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  • Design of std::ifstream class

    - by Nawaz
    Those of us who have seen the beauty of STL try to use it as much as possible, and also encourage others to use it wherever we see them using raw pointers and arrays. Scott Meyers have written a whole book on STL, with title Effective STL. Yet what happened to the developers of ifstream that they preferred char* over std::string. I wonder why the first parameter of ifstream::open() is of type const char*, instead of const std::string &. Please have a look at it's signature: void open(const char * filename, ios_base::openmode mode = ios_base::in ); Why this? Why not this: void open(const string & filename, ios_base::openmode mode = ios_base::in ); Is this a serious mistake with the design? Or this design is deliberate? What could be the reason? I don't see any reason why they have preferred char* over std::string. Note we could still pass char* to the latter function that takes std::string. That's not a problem! By the way, I'm aware that ifstream is a typedef, so no comment on my title.:P. It looks short that is why I used it. The actual class template is : template<class _Elem,class _Traits> class basic_ifstream;

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  • MySQL default value based on view

    - by Jake
    Basically I have a bunch of views based on a simple discriminator column (eg. CREATE VIEW tablename AS SELECT * FROM tablename WHERE discrcolumn = "discriminator value"). Upon inserting a new row into this view, it should insert "discriminator value" into discrcolumn. I tried this, but apparently MySQL doesn't figure this out itself, as it throws an error "Field of view viewname underlying table does not have a default value". The discriminator column is set to NOT NULL of course. How do I mend this? Perhaps a pre-insert trigger? UPDATE: Triggers won't work on views, see below comment. Would it work to create a trigger on the table which uses a variable, and set that variable at establishing the connection? For each connection the value of that variable would be the same, but it could differ from other connections. EDIT: This appears to work... Setup: CREATE TRIGGER insert_[tablename] BEFORE INSERT ON [tablename] FOR EACH ROW SET NEW.[discrcolumn] = @variable Runtime: SET @variable = [descrvalue]; INSERT INTO [viewname] ([columnlist]) VALUES ([values]);

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  • How to get MySQL database to appear on index.php

    - by Teddy Truong
    Hi, I have a submission form on my website (index.php) and I have the data(user submissions) being stored into a MySQL database. Right now, I have the user submitting a post and then the page directs them to an update.php which shows what they inputed. However, I want all of the data in the database in MySQL to be shown on the index.php. It's a lot like a comment system. User submits a post... and sees their post above the other submitted posts all on the same page. I think I'm missing AJAX... ? Here is the code for index.php <div align="center"> <p>&nbsp;</p> <h2 align="center" class="Title"><em><strong>REDACTED</strong></em></h2> <form id="form1" name="form1" method="post" action="update.php"> <hr /> <label><br /> <form action="update.php" method="post"> REDACTED: <input type="text" name="text" /> <input type="submit" /> </form> </label> </form> </div> On update.php I have this: ?php $text = $_POST['text']; $myString = "REDACTED"; mysql_connect ("db----.net", "-----3", "------------") or die ('Error: ' . mysql_error()); mysql_select_db ("-----------"); $query="INSERT INTO TextArea (ID, text) VALUES ('NULL', '".$text."')"; mysql_query($query) or die ('Error updating database'); echo " $myString "," $text "; ?> Thanks a lot!

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  • AM I using DO WHILE NOT and EOF in VBscript Properly

    - by Derek Drummond
    This block of code is causing my page to fail to load. When I comment out the line `DO WHILE NOT Rs.EOF the page loads properly. SQL_Command_String = "SELECT * FROM Seminars WHERE [SeminarID] = 5 ORDER BY DESC" Rs = SQLConnection.Execute(SQL_Command_String) DO WHILE NOT Rs.EOF file1 = "./seminars/" & seminar_type & "/" & seminar_year & "/" & Rs("Date") & "-" & Rs("Year") & "_" & Rs("Last") & ".pdf" file2 = "./seminars/" & seminar_type & "/" & seminar_year & "/" & Rs("Date") & "-" & seminar_year & "_" & Rs("Last") & "(handouts).pdf" file3 = "./seminars/" & seminar_type & "/" & seminar_year & "/" & Rs("Date") & "-" & seminar_year & "_" & Rs("Last") & "_Flyer.pdf" Rs.MoveNext loop Is the SQL_Command_String an invalid SQL Command or is my reader not being used properly when I try to build that specific file path e.g. Rs("Date")? Is there an option where I could do something like: DO WHILE RS.hasNextLine

