Search Results

Search found 13842 results on 554 pages for 'reference identity'.

Page 478/554 | < Previous Page | 474 475 476 477 478 479 480 481 482 483 484 485  | Next Page >

• Yet another question about C++ books..

  - by suicideducky

  Intro rant Hey all, so after just over a year of browsing I decided it's time to ask a question for myself, it's sadly similar to many that have been asked before. I'm 18, am studying towards a BSc in Comp SCi and have been programming 'on and off' for about 6 years now, after wrestling with C++ for a bit then stumbling upon (and reading cover to cover) "Programming: Principles and Practice Using C++" by the great man himself I feel pretty comfortable with C++, I am almost finished writing my first open source program in C++ (a mediawiki parser, http://code.google.com/p/apertium-mediawiki/). I have decided I want to really get to know the power of C++, get familiar with some of its 'darker' corners and also delve into game programming, at this point I am rather keen on the book "Essential 3D Game Programming: with C++ and OpenGL" (released 24 may '10), I would also like to get 1 or 2 other books on 'general C++' that I can read cover to cover during my spare time. At this point I am pretty open to suggestions I would like something in the intermediate/advanced zone, some books I am rather keen on include: The C++ Standard Library: A tutorial and reference, C++ Template, the complete guide, and Modern C++ Design: Generic Programming and Design Patterns Applied Thanks in advance.

  Read the article

• How to give user confirmation message before ActionLink based on validation

  - by RememberME

  I have the following link. On click, I'd like to check the item.primary_company field and if populated, give the user a warning and ask if they would like to continue. How can I do this? <a href="<%= Url.Action("Activate", new {id = item.company_id}) %>" class="fg=button fg-button-icon-solo ui-state-default ui-corner-all"><span class="ui-icon ui-icon-refresh"></span></a> EDIT I've changed to this, but nothing happens when clicked. Also, I don't know how to reference the item to do the check on the primary_company field. I only want to message to show if item.primary_company.HasValue. I'd also like to show item.company1.company_name in the confirm message. <a href="#" onclick="return Actionclick("<%= Url.Action("Activate", new {id = item.company_id}) %>");" class="fg=button fg-button-icon-solo ui-state-default ui-corner-all"><span class="ui-icon ui-icon-refresh"></span></a> <script type="text/javascript"> function Actionclick(url) { alert("myclick"); if ( confirm("Do you want to activate this company's primary company and all other subsidiaries?")) { location.href(url); } }; </script>

  Read the article

• How can this Ambient Context become null?

  - by Mark Seemann

  Can anyone help me explain how TimeProvider.Current can become null in the following class? public abstract class TimeProvider { private static TimeProvider current = DefaultTimeProvider.Instance; public static TimeProvider Current { get { return TimeProvider.current; } set { if (value == null) { throw new ArgumentNullException("value"); } TimeProvider.current = value; } } public abstract DateTime UtcNow { get; } public static void ResetToDefault() { TimeProvider.current = DefaultTimeProvider.Instance; } } Observations All unit tests that directly reference TimeProvider also invokes ResetToDefault() in their Fixture Teardown. There is no multithreaded code involved. Once in a while, one of the unit tests fail because TimeProvider.Current is null (NullReferenceException is thrown). This only happens when I run the entire suite, but not when I just run a single unit test, suggesting to me that there is some subtle test interdependence going on. It happens approximately once every five or six test runs. When a failure occurs, it seems to be occuring in the first executed tests that involves TimeProvider.Current. More than one test can fail, but only one fails in a given test run. FWIW, here's the DefaultTimeProvider class as well: public class DefaultTimeProvider : TimeProvider { private readonly static DefaultTimeProvider instance = new DefaultTimeProvider(); private DefaultTimeProvider() { } public override DateTime UtcNow { get { return DateTime.UtcNow; } } public static DefaultTimeProvider Instance { get { return DefaultTimeProvider.instance; } } } I suspect that there's some subtle interplay going on with static initialization where the runtime is actually allowed to access TimeProvider.Current before all static initialization has finished, but I can't quite put my finger on it. Any help is appreciated.

