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  • Entity Framework Validation & usage

    - by kmsellers
    I'm aware there is an AssociationChanged event, however, this event fires after the association is made. There is no AssociationChanging event. So, if I want to throw an exception for some validation reason, how do I do this and get back to my original value? Also, I would like to default values for my entity based on information from other entities but do this only when I know the entitiy is instanced for insertion into the database. How do I tell the difference between that and the object getting instanced because it is about to be populated based on existing data? Am I supposed to know? Is that considiered business logic that should be outside of my entity business logic? If that's the case, then should I be designing controller classes to wrap all these entities? My concern is that if I deliver back an entity, I want the client to get access to the properties, but I want to retain tight control over validations on how they are set, defaulted, etc. Every example I've seen references context, which is outside of my enity partial class validation, right? BTW, I looked at the EFPocoAdapter and for the life of me cannot determine how to populate lists of from within my POCO class... anyone know how I get to the context from a EFPoco Class?

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  • how would you like computer science classes to be taught?

    - by aaa
    hello I am a graduate student now, and hopefully someday I will teach. my interests are C++, Python, embedded languages, and scientific computing. Meanwhile I daydream about how I would teach. I was not quite happy with my undergraduate university as I found many computer science classes lacking. so I would like to ask you, if you were a student, how would you like your computer science classes to be taught? I understand it is a very subjective question, but nevertheless I think it's important to know what people want. Some specific points I am interested in: should computer languages be taught explicitly, or should students be required to pick up language on their own? what is better for learning, tests, projects, some sort of take-home exam? how do you think classtime should be used? theory, introduction, explanations, etc.? do you think the group projects are important? how much about computer architecture do you want to learn in computer science class, not necessarily assembler class. should particular operating system/editor be mandated or encouraged? Thanks thank you for your comments. Question has been closed because it is a discussion question rather than Q&A. If you know appropriate website for discussions of such sort with low noise ratio, please let me know.

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  • IE browser script to determine which (if any) ActiveX control will handle specific mime type

    - by Jay13
    I'm trying to figure out in an IE script (javascript or vbscript) which ActiveX control will handle a specific mime type, "image/tiff" in this case. This is easy to do in other browsers that use plugins with; navigator.mimeTypes["image/tiff"].enabledPlugin.name which would return something like QuickTime Plug-in X.X.X I've found plenty of examples to tell if a specific plugin is loaded but since there are several plugins available that can handle tiff images I need to know which, if any, is registered to handle this mime type. The problem I'm trying to deal with is that QuickTime always wants to register itself as the default tiff viewer but it does a terrible job of it resulting in lots of support calls. Unfortunately, simply detecting that QuickTime is installed isn't good enough since the user may also have another tiff viewer installed (like Alternatiff) as the default tiff viewer or the user may have configured QuickTime to not be the default viewer for tiff images so the browser could be using a helper app to display the image instead. Not meaning to be difficult but before anyone suggests reengineering workarounds; yes I know I could force the user to use a specific ActiveX viewer in IE or to use a Java tiff viewer but I'd rather let them use a viewer of their choice rather than forcing them to install a viewer of my choosing, especially since their viewer may be a helper app that loads the tiff image into a business workflow within their office yes I know there are other image formats that I could use but tiff is the defacto standard for document imaging and that's what the vast majority of these users prefer to use. The problem isn't the image format, it's that QuickTime just doesn't cut it as a tiff viewer Thanks in advance for any suggestions or solutions...

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  • What is the way to go to fake my database layer in a unit test?

    - by Michel
    Hi, i have a question about unit testing. say i have a controller with one create method which puts a new customer in the database: //code a bit shortened public actionresult Create(Formcollection formcollection){ client c = nwe client(); c.Name = formcollection["name"]; ClientService.Save(c); { Clientservice would call a datalayer object and save it in the database. What i do now is create a database testscript and set my database in a know condition before testing. So when i test this method in the unit test, i know that there must be one more client in the database, and what it's name is. In short: ClientController cc = new ClientController(); cc.Create(new FormCollection (){name="John"}); //i know i had 10 clients before assert.areEqual(11, ClientService.GetNumberOfClients()); //the last inserted one is John assert.areEqual("John", ClientService.GetAllClients()[10].Name); So i've read that unit testing should not be hitting the database, i've setup an IOC for the database classes, but then what? I can create a fake database class, and make it do nothing. But then ofcourse my assertions will not work because if i say GetNumberOfClients() it will alwasy return X because it has no interaction with the fake database class used in the Create Method. I can also create a List of Clients in the fake database class, but as there will be two different instance created (one in the controller action and one in the unit test), they will have no interaction. What is the way to make this unit test work without a database?