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  • What is the preferred way in C++ for converting a builtin type (int) to bool?

    - by Martin
    When programming with Visual C++, I think every developer is used to see the warning warning C4800: 'BOOL' : forcing value to bool 'true' or 'false' from time to time. The reason obviously is that BOOL is defined as int and directly assigning any of the built-in numerical types to bool is considered a bad idea. So my question is now, given any built-in numerical type (int, short, ...) that is to be interpreted as a boolean value, what is the/your preferred way of actually storing that value into a variable of type bool? Note: While mixing BOOL and bool is probably a bad idea, I think the problem will inevitably pop up whether on Windows or somewhere else, so I think this question is neither Visual-C++ nor Windows specific. Given int nBoolean; I prefer this style: bool b = nBoolean?true:false; The following might be alternatives: bool b = !!nBoolean; bool b = (nBoolean != 0); Is there a generally preferred way? Rationale? I should add: Since I only work with Visual-C++ I cannot really say if this is a VC++ specific question or if the same problem pops up with other compilers. So it would be interesting to specifically hear from g++ or users how they handle the int-bool case. Regarding Standard C++: As David Thornley notes in a comment, the C++ Standard does not require this behavior. In fact it seems to explicitly allow this, so one might consider this a VC++ weirdness. To quote the N3029 draft (which is what I have around atm.): 4.12 Boolean conversions [conv.bool] A prvalue of arithmetic, unscoped enumeration, pointer, or pointer to member type can be converted to a prvalue of type bool. A zero value, null pointer value, or null member pointer value is converted to false; any other value is converted to true. (...)

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  • iPad keyboard will not dismiss if navigation controller presentation style is "form sheet".

    - by Kalle
    UPDATE: This is apparently "works as intended" classed by Apple. See accepted answer below for details. Update: this question is about a behavior discovered in the iPad keyboard, where it refuses to be dismissed if shown in a modal dialog with a navigation controller. Basically, if I present the navigation controller with the following line: navigationController.modalPresentationStyle = UIModalPresentationFormSheet; The keyboard refuses to be dismissed. If I comment out this line, the keyboard goes away fine. ... I've got two textFields, username and password; username has a Next button and password has a Done button. The keyboard won't go away if I present this in a modal navigation controller. WORKS broken *b = [[broken alloc] initWithNibName:@"broken" bundle:nil]; [self.view addSubview:b.view]; DOES NOT WORK broken *b = [[broken alloc] initWithNibName:@"broken" bundle:nil]; UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:b]; navigationController.modalPresentationStyle = UIModalPresentationFormSheet; navigationController.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal; [self presentModalViewController:navigationController animated:YES]; [navigationController release]; [b release]; If I remove the navigation controller part and present 'b' as a modal view controller by itself, it works. Is the navigation controller the problem? WORKS broken *b = [[broken alloc] initWithNibName:@"broken" bundle:nil]; b.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal; [self presentModalViewController:b animated:YES]; [b release]; WORKS broken *b = [[broken alloc] initWithNibName:@"broken" bundle:nil]; UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:b]; [self presentModalViewController:navigationController animated:YES]; [navigationController release]; [b release];

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  • Bash script to insert code from one file at a specific location in another file?

