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  • Django DecimalField returns "None" instead of empty value

    - by Ed
    Is there a way to force django to display nothing instead of "None" for a Decimal Field that's been left blank? In my template, I show a list of all the values for a particular field. Each value is hyperlinked to a page that displays the results of a query filtered on that value. But because there are some entries with null value, my list includes actual DecimalField entries and "None" for all those that are empty. When a user clicks on None, django throws a validation error because you cannot query a DecimalField using a string. I could write if statements checking all instances of decimal fields for Nones and skipping them, but that is far from an elegant solution. Any advice? This is one part of the code, though there are other templates that derive the None value in slightly different manners: {% for item in choices %} <a href={% url app_views.field_choice item %}>{{ item }}</a><br> {% endfor %}

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  • Are these two functions overkill for sanitization?

    - by jpjp
    function sanitizeString($var) { $var = stripslashes($var); $var = htmlentities($var); $var = strip_tags($var); return $var; } function sanitizeMySQL($var) { $var = mysql_real_escape_string($var); $var = sanitizeString($var); return $var; } I got these two functions from a book and the author says that by using these two, I can be extra safe against XSS(the first function) and sql injections(2nd func). Are all those necessary? Also for sanitizing, I use prepared statements to prevent sql injections. I would use it like this: $variable = sanitizeString($_POST['user_input']); $variable = sanitizeMySQL($_POST['user_input']);

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  • What are some good design patterns for CRUD?

    - by Extrakun
    I am working with a number of data entities which can be created, read, updated and deleted, and I find myself writing more or less the same code for them. For example, I need to sometimes output data as JSON, and sometimes in a table format. I am finding myself writing 2 different types of view to export the data to. Also, the creation of those entities within DB usually differs just by the SQL statements and the input parameters. I am thinking of creating a strategy pattern to represent different 'contexts'. For example, the read() method of an AJAX context will be to return the data as JSON. However, I wonder if others have deal with this problem beforehand and will like to know what design patterns are usually use for CRUD operations.

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  • nested if: too many arguments?

    - by FLX
    For some reason this code creates problems: source="/foo/bar/" destination="/home/oni/" if [ -d $source ]; then echo "Source directory exists" if [ -d $destination ]; then echo "Destination directory exists" rsync -raz --delete --ignore-existing --ignore-times --size-only --stats --progress $source $destination chmod -R 0755 $destination else echo "Destination directory does not exists" fi else echo "Source directory does not exists" fi It errors out with: Source directory exists /usr/bin/copyfoo: line 7: [: too many arguments Destination directory does not exists I used nested if statements in bash before without a problem, what simple mistake am I overlooking? Thanks!

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  • WHERE clause confusion with PDO

    - by Greg
    I'm having some trouble understanding how to use prepared statements, when you need to match one value against several columns at once. In other words what instead of doing this: $stmt = $dbh-prepare("SELECT * FROM REGISTRY where name = ?"); $stmt-bindParam(':name', $name); I wanted to do this: $stmt = $dbh-prepare("SELECT * FROM REGISTRY where firstname = ? or lastname = ?"); with both '?' representing the same string.

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  • Are there any pitfalls to var something = something || {}

    - by puk
    I came across this answer where the poster suggested that the shorthand for if(typeof MyNamespace === 'undefined'){ var MyNamespace = {}; } is var MyNamespace = MyNamespace || {}; Would veteran programmers recommend the latter to simplify the code, or does it overly complicate things, like abusing ++ or -- in complex compound statements? EDIT The reason I asked is b/c a while back someone inspired me by pointing out that a lot of the people who think they are expert programmers make a lot of beginners mistakes. The case at the time was if (isReady){ //Do Something } And what he was saying is that a condition should mean something, isReady doesn't 'mean' anything, instead, we should use if (isReady === true){ //Do Something }

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  • Ant ignores attempt to override the LANG environment variable

    - by Steen
    We need to test a java build with the languages set to different values. I can manually (i.e. via export LANG=en_DK.UTF-8 and export LANG=en_DK) test that the unit tests run with the ant build script behaves differently, but I need to set the environment variable from ant. I have tried setting it using these methods (with the shell $LANG set to en_DK.UTF-8): using -D on the command line: ant -DLANG=en_DK using a build.properties file with the line LANG=en_DK in it using the following statements in the build.xml file (sorry for the formatting, I can't get SO to display it otherwise): : <property environment="ANTENV"/> <property name="ANTENV.LANG" value="en_DK"/> Using any of the three possibilities, and when run with -debug, ant reports that: Override ignored for property "LANG" What can I do to set the LANG environment variable from within ant?