  Read the article

• NHibernate Entity code conversion from #C to VB.Net

  - by CoderRoller

  Hello and thanks for your help in advance. I am starting on the NHibernate world and i am experimenting with the NHibernate CookBook recipes, i am trying to set a base entity class for my entities and this is the C# code for this. I would like to know whats the VB.NET version so i can implement it in my sample project. This is the C# code: public abstract class Entity<TId> { public virtual TId Id { get; protected set; } public override bool Equals(object obj) { return Equals(obj as Entity<TId>); } private static bool IsTransient(Entity<TId> obj) { return obj != null && Equals(obj.Id, default(TId)); } private Type GetUnproxiedType() { return GetType(); } public virtual bool Equals(Entity<TId> other) { if (other == null) return false; if (ReferenceEquals(this, other)) return true; if (!IsTransient(this) && !IsTransient(other) && Equals(Id, other.Id)) { var otherType = other.GetUnproxiedType(); var thisType = GetUnproxiedType(); return thisType.IsAssignableFrom(otherType) || otherType.IsAssignableFrom(thisType); } return false; } public override int GetHashCode() { if (Equals(Id, default(TId))) return base.GetHashCode(); return Id.GetHashCode(); } } I tried using an online converter but puts a Nothing reference in place of default(TId) that doesn't seem right to me that's why I request for help: Private Shared Function IsTransient(obj As Entity(Of TId)) As Boolean Return obj IsNot Nothing AndAlso Equals(obj.Id, Nothing) End Function I Would appreciate the insight you may give me on the subject.

  Read the article

• How do I delete duplicates between two excel sheets quickly vba

  - by MainTank

  I am using vba and I have two sheets one is named "Do Not Call" and has about 800,000 rows of data in column A. I want to use this data to check column I in the second sheet, named "Sheet1". If it finds a match I want it to delete the whole row in "Sheet1". I have tailored the code I have found from a similar question here: Excel formula to Cross reference 2 sheets, remove duplicates from one sheet and ran it but nothing happens. I am not getting any errors but it is not functioning. Here is the code I am currently trying and have no idea why it is not working Option Explicit Sub CleanDupes() Dim wsA As Worksheet Dim wsB As Worksheet Dim keyColA As String Dim keyColB As String Dim rngA As Range Dim rngB As Range Dim intRowCounterA As Integer Dim intRowCounterB As Integer Dim strValueA As String keyColA = "A" keyColB = "I" intRowCounterA = 1 intRowCounterB = 1 Set wsA = Worksheets("Do Not Call") Set wsB = Worksheets("Sheet1") Dim dict As Object Set dict = CreateObject("Scripting.Dictionary") Do While Not IsEmpty(wsA.Range(keyColA & intRowCounterA).Value) Set rngA = wsA.Range(keyColA & intRowCounterA) strValueA = rngA.Value If Not dict.Exists(strValueA) Then dict.Add strValueA, 1 End If intRowCounterA = intRowCounterA + 1 Loop intRowCounterB = 1 Do While Not IsEmpty(wsB.Range(keyColB & intRowCounterB).Value) Set rngB = wsB.Range(keyColB & intRowCounterB) If dict.Exists(rngB.Value) Then wsB.Rows(intRowCounterB).delete intRowCounterB = intRowCounterB - 1 End If intRowCounterB = intRowCounterB + 1 Loop End Sub I apologize if the above code is not in a code tag. This is my first time posting code online and I have no idea if I did it correctly.

  Read the article

• Django: Storing ordered, arbitrary references

  - by Sarah

  I'm new to Django, and I'm not sure what I want is possible: I have a number of items that I want each AppUser (extended User model) to be able to reference. That is, given an AppUser, I want to be able to extract its list of items in the way that AppUser has chosen to order them. In general, these items would actually be references to something else in the database, and this led me to one possible solution: Store the keys for the given objects in a CommaSeparatedIntegerField in AppUser. This way, a user could have stored {7, 3, 232, 42, 1} in their items field and both the references and their preferred order would be stored. However, this feels hacky. Since most db backends store CommaSeparatedIntegerField as a VARCHAR internally, the user is not only limited by a number of objects, but also the number of digits in their chosen items. Eg. "you may store 10 items if you choose items with itemID < 10, but only 5 items if 10 < itemID < 100". Is there a better way to do this?

  Read the article

• JQuery to PHP function and back Ajaxed

  - by Xaris

  Hi all, i have a set of php function that i want to call on different events mostly onclick with jquery async (ajax). The first function is called on load $(document).ready(function() { $("#div2").hide('slow'); $("#div1").empty().html('<img src="ajax-loader.gif" />'); $.ajax( { type: "POST", url: "WebFunctions.php", data: {'func':'1'}, success: function(html) { $("#div1").show('slow').html(html) } }); The Data: {'func':'1'} -- is a switch statement on the php side switch($_POST['func']) { case '1': getParents(); break; case '2': getChilds(params); break; case '3': getChildObjects(params); break; default: } "This functions are calls to a soap server" <-- irrelevant. So when that function finishes i get an array which contains IDs and Names. I echo the names but i want the ID for reference so when i click on the echoed name i can call an other php function with parameter the ID of the name... How do i get rid of the switch statement?? How do i call properly php functions and pass params to it??? How can i save this IDs so when i click on an item with that id an other php function is called?? Plz feel free to ask any question, any answer is welcome :)