    - by Kurtosis
    I have a fileA with a snippet of code, and I need a script to insert that snippet into fileB on the line after a specific pattern. I'm trying to make the accepted answer in this thread work, but it's not, and is not giving an error so not sure why not: sed -e '/pattern/r text2insert' filewithpattern Any suggestions? pattern (insert snippet on line after): def boot { also tried escaped pattern but no luck: def\ boot\ { def\ boot\ \{ fileA snippet: LiftRules.htmlProperties.default.set((r: Req) => new Html5Properties(r.userAgent)) fileB (Boot.scala): package bootstrap.liftweb import net.liftweb._ import util._ import Helpers._ import common._ import http._ import sitemap._ import Loc._ /** * A class that's instantiated early and run. It allows the application * to modify lift's environment */ class Boot { def boot { // where to search snippet LiftRules.addToPackages("code") // Build SiteMap val entries = List( Menu.i("Home") / "index", // the simple way to declare a menu // more complex because this menu allows anything in the // /static path to be visible Menu(Loc("Static", Link(List("static"), true, "/static/index"), "Static Content"))) // set the sitemap. Note if you don't want access control for // each page, just comment this line out. LiftRules.setSiteMap(SiteMap(entries:_*)) // Use jQuery 1.4 LiftRules.jsArtifacts = net.liftweb.http.js.jquery.JQuery14Artifacts //Show the spinny image when an Ajax call starts LiftRules.ajaxStart = Full(() => LiftRules.jsArtifacts.show("ajax-loader").cmd) // Make the spinny image go away when it ends LiftRules.ajaxEnd = Full(() => LiftRules.jsArtifacts.hide("ajax-loader").cmd) // Force the request to be UTF-8 LiftRules.early.append(_.setCharacterEncoding("UTF-8")) } }

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  • Meaning of Execute_priv on mysql.db table

    - by Ben Reisner
    I created user 'restriceduser' on my mysql server that is 'locked down'. The mysql.user table has a N for all priveledges for that account. The mysql.db table has Y for only Select, Insert, Update, Delete, Create, Drop; all other privileges are N for that account. I tried to create a stored procedure and then grant him access to run only that procedure, no others, but it does not work. The user receives: Error: execute command denied to user 'restricteduser'@'%' for routine 'mydb.functionname' The stored procedure: CREATE DEFINER = 'restriceduser'@'%' FUNCTION `functionname`(sIn MEDIUMTEXT, sformat MEDIUMTEXT) RETURNS int(11) NOT DETERMINISTIC CONTAINS SQL SQL SECURITY DEFINER COMMENT '' BEGIN .... END; The grant statement I tried: GRANT EXECUTE ON PROCEDURE mydb.functionname TO 'restricteduser'@'%'; I was able to work around by modifying his mysql.db entry with update mysql.db set execute_priv='Y' where user='restricteduser' This seems to be more then I want, because it opens up permissions for him to run any stored procedure in that database, while I only wanted him to have permissions to run the designated function. Does anyone see where my issue may lie?

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  • Jsp static import

    - by folone
    I've created a Spring Roo project. Everything looks fine. Now I want to add a form with a text input and a button to my index.jspx. This form will change a static field currentUser in my ToDo class. So I'm adding: <form> <%@ page import="static com.mypack.domain.ToDo.*" %> <label for="_username_id">My name is:</label> <% currentUser = request.getParameter("username"); %> <input type="text" id="username" name="username" maxlength="30" path="username" size="0" value="<%= currentUser %>"/> <input type="submit"/> </form> somewhere in the middle of it. And now it won't work: This page contains the following errors: error on line 6 at column 20: StartTag: invalid element name Below is a rendering of the page up to the first error. function readCookie(name) { var nameEQ = name + '='; var ca = document.cookie.split(';'); for(var i=0;i If I comment the lines above, it works just fine. What is wrong? Is there a way to write a value to a static field of a class from a jsp page? How do I work around this?

