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• mysql NO_AUTO_VALUE_ON_ZERO problem

  - by every_answer_gets_a_point

  at least i think that is what the problem is. i am updating a mysql database through excel using an odbc like this: With rs .AddNew ' create a new record ' add values to each field in the record .Fields("datapath") = dpath .Fields("analysistime") = atime .Fields("reporttime") = rtime .Fields("lastcalib") = lcalib .Fields("analystname") = aname .Fields("reportname") = rname .Fields("batchstate") = "bstate" .Fields("instrument") = "NA" .Update ' stores the new record End With besides the fields above, i also have a primary key auto_increment field called rowid for some reason the only field that gets updated is instrument. none of the other fields get updated.. however, when i try to do the same updating on a table that has no ROWID auto_increment field, it works perfectly has anyone else experienced this kind of issue before?

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• Java generic Interface performance

  - by halfwarp

  Simple question, but tricky answer I guess. Does using Generic Interfaces hurts performance? Example: public interface Stuff<T> { void hello(T var); } vs public interface Stuff { void hello(Integer var); <---- Integer used just as an example } My first thought is that it doesn't. Generics are just part of the language and the compiler will optimize it as though there were no generics (at least in this particular case of generic interfaces). Is this correct?

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• How to organize Windows Phone code base to target both 7.x and 8 platforms

  - by ljubomir

  I took over a Windows Phone project which was previously targeting WP 7.1 platform, and with the recent announcement of the new platform it should target WP 8 as well. My VS 2010 solution consists on several projects (Data access, Model, Tests and WP7 client app) and i am wandering on how to include support for WP8. I have to note that the code-base is not compatible with WP8, due to usage of Toolkit controls and other 3rd party libraries targeted for WP7.1 specifically. Also there is another problem with the Visual Studio versions - WP7.1 can work with VS 2010, but WP8 requires VS 2012. Should i move the whole code-base to VS 2012? Any good advice on how to organize code-base in a most meaningful way in order to avoid duplication and possible painful maintenance? I am thinking between one solution - multiple projects vs. multiple solutions - reusable projects approach. Code duplication (like two separate folders/solutions) should be the least possible approach (fallback).

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• Show/Hide GridView Header in ListView

  - by Chris

  I have a ListView in WPF, and I want to hide the headers for the ListView when the List the ItemsSource is bound to is null, and display the headers when the ItemsSource is not null and has at least 1 item in the collection. I have found the code online to hide the ListView headers like this: <Window.Resources> <Style x:Key="HideListViewHeaders" TargetType="{x:Type GridViewColumnHeader}"> <Setter Property="Visibility" Value="Collapsed" /> </Style> </Window.Resources> Thanks for any help!

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• HABTM checking for match of latest 3

  - by user333614

  Here's an interesting one for you folks... I have a HABTM (has_and_belongs_to_many) relationship between "Dogs" and "Trips". My goal is to find two result sets: 1) Dogs that have been on at least 1 of the last 3 trips and call that @dogs_current 2) Dogs that have NOT been on any of the last 3 trips and call that @dogs_old I found that I can find what the last 3 trips are by doing this in the Trip model: named_scope :last3, :order => 'date DESC', :limit => 3 But not sure how to use that list get 1 and 2. This hack works, but it seems ugly. There must be a better way! :) @dogs_current = [] @dogs_old = [] @dogs.each do |dog| if (Trip.last3 - dog.trips).size < 3 then @dogs_current << dog else @dogs_old << dog end end Any ideas? Thanks! -Cam

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• Is there any way that I can draw fast a chart with too many series? [on hold]

  - by Maryam Bagheri

  I have a project that need to draw a fast chart with many series. I must change start position of drawing to a favor position when user want. .Net Chart is slow in lots of series. I wanted to use this library: http://www.codeproject.com/Articles/32836/A-simple-C-library-for-graph-plotting?msg=4109664#xx4109664xx but loading speed is too slow when count of series increases. When I plot the chart, I must invalidate the chart for updates, drawing speed will be too slow if there are too many series. I need at least 900 series in a chart for this project. I wanted to use multiple layer series to decrease invalidate rate with the idea: http://www.codeproject.com/Articles/84833/Drawing-multiple-layers-without-flicker I do not know this idea would be helpful. I tested LightningChart control but it could not help me.