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  • Program contains 2 nested loops which contain 4 if conditionals. How many paths?

    - by Student4Life
    In Roger Pressman's book, there is an example described of a program with 2 nested loops, the inner loop enclosing four if statements. The two loops can execute up to 20 times. He states that this makes about 10^14 paths. To get a number this large, it seems the paths inside the loops are multipllied by 2^40, i.e. 2^20 times 2^20 to account for all the possibilities of going through the two loops. I can't see why this factor is not just 400, i.e. 20 times 20. Can someone shed some light? It will help if you have the ppt slides and can see the program graph. Thanks.

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  • Query Concatenated Field (using SubSonic)

    - by jwynveen
    Is there a way to query against a concatenated field using MS SQL? For instance, what I want to do is something like: Select FirstName+' '+LastName as FullName from Attendees where FullName like '%Joe Schmoe%' The above doesn't work. What I have found works is: Select * from Attendee where FirstName+' '+LastName like '%Joe Schmoe%' but I can't figure out how to do that using a SubSonic SqlQuery. I have a number of joins and OR statements added dynamically that I don't want to have to write out the sql manually. Any help/ideas?

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  • Overview of PHP shorthand

    - by James Simpson
    I've been programming in PHP for years now, but I've never learned how to use any shorthand. I come across it from time to time in code and have a hard time reading it, so I'd like to learn the different shorthand that exists for the language sot hat I can read it and start saving time/lines by using it, but I can't seem to find a comprehensive overview of all of the shorthand. A Google search pretty much exclusively shows the shorthand for if/else statements, but I know there must be more than just that. By shorthand, I am talking about stuff like: ($var) ? true : false;

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  • -sizeWithFont Functions Differently on Device

    - by LucasTizma
    So I am seemingly encountering some strange behavior when using NSString's -sizeWithFont family of method calls depending on whether or not I'm invoking it on the iPhone Simulator or an actual device. Simply enough, when the receiver of the -sizeWithFont method call is nil, the resulting CGSize passed back on the Simulator is {0, 0}. However, on the device, it is the size of the bounding rectangle I specified in the method call. See the following log statements: Simulator: someString: (null) someStringSize: {0, 0} Device: someString: (null) someStringSize: {185, 3.40282e+38} The behavior on the Simulator is what I would expect. Not that this issue is difficult to circumvent, but 1) I'm a little confused why this family of functions would behave differently on the Simulator and an actual device, and 2) why does calling a method on a nil receiving return a particular result? Thanks for any pointers or insight you guys can provide! EDIT: I suppose I should mention that I'm building against the 3.1 SDK.

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  • Am I correct in my assumption about synchronized block?

    - by kunjaan
    I have a method shout() with a synchronized block. private void shout(){ System.out.println("SHOUT " + Thread.currentThread().getName()); synchronized(this){ System.out.println("Synchronized Shout" + Thread.currentThread().getName()); try { Thread.sleep(50); } catch (InterruptedException e) { e.printStackTrace(); } System.out.println("Synchronized Shout" + Thread.currentThread().getName()); } } If I have two Threads that run this method, am I correct in assuming that the two "Synchronized Shout" will always appear one after the other? There can be no other statements in between the "Synchronized Shout"?

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  • Windows Phone 7, MVVM, Silverlight and navigation best practice / patterns and strategies

    - by Matt F
    Whilst building a Windows Phone 7 app. using the MVVM pattern we've struggled to get to grips with a pattern or technique to centralise navigation logic that will fit with MVVM. To give an example, everytime the app. calls our web service we check that the logon token we've assigned the app. earlier hasn't expired. We always return some status to the phone from the web service and one of those might be Enum.AuthenticationExpired. If we receive that I'd imagine we'd alert the user and navigate back to the login screen. (this is one of many examples of status we might receive) Now, wanting to keep things DRY, that sort of logic feels like it should be in one place. Therein lies my question. How should I go about modelling navigation that relies on (essentially) switch or if statements to tell us where to navigate to next without repeating that in every view. Are there recognised patterns or techniques that someone could recommend? Thanks

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  • Does JavaME and/or Proguard reorder assignments?