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  • Using ZLib unit to compress files vs using ZipForge

    - by user193655
    There are many questions on zipping in Delphi, anyway this is not a duplicate. I am using ZipForge for zip/unzip capability in my application. Currently I use 2 features of ZipForge: 1) zip and unzip (!) 2) password protect the archives Now I am removing the password from all the archives so I need only to zip and unzip files. I zip them just for minimizing bandwith when uploading/downloading files from the server. So my idea is to process all files once for unzipping them (with password) and rezipping them without password. I have nothing against ZipForge, anyway it is an extra component, every time I upgrade to a newest Delphi version I have to wait for the new IDE support and moreover the more components the more problems during the installation. So since what I do is very simple I'd like to replace ZipForge with 2 simple functinos using the ZLib unit. I found (and tested) the functions here on Torry's. What do you think of using Zlib unit? Do you see any potential problem that I would not have with ZipForge? Can you comment on speed?

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  • What is the cleanest way to use anonymous functions?

    - by Fletcher Moore
    I've started to use Javascript a lot more, and as a result I am writing things complex enough that organization is becoming a concern. However, this question applies to any language that allows you to nest functions. Essentially, when should you use an anonymous function over a named global or inner function? At first I thought it was the coolest feature ever, but I think I am going overboard. Here's an example I wrote recently, ommiting all the variable delcarations and conditionals so that you can see the structure. function printStream() { return fold(function (elem, acc) { ... var comments = (function () { return fold(function (comment, out) { ... return out + ...; }, '', elem.comments); return acc + ... + comments; }, '', data.stream); } I realized though (I think) there's some kind of beauty in being so compact, it is probably isn't a good idea to do this in the same way you wouldn't want a ton of code in a double for loop.

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  • What are Code Smells? What is the best way to correct them?

    - by Rob Cooper
    OK, so I know what a code smell is, and the Wikipedia Article is pretty clear in its definition: In computer programming, code smell is any symptom in the source code of a computer program that indicates something may be wrong. It generally indicates that the code should be refactored or the overall design should be reexamined. The term appears to have been coined by Kent Beck on WardsWiki. Usage of the term increased after it was featured in Refactoring. Improving the Design of Existing Code. I know it also provides a list of common code smells. But I thought it would be great if we could get clear list of not only what code smells there are, but also how to correct them. Some Rules Now, this is going to be a little subjective in that there are differences to languages, programming style etc. So lets lay down some ground rules: ** ONE SMELL PER ANSWER PLEASE! & ADVISE ON HOW TO CORRECT! ** See this answer for a good display of what this thread should be! DO NOT downmod if a smell doesn't apply to your language or development methodology We are all different. DO NOT just quickly smash in as many as you can think of Think about the smells you want to list and get a good idea down on how to work around. DO downmod answers that just look rushed For example "dupe code - remove dupe code". Let's makes it useful (e.g. Duplicate Code - Refactor into separate methods or even classes, use these links for help on these common.. etc. etc.). DO upmod answers that you would add yourself If you wish to expand, then answer with your thoughts linking to the original answer (if it's detailed) or comment if its a minor point. DO format your answers! Help others to be able to read it, use code snippets, headings and markup to make key points stand out!

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  • Why does GCC need extra declarations in templates when VS does not?

    - by Kyle
    template<typename T> class Base { protected: Base() {} T& get() { return t; } T t; }; template<typename T> class Derived : public Base<T> { public: Base<T>::get; // Line A Base<T>::t; // Line B void foo() { t = 4; get(); } }; int main() { return 0; } If I comment out lines A and B, this code compiles fine under Visual Studio 2008. Yet when I compile under GCC 4.1 with lines A and B commented, I get these errors: In member function ‘void TemplateDerived::foo()’: error: ‘t’ was not declared in this scope error: there are no arguments to ‘get’ that depend on a template parameter, so a declaration of ‘get’ must be available Why would one compiler require lines A and B while the other doesn't? Is there a way to simplify this? In other words, if derived classes use 20 things from the base class, I have to put 20 lines of declarations for every class deriving from Base! Is there a way around this that doesn't require so many declarations?

