for Installed Apps, you use "anonymous" instead of a secret key you got from Google. I've been thinking of just using the OAuth for Web Apps auth method, then passing that token to an installed app that has my secret code embedded in its innards. The worry is that the code could be discovered by bad people. But what's more secure... making them work for the secret code or letting them default to anonymous? What really goes bad if the "secret" is discovered when the alternative is using "anonymous" as the secret?

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  • SQL Server Clustered Index: (Physical) Data Page Order

    - by scherand
    I am struggling understanding what a clustered index in SQL Server 2005 is. I read the MSDN article Clustered Index Structures (among other things) but I am still unsure if I understand it correctly. The (main) question is: what happens if I insert a row (with a "low" key) into a table with a clustered index? The above mentioned MSDN article states: The pages in the data chain and the rows in them are ordered on the value of the clustered index key. And Using Clustered Indexes for example states: For example, if a record is added to the table that is close to the beginning of the sequentially ordered list, any records in the table after that record will need to shift to allow the record to be inserted. Does this mean that if I insert a row with a very "low" key into a table that already contains a gazillion rows literally all rows are physically shifted on disk? I cannot believe that. This would take ages, no? Or is it rather (as I suspect) that there are two scenarios depending on how "full" the first data page is. A) If the page has enough free space to accommodate the record it is placed into the existing data page and data might be (physically) reordered within that page. B) If the page does not have enough free space for the record a new data page would be created (anywhere on the disk!) and "linked" to the front of the leaf level of the B-Tree? This would then mean the "physical order" of the data is restricted to the "page level" (i.e. within a data page) but not to the pages residing on consecutive blocks on the physical hard drive. The data pages are then just linked together in the correct order. Or formulated in an alternative way: if SQL Server needs to read the first N rows of a table that has a clustered index it can read data pages sequentially (following the links) but these pages are not (necessarily) block wise in sequence on disk (so the disk head has to move "randomly"). How close am I? :)

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  • Getter and Setter vs. Builder strategy

    - by Extrakun
    I was reading a JavaWorld's article on Getter and Setter where the basic premise is that getters expose internal content of an object, hence tightening coupling, and go on to provide examples using builder objects. I was rather leery of abolishing getter/setter but on second reading of the article, see to quite like the idea. However, sometimes I just need one cruical element of an entity class, such as the user's id and writing one whole class just to extract that cruical element seems like overkill. It also implies that for different view, a different type of importer/exporter must be implemented (or the whole data of the class to be exported out, thus resulting in waste). Usually I tend towards filtering the result of a getter - for example, if I need to output the price of a product in different currency, I would code it as: return CurrencyOutput::convertTo($product->price(), 'USD'); This is with the understanding that the raw output of a getter is not necessary the final result to be pushed onto a screen or a database. Is getter/setter really as bad as it is protrayed to be? When should one adopt a builder strategy, or a 'get the result and filter it' approach? How do you avoid having a class needing to know about every other objects if you are not using getter/setter?

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