    - by chrisdew
    This is a simplified example - I have two threads: Can JavaME and/Proguard ever reorder the obX = ... statements, such that thread_B will have a null pointer exception at ob2.someMethod? thread_A: Object ob1 = null; Object ob2 = null; ... ob1 = something1; ob2 = something2; thread_B: if (ob2 != null) { ob1.someMethod(); ... } P.S. I do realise that synchronising these will avoid the issue. Synchronisation has both a performance overhead, and more importantly, a chance to introduce deadlock.

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  • Returning several COUNT results from one ASP SQL statement

    - by user89691
    Say I have a table like this: Field1 Field2 Field3 Field4 fred tom fred harry tom tom dick harry harry and I want to determine what proportion of it has been completed for each field. I can execute: SELECT COUNT (Field1) WHERE (Field1 <> '') AS Field1Count SELECT COUNT (Field2) WHERE (Field2 <> '') AS Field2Count SELECT COUNT (Field3) WHERE (Field3 <> '') AS Field3Count SELECT COUNT (Field4) WHERE (Field4 <> '') AS Field4Count Is it possible to roll up these separate SQL statements into one that will return the 4 results in one hit? Is there any performance advantage to doing so (given that the number of columns and rows may be quite large in practice)?

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  • plist vs static array

    - by morticae
    Generally, I use static arrays and dictionaries for containing lookup tables in my classes. However, with the number of classes creeping quickly into the hundreds, I'm hesitant to continue using this pattern. Even if these static collections are initialized lazily, I've essentially got a bounded memory leak going on as someone uses my app. Most of these are arrays of strings so I can convert strings into NSInteger constants that can be used with switch statements, etc. I could just recreate the array/dictionary on every call, but many of these functions are used heavily and/or in tight loops. So I'm trying to come up with a pattern that is both performant and not persistent. If I store the information in a plist, does the iphoneOS do anything intelligent about caching those when loaded? Do you have another method that might be related?

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  • How can I work around the fact that in C++, sin(3.14159265) is not 0?

    - by Adam Doyle
    In C++, const double Pi = 3.14159265; cout << sin(Pi); // displays: 3.58979e-009 it SHOULD display the number zero I understand this is because Pi is being approximated, but is there any way I can have a value of Pi hardcoded into my program that will return 0 for sin(Pi)? (a different constant maybe?) In case you're wondering what I'm trying to do: I'm converting polar to rectangular, and while there are some printf() tricks I can do to print it as "0.00", it still doesn't consistently return decent values (in some cases I get "-0.00") The lines that require sin and cosine are: x = r*sin(theta); y = r*cos(theta); BTW: My Rectangular - Polar is working fine... it's just the Polar - Rectangular Thanks! edit: I'm looking for a workaround so that I can print sin(some multiple of Pi) as a nice round number to the console (ideally without a thousand if-statements)

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  • .NET library for generating javascript?

    - by Rune
    Do you know of a .NET library for generating javascript code? I want to generate javascript code based on information in my .NET application. I would like to be able to create an AST-like datastructure (using C#) and have it turned into valid javascript. I need to be able to create functions, statements, expressions etc., so I need something more than a JSON serializer - but I guess you could think of this as a (very) generalized JSON serializer. Do such libraries exist and if so, could you recommend any? Thank you.

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  • XSD data set with Oracle database

    - by Ed Woodcock
    Hi folks, I'm having a major issue with an XSD dataset mapping thingy that I'm using within my current project. We are using XSDs for some data abstraction (it's quicker and debatably more maintainable that using Parameterised SQL or a StoredProc), and on my machine (running in the VS development environment) thy're working fine. However, on the Pre-production server we use for our testing, the XSDs are not working correctly: some method calls will fail with the following error: System.ArgumentException: Value does not fall within the expected range. at Oracle.DataAccess.Client.OracleParameter.set_DbType(DbType value) Has anyone ever encountered this issue before? The methods being called are simple select statements using 1-3 parameters, and as I said before they work fine on my machine.