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  • Multiple forms using Rails & jQuery & AJAX

    - by biggie8199
    I have multiple coupons on a page and I'm trying to get comments to work on each coupon. So for each coupon i have a comments form. Im using jQuery + Ajax to accomplish this. Here's what my code looks like. Coupon Page <p>Comments:</p> <% form_for(@comment) do |f| %> <%= f.label :body %><br /><%= f.text_field :body, :size => "24" %> <%= f.hidden_field :coupon_id, :value => coupon.id %> <%= f.submit "Save" %> <% end %> Application.js jQuery.ajaxSetup({ 'beforeSend': function(xhr) {xhr.setRequestHeader("Accept", "text/javascript")} }) jQuery.fn.submitWithAjax = function() { this.submit(function() { $.post(this.action, $(this).serialize(), null, "script"); return false; }) return this; }; $(document).ready(function() { $("#new_comment").submitWithAjax(); }) I tried changing the jQuery selector to a class $(".new_comment").submitWithAjax(); Thinking that would work, now all the submit buttons work, however it posts only the first form on the page. What can I change to make it so ajax submits the correct form and not the first one?

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  • Mapping enum with fluent nhibernate

    - by Puneet
    I am following the http://wiki.fluentnhibernate.org/Getting%5Fstarted tutorial to create my first NHibernate project with Fluent NHibernate I have 2 tables 1) Account with fields Id AccountHolderName AccountTypeId 2) AccountType with fields Id AccountTypeName Right now the account types can be Savings or Current So the table AccountTypes stores 2 rows 1 - Savings 2 - Current For AccoutType table I have defined enum public enum AccountType { Savings=1, Current=2 } For Account table I define the entity class public class Account { public virtual int Id {get; private set;} public virtual string AccountHolderName {get; set;} public virtual string AccountType {get; set;} } The fluent nhibernate mappings are: public AgencyMap() { Id(o => o.Id); Map(o => o.AccountHolderName); Map(o => o.AccountType); } When I try to run the solution, it gives an exception - InnerException = {"(XmlDocument)(2,4): XML validation error: The element 'class' in namespace 'urn:nhibernate-mapping-2.2' has incomplete content. List of possible elements expected: 'meta, subselect, cache, synchronize, comment, tuplizer, id, composite-id' in namespace 'ur... I guess that is because I have not speciofied any mapping for AccountType. The questions are: How can I use AccountType enum instead of a AccountType class? Maybe I am going on wrong track. Is there a better way to do this? Thanks!

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  • propositional theorems

    - by gcc
    wang's theorem to prove theorems in propositonal calculus Label Sequent Comment S1: P ? Q, Q ? R, ¬R ? ¬P Initial sequent. S2: ¬P ? Q, ¬Q ? R, ¬R ? ¬P Two applications of R5. S3: ¬P ? Q, ¬Q ? R ? ¬P, R Rl. S4: ¬P, ¬Q ? R ? ¬P, R S4 and S5 are obtained from S3 with R3. Note that S4 is an axiom since P appears on both sides of the sequent ar- row at the top level. S5: Q, ¬Q ? R ? ¬P, R The other sequent generated by the ap- plication of R3. S6: Q, ¬Q ? ¬P, R S6 and S7 are obtained from S5 using R3. S7: Q, R ? ¬P, R This is an axiom. S8: Q ? ¬P, R, Q Obtained from S6 using R1. S8 is an axiom. The original sequent is now proved, since it has successfully been transformed into a set of three axioms with no unproved sequents left over. //R1,R2,R3,R4,R5 is transformation myhomework is so complicate as you can see and i must finish homework in 4 days i just want help ,can you show me how i should construct the algorithm or how i should take and store the input

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  • problem with binarysearch algorithm