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  • How to Detect in Windows Registry if user has .Net Framework installed?

    - by Sarah Weinberger
    How do I detect in the Windows Registry if a user has .Net Framework installed? I am not looking for a .Net based solution, as the query is from InnoSetup. I know from reading another post here on Stack Overflow that .Net Framework is an inplace upgrade to 4.0. I already know how to check if a user has version 4.0 installed on the system, namely by checking the following: function FindFramework(): Boolean; var bVer4x0: Boolean; bVer4x0Client: Boolean; bVer4x0Full: Boolean; bSuccess: Boolean; iInstalled: Cardinal; begin Result := False; bVer4x0Client := False; bVer4x0Full := False; bVer4x0 := RegKeyExists(HKLM, 'SOFTWARE\Microsoft\.NETFramework\policy\v4.0'); bSuccess := RegQueryDWordValue(HKLM, 'Software\Microsoft\NET Framework Setup\NDP\v4 \Client', 'Install', iInstalled); if (1 = iInstalled) AND (True = bSuccess) then bVer4x0Client := True; bSuccess := RegQueryDWordValue(HKLM, 'Software\Microsoft\NET Framework Setup\NDP\v4 \Full', 'Install', iInstalled); if (1 = iInstalled) AND (True = bSuccess) then bVer4x0Full := True; if (True = bVer4x0Full) then begin Result := True; end; end; I checked the registry and there is no v4.5 folder, which makes sense if .Net Framework 4.5 is an inplace upgrade. Still, the Control Panel Programs and Features includes the listing. I know that probably "issuing dotNetFx45_Full_setup.exe /q" will have no bad effect if installing on a system that already has version 4.5, but I still would like to not install the upgrade if the upgrade already exists, faster and less problems.

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  • New Rails deployment half working...not sure why?

    - by Meltemi
    I'm in the final stages of going round trip through the entire Rails cycle: development - test - production (on an external server). I'm very close...but seeing some errors with the production version and don't know enough about Rails' "magic" to troubleshoot it yet... all seems well and I can load my app by going to www.mydomain.com/rails and it seems to work...I can interact with my app and create new objects in my database. However, when I go to www.mydomain.com/rails/ (difference is the trailing slash) i get a webpage that just says "Index from public" on it?!? I don't know where that's coming from? index.html is long removed from public. this may or may not be related to why I can't access, say, the first record in one of my classes by calling its controller like so: www.mydomain.com/rails/mycontroller/1 . and yes, there are records in the database. anyway, something's askew. it works fine on development box. but, only half working on production server. anyone know what might be causing this? this app is running on the server box (not development) Installed Passenger on server to serve app via Apache modified my httpd.conf with Passenger's stuff (headache but finally got it to respond) loaded schema into the production database: rake db:schema:load RAILS_ENV=production

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  • ArrayAccess multidimensional (un)set?

    - by anomareh
    I have a class implementing ArrayAccess and I'm trying to get it to work with a multidimensional array. exists and get work. set and unset are giving me a problem though. class ArrayTest implements ArrayAccess { private $_arr = array( 'test' => array( 'bar' => 1, 'baz' => 2 ) ); public function offsetExists($name) { return isset($this->_arr[$name]); } public function offsetSet($name, $value) { $this->_arr[$name] = $value; } public function offsetGet($name) { return $this->_arr[$name]; } public function offsetUnset($name) { unset($this->_arr[$name]); } } $arrTest = new ArrayTest(); isset($arrTest['test']['bar']); // Returns TRUE echo $arrTest['test']['baz']; // Echo's 2 unset($arrTest['test']['bar']; // Error $arrTest['test']['bar'] = 5; // Error I know $_arr could just be made public so you could access it directly, but for my implementation it's not desired and is private. The last 2 lines throw an error: Notice: Indirect modification of overloaded element. I know ArrayAccess just generally doesn't work with multidimensional arrays, but is there anyway around this or any somewhat clean implementation that will allow the desired functionality? The best idea I could come up with is using a character as a separator and testing for it in set and unset and acting accordingly. Though this gets really ugly really fast if you're dealing with a variable depth. Does anyone know why exists and get work so as to maybe copy over the functionality? Thanks for any help anyone can offer.