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• Chaining Animations (iPhone / MonoTouch)

  - by ifwdev

  I'm trying to slide some (custom) tab-like buttons into view. I don't want them all to move at the same time. Also, they shouldn't move one at at time (where one slides after the other finishes). I want each button to begin sliding slightly after the previous. Preferably it would happen on a curve but just a fixed .1 second offset would be alright too. Monotouch or Obj-C code is fine. I'm thinking there is something in the APIs for animating groups of items like this. Hopefully, at least...

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• How can I test if an input field contains foreign characters?

  - by zeckdude

  I have an input field in a form. Upon pushing submit, I want to validate to make sure the user entered non-latin characters only, so any foreign language characters, like Chinese among many others. Or at the very least test to make sure it does not contain any latin characters. Could I use a regular expression for this? What would be the best approach for this? I am validating in both javaScript and in PHP. What solutions can I use to check for foreign characters in the input field in both programming languages?

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• What do I need to know before working on an IM application?

  - by John

  I'm looking into building an IM-type application using Java stack (for the server at least). I'd be interested to see any information/advice on how applications like Skype/AIM/MSN work, as well as know any technologies/APIs that might be relevant. Without giving away the idea itself, it's perhaps more akin to Google Wave than Skype, but information useful for either is very welcome. Specific points I have already thought of include: Server Vs P2P... for reasons of logging my system will require all communication to go through a central server. Is this how other IM tools work... especially when audio/video comes into the equation? Cross-communication with other systems. Are there APIs for this or do all IM providers work hard to keep their protocol secret? The nature of what I'm designing means integration could probably only be limited, but it definitely seems worthwhile from a business perspective

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• PHP: How to begin testing large, existing codebase, and test for regression on production site?

  - by anonymous coward

  I'm in charge of at least one large body of existing PHP code, that desperately needs tests, and as well I need some method of checking the production site for errors. I've been working with PHP for many years, but am unfortunately new to testing. (Sorry!). While writing tests for code that has predictable outcomes seems easy enough, I'm having trouble wrapping my head around just how I can test the live site, to ensure proper output. I know that in a test environment, I could set up the database in a known state... but are there proper methods or techniques for testing a live site? Where should I begin? [I am aware of PHPUnit and SimpleTest, but haven't chosen one over the other yet]

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• C++ STL: Array vs Vector: Raw element accessing performance

  - by oh boy

  I'm building an interpreter and as I'm aiming for raw speed this time, every clock cycle matters for me in this (raw) case. Do you have any experience or information what of the both is faster: Vector or Array? All what matters is the speed I can access an element (opcode receiving), I don't care about inserting, allocation, sorting, etc. I'm going to lean myself out of the window now and say: Arrays are at least a bit faster than vectors in terms of accessing an element i. It seems really logical for me. With vectors you have all those security and controlling overhead which doesn't exist for arrays. (Why) Am I wrong? No, I can't ignore the performance difference - even if it is so small - I have already optimized and minimized every other part of the VM which executes the opcodes :)

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• Embedded quicktime video pause on click how to prevent?

  - by Marek

  I embedded a quicktime video in firefox. It works, but i would like to prevent the users to stop the video by clicking on it with the left mouse button. Reading the apple documentation i didn't find any answear. I came up with a workaround, i just put an almost invisible div over the whole video. The workaround works in firefox for os X, but oddly does not for the same version of firefox in windows. I would appreciate a way, workaround or not, to achive this at least in the windows/firefox environment. Thanks!

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• fastest method for minimum of two numbers

  - by user85030

  I was going through mit's opencourseware related to performance engineering. The quickest method (requiring least number of clock cycles) for finding the minimum of two numbers(say x and y) is stated as: min= y^((x^y) & -(x<y)) The output of the expression x < y can be 0 or 1 (assuming C is being used) which then changes to -0 or -1. I understand that xor can be used to swap two numbers. Questions: 1. How is -0 different from 0 and -1 in terms of binary? 2. How is that result used with the and operator to get the minimum? Thanks in advance.