    - by arash
    hi friends,the code below belongs to binary search algorithm,user enter numbers in textbox1 and enter the number that he want to fing with binarysearch in textbox2.i have a problem with it,that is when i enter for example 15,21 in textbox1 and enter 15 in textbox2 and put brakpoint on the line i commented below,and i understood that it doesnt put the number in textbox2 in searchnums(commented),for more explanation i comment in code.thanks in advance public void button1_Click(object sender, EventArgs e) { int searchnums = Convert.ToInt32(textBox2.Text);//the problem is here,the value in textbox2 doesnt exist in searchnums and it has value 0. int result = binarysearch(searchnums); MessageBox.Show(result.ToString()); } public int binarysearch(int searchnum) { string[] source = textBox1.Text.Split(','); int[] nums = new int[source.Length]; for (int i = 0; i < source.Length; i++) { nums[i] = Convert.ToInt32(source[i]); } int first =0; int last = nums.Length; int mid = (int)Math.Floor(nums.Length / 2.0); while (1<= nums.Length) { if (searchnum < nums[mid]) { last = mid - 1; } if (searchnum > nums[mid]) { first = mid + 1; } else { return nums[mid]; } } return -1; }

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  • WPF BackGroundWorker ProgressChanged not updating textblock

    - by user354469
    I have the method below that seems to behaving strangely. The ProgressChanged and RunWorkerCompleted seem to be updating themselves at the same time. If I comment out the RunWorkerCompleted code which updates the Textblock I see the ProgressChanged taking effect after the data is transferred. What am i doing wrong here? I obviously want the textblock to show I'm getting data, then change when I have finished getting the data. public void GetAppointmentsBackground() { System.Windows.Threading.Dispatcher webServiceDispatcher = this.Dispatcher; worker = new BackgroundWorker(); worker.WorkerReportsProgress = true; worker.DoWork += delegate(object sender, DoWorkEventArgs args) { GetAppointmentsForDayDelegate getAppt = new GetAppointmentsForDayDelegate(GetAppointmentsForDay); webServiceDispatcher.BeginInvoke(getAppt); (sender as BackgroundWorker).ReportProgress(25); }; worker.ProgressChanged += delegate(object s, ProgressChangedEventArgs args) { txtMessages.Text = "Contacting Server"; }; worker.RunWorkerCompleted += delegate(object s, RunWorkerCompletedEventArgs args) { txtMessages.Text = "Completed Successfully"; }; worker.RunWorkerAsync(); }

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  • css layout - break down

    - by Luke
    So I am trying to get the effect of having two frames inside a 750px wide frame. .news {width: 750px;} .news1 {width:550px;} .news2 {width:200px;} Very simple css at this stage. The html/php: <div class="news"> <div class="format"><a href='newspiece.php?news=<?echo $id?>'><?echo "$subject\n";?></a></div> <div class="news1"> <? echo "<div class='content'>"; echo nl2br($comment); echo "<a href='newspiece.php?news=$id'>..[read more]..</a>\n"; echo "</div>"; ?> <h5><? echo "Posted by <a href=\"userprofile.php?user=$posted\">$posted</a> on $final_date\n";?></h5> <? echo "<br />\n";?> </div> <div class="news2"> <img src="images/news/<? echo $id?>.jpg" /> </div> </div>] THe problem I am getting is that the image that should be on the right is going underneath. So in effect, news1 is above news2, rather than side by side. Any ideas?

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  • Count problem in SQL when I want results from diffrent tabels