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  • JavaScript: Double script tags in Google Analytics tracking code

    - by Tom
    This is more a curiosity question than anything else... Google instructs to add the analytics tracking code as follows: <script type="text/javascript"> var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www."); document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E")); </script> <script type="text/javascript"> try{ var pageTracker = _gat._getTracker("UA-xxxxxx-x"); pageTracker._trackPageview(); } catch(err) {} </script> I'm wondering some JS guru here could tell me why they're separating it into two script tags instead of sticking it all inside one. I know that the top part could be put in the header and the bottom part just before body tag to ensure the page loaded before it's tracked, but I'm wondering if there's something more to it. Anyone who'd know that would likely know how to separate the code into two tags anyway. I'm only asking as this is coming from the Goog and is being used by millions of sites... Thanks

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  • Given 4 objects, how to figure out whether exactly 2 have a certain property

    - by Cocorico
    Hi guys! I have another question on how to make most elegant solution to this problem, since I cannot afford to go to computer school right so my actual "pure programming" CS knowledge is not perfect or great. This is basically an algorhythm problem (someone please correct me if I am using that wrong, since I don't want to keep saying them and embarass myself) I have 4 objects. Each of them has an species property that can either be a dog, cat, pig or monkey. So a sample situation could be: object1.species=pig object2.species=cat object3.species=pig object4.species=dog Now, if I want to figure out if all 4 are the same species, I know I could just say: if ( (object1.species==object2.species) && (object2.species==object3.species) && (object3.species==object4.species) ) { // They are all the same animal (don't care WHICH animal they are) } But that isn't so elegant right? And if I suddenly want to know if EXACTLY 3 or 2 of them are the same species (don't care WHICH species it is though), suddenly I'm in spaghetti code. I am using Objective C although I don't know if that matters really, since the most elegant solution to this is I assume the same in all languages conceptually? Anyone got good idea? Thanks!!

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  • Unboxing to unknown type

    - by Robert
    I'm trying to figure out syntax that supports unboxing an integral type (short/int/long) to its intrinsic type, when the type itself is unknown. Here is a completely contrived example that demonstrates the concept: // Just a simple container that returns values as objects struct DataStruct { public short ShortVale; public int IntValue; public long LongValue; public object GetBoxedShortValue() { return LongValue; } public object GetBoxedIntValue() { return LongValue; } public object GetBoxedLongValue() { return LongValue; } } static void Main( string[] args ) { DataStruct data; // Initialize data - any value will do data.LongValue = data.IntValue = data.ShortVale = 42; DataStruct newData; // This works if you know the type you are expecting! newData.ShortVale = (short)data.GetBoxedShortValue(); newData.IntValue = (int)data.GetBoxedIntValue(); newData.LongValue = (long)data.GetBoxedLongValue(); // But what about when you don't know? newData.ShortVale = data.GetBoxedShortValue(); // error newData.IntValue = data.GetBoxedIntValue(); // error newData.LongValue = data.GetBoxedLongValue(); // error } In each case, the integral types are consistent, so there should be some form of syntax that says "the object contains a simple type of X, return that as X (even though I don't know what X is)". Because the objects ultimately come from the same source, there really can't be a mismatch (short != long). I apologize for the contrived example, it seemed like the best way to demonstrate the syntax. Thanks.