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• How long people take to learn a new programming language?

  - by Cawas

  In general aspects, this might be a good reference for everyone. Having an idea of how long people take in average for properly learning how to code can give a very good idea on how dense or long is the path. Someone who never programmed should take weeks or months, even years maybe while someone who's already experienced in the area and know at least 2 different languages might take days, hours or even minutes to start coding. But other than being able to write code that runs, there are ways to write the same program, and it's much harder to get deep knowledge on that than actually being able to program. And sometimes languages differ a lot from one to another on that aspect as well. For instance, we should never have to worry with code-injection in JavaScript like we do in C. So, is there any place we can see some good numbers for how long it takes to learn a language, maybe divided into level of knowledge categories, languages and paradigms, etc?

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• Correct way to textually report the remaining time on a long running process?

  - by Ryan

  So you have a long running process, perhaps with a progress bar, and you want a text estimate of the remaining time, eg: "5 minutes remaining" "30 seconds remaining" etc. If you don't actually want to report clock time (due to accuracy or resolution or update-rate issues) but want to stick to the text summary, what is the correct paradigm? Is "one minute" left displayed from 0 to 60 seconds? or from 1:00 to 1:59? Say there's 1:35 Left - is that "2 minutes remaining" or "1 minute remaining"? Do you just pare it down to "A few minutes left" when you're less than 3 minutes? What is the preferred (least user-frustrating) method?

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• How can I find days between different paired rows?

  - by Anthony

  I've been racking my brain about how to do this in one query without PHP code. In a nutshell, I have a table that records email activity. For the sake of this example, here is the data: recipient_id activity date 1 delivered 2011-08-30 1 open 2011-08-31 2 delivered 2011-08-30 3 delivered 2011-08-24 3 open 2011-08-30 3 open 2011-08-31 The goal: I want to display to users a single number that tells how many recipients open their email within 24 hours. E.G. "Users that open their email within 24 hours: 13 Readers" In the case of the sample data, above, the value would be "1". (Recipient one was delivered an email and opened it the next day. Recipient 2 never opened it and recipient 3 waited 5 days.) Can anyone think of a way to express the goal in a single query? Reminder: In order to count, the person must have a 'delivered' tag and at least one 'open' tag. Each 'open' tag only counts once per recipient.

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• Is pthread_spin_trylock safe inside of sigsegv handler of multithreaded application?

  - by TWMouton

  I am trying to implement a handler that on SIGSEGV will collect some information such as process-id, thread-id and a backtrace and write this information to a file/pipe/socket. The problem lies in that there is the (probably pretty high) possibility that if one thread experienced a SIGSEGV that the others will shortly follow. If two threads happen to make it to the bit of code where they're writing their report out at the same time then they'll interleave their writing (to the same file). I know that I should only be using async-signal-safe functions as detailed in signal(7) I also have seen at least two cases here and video linked in top answer here where others have used pthread_spin_trylock to get around this problem. Is this a safe way to prevent the above problem?

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• MySQL Integer vs DateTime index

  - by David Kuridža

  Let me start by saying I have looked at many similar questions asked, but all of them relate to Timestamp and DateTime field type without indexing. At least that is my understanding. As we all know, there are certain advantages when it comes to DateTime. Putting them aside for a minute, and assuming table's engine is InnoDB with 10+ million records, which query would perform faster when criteria is based on: DateTime with index int with index In other words, it is better to store date and time as DateTime or UNIX timestamp in int? Keep in mind there is no need for any built-in MySQL functions to be used.

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• How to get the Primary/Secondary color in jQuery UI Theme

  - by simonsanderson

  Is there a way to reference the colours used in the jQuery themes without creating a simple style for each theme that I may choose to use? Example: I have some text as follows <div>Hello</div> which I'd like to be change colour in line with my theme of the day. I wish to use the primary colour from a theme (say ui-lightness) which is "#1c94c4" as defined in several of the styles such as ui-state-default in ui-lightness.css The problem is that if I do the following <div class='ui-state-default'>Hello</div> I get all the other style effects, like borders and background colour, which are not right for my application What I'd like to do is something like <div class='ui-primary-color'>Hello</div> which would automatically change only the colour dependent on the theme. PS. Doing a pre-build pre-processing step to parse the themes and generate a customised css style would be my least favourable option here!