    - by Nicklas
    ALTER PROCEDURE GetProducts @CategoryID INT AS SELECT COUNT(tblReview.GroupID) AS ReviewCount, COUNT(tblComment.GroupID) AS CommentCount, Product.GroupID, MAX(Product.ProductID) AS ProductID, AVG(Product.Price) AS Price, MAX (Product.Year) AS Year, MAX (Product.Name) AS Name, AVG(tblReview.Grade) AS Grade FROM tblReview, tblComment, Product WHERE (Product.CategoryID = @CategoryID) GROUP BY Product.GroupID HAVING COUNT(distinct Product.GroupID) = 1 This is what the tabels look like: **Product** |**tblReview** | **tblComment** ProductID | ReviewID | CommentID Name | Description | Description Year | GroupID | GroupID Price | Grade | GroupID GroupID is name_year of a Product, ex Nike_2010. One product can have diffrent sizes for exampel: ProductID | Name | Year | Price | Size | GroupID 1 | Nike | 2010 | 50 | 8 | Nike_2010 2 | Nike | 2010 | 50 | 9 | Nike_2010 3 | Nike | 2010 | 50 | 10 | Nike_2010 4 | Adidas| 2009 | 45 | 8 | Adidas_2009 5 | Adidas| 2009 | 45 | 9 | Adidas_2009 6 | Adidas| 2009 | 45 | 10 | Adidas_2009 I dont get the right count in my tblReview and tblComment. If I add a review to Nike size 8 and I add one review to Nike size 10 I want 2 count results when I list the products with diffrent GroupID. Now I get the same count on Reviews and Comment and both are wrong. I use a datalist to show all the products with diffrent/unique GroupID, I want it to be like this: ______________ | | | Name: Nike | | Year: 2010 | | (All Sizes) | | x Reviews | | x Comments | | x AVG Grade | |______________| All Reviewcounts, Commentcounts and the Average of all products with the same GroupID, the Average works great.

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  • Can I get rid of this read lock?

    - by Pieter
    I have the following helper class (simplified): public static class Cache { private static readonly object _syncRoot = new object(); private static Dictionary<Type, string> _lookup = new Dictionary<Type, string>(); public static void Add(Type type, string value) { lock (_syncRoot) { _lookup.Add(type, value); } } public static string Lookup(Type type) { string result; lock (_syncRoot) { _lookup.TryGetValue(type, out result); } return result; } } Add will be called roughly 10/100 times in the application and Lookup will be called by many threads, many of thousands of times. What I would like is to get rid of the read lock. How do you normally get rid of the read lock in this situation? I have the following ideas: Require that _lookup is stable before the application starts operation. The could be build up from an Attribute. This is done automatically through the static constructor the attribute is assigned to. Requiring the above would require me to go through all types that could have the attribute and calling RuntimeHelpers.RunClassConstructor which is an expensive operation; Move to COW semantics. public static void Add(Type type, string value) { lock (_syncRoot) { var lookup = new Dictionary<Type, string>(_lookup); lookup.Add(type, value); _lookup = lookup; } } (With the lock (_syncRoot) removed in the Lookup method.) The problem with this is that this uses an unnecessary amount of memory (which might not be a problem) and I would probably make _lookup volatile, but I'm not sure how this should be applied. (John Skeets' comment here gives me pause.) Using ReaderWriterLock. I believe this would make things worse since the region being locked is small. Suggestions are very welcome.

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  • Most efficient way to make an activity log

    - by Nathan
    I am making a "recent activity" tab to profiles on my site and I also am going to have a log for moderators to see everything that happens on the site. This would require making an activity log of some sort. I just don't know what would be better. I have 2 options: Make a table called "activity" and then every time someone does something, add a record to it with the type of action, user id, timestamp, etc. Problem: table could get very long. Join all 3 tables (questions, answers, answer_comments) and then somehow show all these on the page in the order in which the action was taken. Problem: this would be extremely hard because I have no clue how I could make it say "John commented on an answer on Question Title Here" by just joining 3 tables. Does anyone know of a better way of making an activity log in this situation? I am using PHP and MySQL. If this is either too inefficient or hard I will probably just forget the Recent Activity tab on profiles but I still need an activity log for moderators. Here's some SQL that I started making for option 2, but this would not work because there is no way of detecting whether the action is a comment, question, or answer when I echo the info in a while loop: SELECT q.*, a.*, ac.* FROM questions q JOIN answers a ON a.questionid = q.qid JOIN answer_comments ac ON c.answerid = a.ans_id WHERE q.user = $userid AND a.userid = $userid AND ac.userid = $userid ORDER BY q.created DESC, a.created DESC, ac.created DESC Thanks in advance for any help!