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  • File Enumeration with ANT

    - by 1ndivisible
    I feel like I'm missing something obvious at the moment. I want to collect a set of dirs / files together in ANT. I know I can do it using a fileset with an optional patternset inside it, but that involves searching for files based a specific criterior - filetype, name etc. I already know the paths to the files I want to collect. I have n properties which reference these paths. I want a way to collect these paths in a fileset, though I cannot find a way to do it. This represents what I want to achieve (I know it isn't valid code, but hopefully it will describe what I mean): <fileset> <path>${src.dir}</path> <path>${test.dir}</path> <path>${third.party.src.dir}</path> <path>${bin.dir}</path> <path>${docs.build.txt}</path> </fileset>

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  • SVN Serve, Missing a Directory

    - by Ryan Smith
    I'm sure this is an asinine question, and I blame myself for not fully understanding how the SVNSERVE process works. I have an SVN repo, but it needs to be moved to a server within a clients cloud. I did this a while back and ran into the issue of the SVNSERVE.exe process not getting set to the right directory. I have the SVNSERVE.exe process running as a windows service and pointing to the right directory. There are two other repos there that are serving out fine in the same directory. I copied out the new directory just like I did with the others, but I'm getting the error "No repository found". I thought that SVNSERVE just looked at that directory and served out the repositories that were there, but I have had a hard time finding more information about that. I thought it was a Windows permission problem, but I set the whole folder to be full control to EVERYONE, so that's not it. I feel horrible I didn't fully understand this problem the first time I fought it, but it's late on a Sunday night and clients are yelling. Anyone know what I'm missing? Thanks. EDIT: It's specific to the repository. I tested the same process with some of the other repos we have on our server and when I copied them up, they worked just as expected. This bug is breaking me and I wish I could provide more details, but that's all I know. I'm going to try to do an SVN Dump instead of an XCopy and see how that goes. I'll let you know.

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  • displaying a saved buffer in OpenGL ES

    - by Adam
    Hi everyone, So basically I have a screenshot that I've saved that I want to later display on the screen. I've saved it with: glReadPixels(0, 0, self.bounds.size.width, self.bounds.size.height, GL_RGBA, GL_UNSIGNED_BYTE, savedBuffer); And later I'm trying to write it to the screen with: GLuint RenderedTex; glGenTextures(1, &RenderedTex); glEnable(GL_TEXTURE_2D); glBindTexture(GL_TEXTURE_2D, RenderedTex); glTexImage2D (GL_TEXTURE_2D, 0, GL_RGBA, self.bounds.size.width, self.bounds.size.height, 0, GL_RGBA, GL_UNSIGNED_BYTE, savedBuffer); glDisable(GL_TEXTURE_2D); I'm pretty new to OpenGL so I don't know if I'm doing things right... actually I know I'm not, because nothing shows up. Also not sure how to dispose of the texture when I'm done with it. Anyone know the correct way to do this? Edit: I think I might be having a problem loading the texture because it's not a power of 2, it's 320x480... also, I think this code is just loading the texture, but not drawing it, I'd need a call to glDrawArrays(GL_TRIANGLE_STRIP, 0, 4) in there somewhere...

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  • Adapter for circle page indicator in android

    - by Charles LAU
    I am currently working on an android application which have multiple pages. I am trying to use Circle page indicator to allow users view multiple pages by flipping over the screen. Each page has seperate XML file for the view and each page has a button which is bind to a java method in the Activity. I would like to know how to initalise all the buttons in the Activity for multiple pages. Because at the moment, I can only initalise the button for the first page of the views. I cannot initalise the button for second and third page. Does anyone know how to achieve this. I have placed all the jobs to be done for all the buttons in a single activity. I am currently using this indicator : http://viewpagerindicator.com/ Here is my adapter for the circle page indicator: @Override public Object instantiateItem(View collection, int position) { inflater = (LayoutInflater) collection.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE); int resid = 0; //View v = null;// inflater.inflate( R.layout.gaugescreen, (ViewPager)collection, false ); switch( position ) { case 0: resid = R.layout.gaugescreen; break; case 1: resid= R.layout.liveworkoutstatisticsscreen; break; case 2: resid = R.layout.mapscreen; break; default: resid = R.layout.gaugescreen; break; } View view = inflater.inflate(resid, null); ((ViewPager) collection).addView(view,0); return view; } Does anyone know how to achieve this? Thanks for any help in advance

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  • Global Temporary Table "On commit delete rows" functionality discrepancy.