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• StructureMap DI on Model Assembly

  - by Dan dot net

  I’m new to Dependency Injection and had a question/need guidance. I had an application that used the repository pattern for data access. I used StructureMap to get the correct repository and all worked well. I have since broken out my model (including the repository logic) into its own assembly and added a service layer. In the interest of DI the service layer class takes an IRepository in its constructor. This seems wrong to me as now all consumers of my model need to know about the repository (at least configure their DI to know which one to use). I feel like that is getting into the guts of the model. What sounds wrong with this?

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• What's the most performance effective way to have a webbrowser inside a class library ?

  - by Xaqron

  I'm developing a class library. Need some data from internet and this cannot be done with HttpWebRequest in my case so I wanna use WebBrowser component. WebBrowser is used for opening a single page and fetch some data from it, so WebBrowser life-time is very short. Running thread is MTA and no message pump or STA thread is available by default (class library is used by an ASP.NET application). How to create a WebBrowser object, run it with a STA thread, fetch data from a web page and finally dispose it with the least performance impact on the application ? I just need the idea/concept and will find details myself. Thanks guys

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• What is the most underused or underappreciated design pattern?

  - by Rob Packwood

  I have been reading a lot on design patterns lately and some of them can make our lives much easier and some of them seem to just complicate things (at least to me they do). I am curious to know what design patterns everyone sees as underunsed or underappreciated. Some patterns are simple and many people do not even realize they are using a pattern (decorator probably being the most used, without realized). My goal from this is to give us pattern-newbies some appreciation for some of the more complex or unknown patterns and why we should use them.

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• MySQL features I can rely on being available

  - by xrstf

  So I'm developing a PHP/MySQL based CMS which requires PHP 5.1 and MySQL 5.0 (with InnoDB support) at least. I'm now wondering what features of MySQL I can safely use without noticing one day that "Oh, well, that crappy hoster has disabled feature X, damn, now I'm screwed." So my question is, which of these features can become problematic (= can be disabled, require special configuration, require user privilege): transactions and FKs in InnoDB (of course unavailable to MyISAM) table locking (MyISAM and InnoDB) stored procedures I just want to know once and for all what's the minimal feature set I can expect from MySQL.

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• MYSQL: COUNT with GROUP BY, LEFT JOIN and WHERE clause doesn't return zero values

  - by Paul Norman

  Hi guys, thanks in advance for any help on this topic! I'm sure this has a very simply answer, but I can't seem to find it (not sure what to search on!). A standard count / group by query may look like this: SELECT COUNT(`t2`.`name`) FROM `table_1` `t1` LEFT JOIN `table_2` `t2` ON `t1`.`key_id` = `t2`.`key_id` GROUP BY `t1`.`any_col` and this works as expected, returning 0 if no rows are found. So does: SELECT COUNT(`t2`.`name`) FROM `table_1` `t1` LEFT JOIN `table_2` `t2` ON `t1`.`key_id` = `t2`.`key_id` WHERE `t1`.`another_column` = 123 However: SELECT COUNT(`t2`.`name`) FROM `table_1` `t1` LEFT JOIN `table_2` `t2` ON `t1`.`key_id` = `t2`.`key_id` WHERE `t1`.`another_column` = 123 GROUP BY `t1`.`any_col` only works if there is at least one row in table_1 and fails miserably returning an empty result set if there are zero rows. I would really like this to return 0! Anyone enlighten me on this? Beer can be provided in exchange if you are in London ;-)

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• Ignore document style rules in one element.

  - by panzi

  I write a greasemonkey script that adds sticky notes to websites. Because there sometimes are pretty strange style rules used in some websites the sticky notes sometimes turn up messed up (or at least not looking like I want them to look). Is there a way to say "under this element do not apply any generic stylerules"? So that rules associated with tag names are not applied, but rules associated with certain classes and ids still are. Or does anyone have a better idea on how to ensure that only my styles are applied to the sticky notes?

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