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  • Postgres error with Sinatra/Haml/DataMapper on Heroku

    - by sevennineteen
    I'm trying to move a simple Sinatra app over to Heroku. Migration of the Ruby app code and existing MySQL database using Taps went smoothly, but I'm getting the following Postgres error: PostgresError - ERROR: operator does not exist: text = integer LINE 1: ...d_at", "post_id" FROM "comments" WHERE ("post_id" IN (4, 17,... ^ HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts. It's evident that the problem is related to a type mismatch in the query, but this is being issued from a Haml template by the DataMapper ORM at a very high level of abstraction, so I'm not sure how I'd go about controlling this... Specifically, this seems to be throwing up on a call of p.comments from my Haml template, where p represents a given post. The Datamapper models are related as follows: class Post property :id, Serial ... has n, :comments end class Comment property :id, Serial ... belongs_to :post end This works fine on my local and current hosted environment using MySQL, but Postgres is clearly more strict. There must be hundreds of Datamapper & Haml apps running on Postgres DBs, and this model relationship is super-conventional, so hopefully someone has seen (and determined how to fix) this. Thanks!

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  • Someone selling my GPL theme

    - by PaKK
    I'm having a tough time trying to figure out the best way to handle this. I've created a few themes last year, released them under a GPL license, and pretty much forgot about them. My goal was to put them out publicly as samples of my work. I've recently come across a site and was shocked they are selling one of my themes among several other themes (not mine) and other support and package systems. Anyway needless to say I'm not happy about this. I did not intend for those themes to be sold, and if they are to be sold, at least I would expect a percentage of those sales. I contacted the website asking how many they sold and that I'm the author of one of the themes they were selling. I eventually received a reply that my theme is a GPL theme and that this license allows them to sell it without compensation to me. WTF? Just the way the reply was worded pissed me off. There is no way to comment on the site to inform possible buyers that those themes can be downloaded from my site. What can I do about this? I realize now it was a bad choice to release them under that license. Is it possible to take back the theme from public distribution or is it out forever. Can I change it from GPL to another license at this point? Will that be sufficient to stop the sale of my theme in the future? Any insights are appreciated.

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  • UIAlertView choice causing resignFirstResponder to fail

    - by Chazbot
    Hi everyone. I'm having a similar issue to Anthony Chan's question, and after trying every suggested solution, I'm still stuck. Somehow, only after interacting with my UIAlertView, I'm unable to dismiss the keyboard in another view of my app. It's as though the Alert is breaking my UITextField's ability to resignFirstResponder. Below I instantiate my UIAlertView, which then calls its didDismissWIthButtonIndex method. Then, I call the showInfo method, which loads another UIViewController. UIAlertView *emailFailAlert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"error message text." delegate:self cancelButtonTitle:@"Not now" otherButtonTitles:@"Settings", nil]; [emailFailAlert setTag:2]; [emailFailAlert show]; [emailFailAlert release]; Once the 'Settings' option is pressed, I'm calling this method: - (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex { if ([alertView tag] == 2) { if (buttonIndex == 1){ [self showInfo:nil]; } } } My showInfo method loads the other ViewController, via the code below: - (IBAction)showInfo:(id)sender { FlipsideViewController *fscontroller = [[FlipsideViewController alloc] initWithNibName:@"FlipsideView" bundle:nil]; fscontroller.delegate = self; fscontroller.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal; [self presentModalViewController:fscontroller animated:YES]; [fscontroller release]; } Upon clicking any textField in this Flipside VC, I'm unable to dismiss the keyboard as I normally can with - (BOOL)textFieldShouldReturn:(UITextField *)textField, and [textField resignFirstResponder]. I've omitted this code bc this question is getting long, but I'm happy to post if necessary. The interesting part is that if I comment out the [self showInfo:nil] call made when the button is clicked and call it by clicking a test button (outside the alertView didDismissWithButtonIndex: method), everything works fine. Any idea what's happening here? Thanks in advance!

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