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  • MySQL Create tables without commiting current transaction

    - by user276648
    I'd like my program to be able to install plugins, and rollback all the changes made if an error occurs. So I create a transaction that keeps all the things that were added while installing the plugin. The problem is that the plugin may want to create tables, and doing so automatically commits the current transaction in MySQL. See Statements That Cause an Implicit Commit on MySQL web site. Any idea on how I could do it? I thought of using temporary tables as they are not automatically commited, unless they are using too much memory, but it looks like temporary tables cannot be rolled back anyway (and I haven't found a way to convert them to permanent tables). I just found out about "save points" (http://dev.mysql.com/doc/refman/5.1/en/savepoint.html), but I don't really understand how/when it should be used nor if it can help me achieve what I want.

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  • property not updating in object when page is posted

    - by Jared
    Hi I have set a property in a constructor like so function __construct() { $this->count = count(@$_SESSION['filearray']); //count how many files in array } and using it in condition statements if($this->count > 10) //then do something but it appears the count isn't being updated when I use another method of injecting values into this 'filearray' until I refresh the page. am I doing something wrong? I thought that my constructor would detect a change had been made in the session and whenever I call $this-count I would get the current count value but it seems to be 1 step behind until I refresh the page. If this is all vague I can include my form page that has all the method calls, but this is the jist of my question, why is my property not updating and how do I fix it :) TIA

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  • SQL Injection on INSERT

    - by freddy
    Hi, I'm currently testing Vulnerabiltys to SQL Injections for my companys application as an it-trainee. So I found, that the application is indeed vulnerable to injections because I can alter some of the insert statements. So I altered the insert Statement to this: INSERT INTO tablename( column, column1, column2, column3, column4,column5, column6, column7, column8 ) VALUES ( 10965972, 185796154, 25, 23,2023, '', CURRENT_DATE, 'v0201100', 18); DELETE * FROM tablename;-- , 2023,'a', CURRENT_DATE, 'v0201100', 18 ) I thought this should be a correct statement, but the MySQL Server returned this Error: MySQL Error: 1064 (You have an error in your SQL syntax;[...] Would be nice if somebody could help and tell my why the syntax is wrong... Thanks for your help :-)

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  • Is it possible to call a procedure within an SQL statement?

    - by darren
    Hi everyone I thought I would use a stored routine to clean up some of my more complex SQL statements. From what I've read, it seems impossible to use a stored procedure within an sql statement, and a stored function only returns a single value when what I need is a result set. I am using mySQL v5.0 SELECT p.`id`, gi.`id` FROM `sport`.`players` AS p JOIN `sport`.`gameinstances` AS gi ON p.`id` = gi.`playerid` WHERE (p.`playerid` IN (CALL findPlayers`("Canada", "2002"))) AND (gi.`instanceid` NOT IN (CALL findGameInstances`("Canada", "2002"))); For example, the procedures 'findPlayers' and 'findGameInstances' are are stored routines that execute some SQL and return a result set. I would prefer not to include their code directly within the statement above.

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  • Why is x86 ugly? aka Why is x86 considered inferior when compared to others?

    - by claws
    Hello, recently I've been reading some SO archives and encountered statements against x86 architecture. http://stackoverflow.com/questions/2667256/why-do-we-need-different-cpu-architecture-for-server-mini-mainframe-mixed-cor says "PC architecture is a mess, any OS developer would tell you that." http://stackoverflow.com/questions/82432/is-learning-assembly-language-worth-the-effort says "Realize that the x86 architecture is horrible at best" http://forums.anandtech.com/showthread.php?t=976577 says "Most colleges teach assembly on something like MIPS because it's much simpler to understand, x86 assembly is really ugly" and many more comments like Compared to most architectures, X86 sucks pretty badly. It's definitely the conventional wisdom that X86 is inferior to MIPS, SPARC, and PowerPC x86 is ugly I tried searching but didn't find any reasons. I don't find x86 bad probably because this is the only architecture I'm familiar with. Can someone kindly give me reasons for considering x86 ugly/bad/inferior compared to others.

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  • NHibernate: insert multiple items at once

    - by Gart
    Hello, all! I am learning NHibernate now and I would like to know is it possible to save multiple objects to database in one operation. For example, consider this test code private static void SaveTestBillNamesInSession(ISession session, params string[] names) { var bills = from name in names select new Bill { Name = name, DateRegistered = DateTime.Now, }; foreach (var bill in bills) session.SaveOrUpdate(bill); } This loop here generates many INSERT statements which may be sub-optimal in SQL Server 2008 which allows to include multiple data rows in one INSERT statement. Is it possible to rewrite this code to make use of this functionality - insert all the data in one operation?

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