    - by TomatoSandwich
    I have a global temporary table. I called my GTT, for that was it's initials. My GTT never hurt anyone, and did everything I bade of it. I asked my GTT to delete rows on commit. This is a valid function in the creation script of my GTT in oracle. I wanted to be able to have different users see GTT with their own data, and not the data of other people's sessions. 'Delete rows on commit' worked perfectly in our test environment. GTT and I were happy. But then, I deployed GTT as part of an update to functionality to a client's database. The database doesn't like to play well with GTT. GTT called me up all upset and worried, because it wasn't holding any data any more, and didn't know why. GTT told me that if someone did: insert into my_GTT (description) values ('Happy happy joy joy') he would sing-song back: 1 row inserted. However, if the same person tried select * from my_GTT; GTT didn't know what to do, and he replied 0 rows returned. GTT was upset that he didn't know what his playmate had inserted. Please, Stackoverflow, why would GTT forget what was placed into him? He can remember perfectly well at home, but out in the cold harsh world, he just gets so scared. :(

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  • Is there a mechanism to distribute an app with its own JRE?

    - by user179997
    These fine folks are my users: http://www.youtube.com/watch?v=o4MwTvtyrUQ If you don't want to enjoy the video here is the gist: my users can't tell between a file and a folder, between a browser and a web site. I need to create a Java web app (Tomcat or Jetty) and deploy it in as many of their computers, Windows and Mac. The question is: Is there a mechanism to distribute an app with its own JRE? (in the Tcl world there are starpacks and starkits, in the Python world there's py2exe and others, that's the idea). And also, is it legal? I know the VM is open source but I'm not clear about the libraries, and I know about GNU Classpath but I don't know if all the packages are there. I don't want to depend on the installed JRE or on the user having enough privileges to install one. On the Mac I don't want to depend on Apple (I had to switch from Tiger to Snow Leopard just to have Java 1.6, I can't put my users in that position) Any info greatly appreciated. Thanks! jb edit: I'm wondering if I can just paste the JRE folder under my app folder. Is that allowed?

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  • Is XMLReader a SAX parser, a DOM parser, or neither?

    - by Renesis
    I am testing various methods to read (possibly large, and very often) XML configuration files in PHP. No writing is ever needed. I have two successful implementations, one using SimpleXML (which I know is a DOM parser) and one using XMLReader. I know that a DOM reader must read the whole tree and therefore uses more memory. My tests reflect that. I also know that A SAX parser is an "event-based" parser that uses less memory because it reads each node from the stream without checking what is next. XMLReader also reads from a stream with the cursor providing data about the node it is currently at. So, it definitely sounds like XMLReader (http://us2.php.net/xmlreader) is not a DOM parser, but my question is, is it a SAX parser, or something else? It seems like XMLReader behaves the way a SAX parser does but does not throw the events themselves (in other words, can you construct a SAX parser with XMLReader?) If it is something else, does the classification it's in have a name?

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  • Locating SSL certificate, key and CA on server

    - by jovan
    Disclaimer: you don't need to know Node to answer this question but it would help. I have a Node server and I need to make it work with HTTPS. As I researched around the internet, I found that I have to do something like this: var fs = require('fs'); var credentials = { key: fs.readFileSync('path/to/ssl/private-key'), cert: fs.readFileSync('path/to/ssl/cert'), ca: fs.readFileSync('path/to/something/called/CA') }; var app = require('https').createServer(credentials, handler); I have several problems with this. First off, all the examples I found use completely different approaches. Some link to .pem files for both the certificate and key. I don't know what pem files are but I know my certificate is .crt and my key is .key. Some start off at the root folder and some seem to just have these .pem files in the application directory. I don't. Some use the ca thing too and some don't. This CA is supposed to be my domain's CA bundle according to some articles - but none explain where to find this file. In the ssl directory on my server I have one .crt file in the certs directory and one .key file in the keys directory, in addition to an empty csrs directory and an ssl.db file. So, where do I find these 3 files (key, cert, ca) and how do I link to them correctly?

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  • How do I retrieve an automated report and save it to a database?

    - by Mason Wheeler
    I've got a web server that will take scripts in Python, PHP or Perl. I don't know much about any of those languages, but of the three, Python seems the least scary. It has a MySql database set up, and I know enough SQL to manage it and write queries for it. I also have a program that I want to add automated error reporting to. Something goes wrong, it sends a bug report to my server. What I don't know how to do is write a Python script that will sit on the web server and, when my program sends in a bug report, do the following: Receive the bug report. Parse it out into sections. Insert it into the database. Have the server send me an email. From what little I understand, this seems like it shouldn't be too difficult if I only knew what I was doing. Could someone point me to a site that explains the basic principles I'd need to create a script like this?

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  • Vertex Buffers in opengl

    - by JB
    I'm making a small 3d graphics game/demo for personal learning. I know d3d9 and quite a bit about d3d11 but little about opengl at the moment so I'm intending to abstract out the actual rendering of the graphics so that my scene graph and everything "above" it needs to know little about how to actually draw the graphics. I intend to make it work with d3d9 then add d3d11 support and finally opengl support. Just as a learning exercise to learn about 3d graphics and abstraction. I don't know much about opengl at this point though, and don't want my abstract interface to expose anything that isn't simple to implement in opengl. Specifically I'm looking at vertex buffers. In d3d they are essentially an array of structures, but looking at the opengl interface the equivalent seems to be vertex arrays. However these seem to be organised rather differently where you need a separate array for vertices, one for normals, one for texture coordinates etc and set the with glVertexPointer, glTexCoordPointer etc. I was hoping to be able to implement a VertexBuffer interface much like the the directx one but it looks like in d3d you have an array of structures and in opengl you need a separate array for each element which makes finding a common abstraction quite hard to make efficient. Is there any way to use opengl in a similar way to directx? Or any suggestions on how to come up with a higher level abstraction that will work efficiently with both systems?

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  • Joining Tables Based on Foreign Keys

    - by maestrojed
    I have a table that has a lot of fields that are foreign keys referencing a related table. I am writing a script in PHP that will do the db queries. When I query this table for its data I need to know the values associated with these keys not the key. How do most people go about this? A 101 way to do this would be to query this table for its data including the foreign keys and then query the related tables to get each key's value. This could be a lot of queries (~10). Question 1: I think I could write 1 query with a bunch of joins. Would that be better? This approach also requires the querying script to know which table fields are foreign keys. Since I have many tables like this but all with different fields, this means writing nice generic functions is hard. MySQL InnoDB tables allow for foreign constraints. I know the database has these set up correctly. Question 2: What about the idea of querying the table and identifying what the constraints are and then matching them up using whatever process I decide on from Question 1. I like this idea but never see it being used in code. Makes me think its not a good idea for some reason. I would use something like SHOW CREATE TABLE tbl_name; to find what constraints/relationships exist for that table. Thank you for any suggestions or advice.

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  • Varchar columns: Nullable or not.

    - by NYSystemsAnalyst
    The database development standards in our organization state the varchar fields should not allow null values. They should have a default value of an empty string (""). I know this makes querying and concatenation easier, but today, one of my coworkers questioned me about why that standard only existed for varchar types an not other datatypes (int, datetime, etc). I would like to know if others consider this to be a valid, defensible standard, or if varchar should be treated the same as fields of other data types? I believe this standard is valid for the following reason: I believe that an empty string and null values, though technically different, are conceptually the same. An empty, zero length string is a string that does not exist. It has no value. However, a numeric value of 0 is not the same as NULL. For example, if a field called OutstandingBalance has a value of 0, it means there are $0.00 remaining. However, if the same field is NULL, that means the value is unknown. On the other hand, a field called CustomerName with a value of "" is basically the same as a value of NULL because both represent the non-existence of the name. I read somewhere that an analogy for an empty string vs. NULL is that of a blank CD vs. no CD. However, I believe this to be a false analogy because a blank CD still phyically exists and still has physical data space that does not have any meaningful data written to it. Basically, I believe a blank CD is the equivalent of a string of blank spaces (" "), not an empty string. Therefore, I believe a string of blank spaces to be an actual value separate from NULL, but an empty string to be the absense of value conceptually equivalent to NULL. Please let me know if my beliefs regarding variable length strings are valid, or please enlighten me if they are not. I have read several blogs / arguments regarding this subject, but still do not see a true conceptual difference between NULLs and empty strings.

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  • How to efficiently convert String, integer, double, datetime to binary and vica versa?

    - by Ben
    Hi, I'm quite new to C# (I'm using .NET 4.0) so please bear with me. I need to save some object properties (their properties are int, double, String, boolean, datetime) to a file. But I want to encrypt the files using my own encryption, so I can't use FileStream to convert to binary. Also I don't want to use object serialization, because of performance issues. The idea is simple, first I need to somehow convert objects (their properties) to binary (array), then encrypt (some sort of xor) the array and append it to the end of the file. When reading first decrypt the array and then somehow convert the binary array back to object properties (from which I'll generate objects). I know (roughly =) ) how to convert these things by hand and I could code it, but it would be useless (too slow). I think the best way would be just to get properties' representation in memory and save that. But I don't know how to do it using C# (maybe using pointers?). Also I though about using MemoryStream but again I think it would be inefficient. I am thinking about class Converter, but it does not support toByte(datetime) (documentation says it always throws exception). For converting back I think the only options is class Converter. Note: I know the structure of objects and they will not change, also the maximum String length is also known. Thank you for all your ideas and time. EDIT: I will be storing only parts of objects, in some cases also parts of different objects (a couple of properties from one object type and a couple from another), thus I think that serialization is not an option for me.

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  • Redirecting users after destroy

    - by mathee
    I have 3 models: Questions, Answers, and Profiles (I know, it should be called "Users"). When you view a question Q, I query the database for the answers to Q. (They are linked by id.) In the view, the current user has the option to delete his answer by clicking on the destroy link displayed next to his answer: %table %tr %td Answers: - @answers.each do |a| %tr %td - @provider = Profile.find(a.provider) %i #{h @provider.username} said: %br #{h a.description} %td = link_to 'View full answer', a %td - if a.provider == @profile.id #{link_to 'Delete my answer', a, :confirm => 'Are you sure?', :method => :delete} The problem is that when the user clicks on the destroy link, it redirects to the /answers/index. I want it to redirect to /questions/Q. What's the best way to do this? I know that there's a redirect_to method, but I don't know how to implement it when I want to redirect to an action for a different controller. It also needs to remember the question from which the answer is being deleted. I tried passing something like :question_id in link_to as: #{link_to 'Delete my answer', a, :confirm => 'Are you sure?', :question_id => @question.id, :method => :delete} In AnswersController#destroy: def destroy @answer = Answer.find(params[:id]) @answer.destroy respond_to do |format| format.html { redirect_to(answers_url) } format.xml { head :ok } end @question = Question.find(params[:question_id]) redirect_to question_path(@question) end The :question_id information is not passed to the destroy method, so I get this error: Couldn't find Question without an ID To confirm, I added a puts call before Question.find, and it returned nil.

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  • Designing a class in such a way that it doesn't become a "God object"

    - by devoured elysium
    I'm designing an application that will allow me to draw some functions on a graphic. Each function will be drawn from a set of points that I will pass to this graphic class. There are different kinds of points, all inheriting from a MyPoint class. For some kind of points it will be just printing them on the screen as they are, others can be ignored, others added, so there is some kind of logic associated to them that can get complex. How to actually draw the graphic is not the main issue here. What bothers me is how to make the code logic such that this GraphicMaker class doesn't become the so called God-Object. It would be easy to make something like this: class GraphicMaker { ArrayList<Point> points = new ArrayList<Point>(); public void AddPoint(Point point) { points.add(point); } public void DoDrawing() { foreach (Point point in points) { if (point is PointA) { //some logic here else if (point is PointXYZ) { //...etc } } } } How would you do something like this? I have a feeling the correct way would be to put the drawing logic on each Point object (so each child class from Point would know how to draw itself) but two problems arise: There will be kinds of points that need to know all the other points that exist in the GraphicObject class to know how to draw themselves. I can make a lot of the methods/properties from the Graphic class public, so that all the points have a reference to the Graphic class and can make all their logic as they want, but isn't that a big price to pay for not wanting to have a God class?

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