  Read the article

• Optimizing C++ Tree Generation

  - by cam

  Hi, I'm generating a Tic-Tac-Toe game tree (9 seconds after the first move), and I'm told it should take only a few milliseconds. So I'm trying to optimize it, I ran it through CodeAnalyst and these are the top 5 calls being made (I used bitsets to represent the Tic-Tac-Toe board): std::_Iterator_base::_Orphan_me std::bitset<9::test std::_Iterator_base::_Adopt std::bitset<9::reference::operator bool std::_Iterator_base::~_Iterator_base void BuildTreeToDepth(Node &nNode, const int& nextPlayer, int depth) { if (depth > 0) { //Calculate gameboard states int evalBoard = nNode.m_board.CalculateBoardState(); bool isFinished = nNode.m_board.isFinished(); if (isFinished || (nNode.m_board.isWinner() > 0)) { nNode.m_winCount = evalBoard; } else { Ticboard tBoard = nNode.m_board; do { int validMove = tBoard.FirstValidMove(); if (validMove != -1) { Node f; Ticboard tempBoard = nNode.m_board; tempBoard.Move(validMove, nextPlayer); tBoard.Move(validMove, nextPlayer); f.m_board = tempBoard; f.m_winCount = 0; f.m_Move = validMove; int currPlay = (nextPlayer == 1 ? 2 : 1); BuildTreeToDepth(f,currPlay, depth - 1); nNode.m_winCount += f.m_board.CalculateBoardState(); nNode.m_branches.push_back(f); } else { break; } }while(true); } } } Where should I be looking to optimize it? How should I optimize these 5 calls (I don't recognize them=.

  Read the article

• Page Entirely Blank Despite Having Source Code! (TinyMCE, FireFox)

  - by Chris Cooper

  Alright guys, here's a tough one... In reference to this page. The page will seemingly randomly not display the output of server when using Firefox (version 3.5). I have not seen this problem occur in Safari or IE. The best way to have the problem occur is just reload the page about 10 times and it ought to have happened by then, and once it does - it'll continue on subsequent refreshes until you change the page. The problem is literally the browser not displaying the output (code). Viewing the source shows all the appropriate code yet the browser displays a blank white page. The web developer and firebug plugins don't show any errors that would indicate the problem. I have tested this on a separate system and OS and it occurs in Firefox on that system as well. The problem did not occur until after TinyMCE (A Rich Text Editor JavaScript library for textareas) was added to the project. TinyMCE works however, where it should. I know this is a confusing problem, but I am completely lost as to what could be causing this significant issue. Thanks in advance. EDIT: If it's any help... I've noticed that if I cause a css file error by changing a stylesheet source to something non-existant (xxx.css), the page will continuously display without a problem (besides whatever related css not showing due to the src change). I've also noticed that causing any simple javascript error with some bad code will cause the page to load properly continuously (besides of course javascript not running on the page). EDIT#2: Moving all <script> tags down at the tail of the <body> 'fixes' (well, hides) this error and the page shows normally. A band-aid.

  Read the article

• Doctrine YAML not generating correctly? Or is this markup wrong?

  - by ropstah

  I'm trying to get a many-to-many relationship between Users and Settings. The models seem to be generated correctly, however the following query fails: "User_Setting" with an alias of "us" in your query does not reference the parent component it is related to. $q = new Doctrine_RawSql(); $q->select('{s.*}, {us.*}') ->from('User u CROSS JOIN Setting s LEFT JOIN User_Setting us ON us.usr_auto_key = u.usr_auto_key AND us.set_auto_key = s.set_auto_key') ->addComponent('s', 'Setting s INDEXBY s.set_auto_key') ->addComponent('us', 'User_Setting us') ->where(u.usr_auto_key = ?',$this->usr_auto_key); $this->settings = $q->execute(); Does anyone spot a problem? This is my YAML: User: connection: default tableName: User columns: usr_auto_key: type: integer(4) fixed: false unsigned: false primary: true autoincrement: true notnull: true email: type: string(100) fixed: false unsigned: false primary: false default: '' notnull: true autoincrement: false password: type: string(32) fixed: false unsigned: false primary: false default: '' notnull: true autoincrement: false relations: Setting: class: Setting foreignAlias: User refClass: User_Setting local: usr_auto_key foreign: set_auto_key Setting: connection: default tableName: Setting columns: set_auto_key: type: integer(4) fixed: false unsigned: false primary: true autoincrement: true notnull: true name: type: string(50) fixed: false unsigned: false primary: false notnull: true autoincrement: false User_Setting: connection: default tableName: User_Setting columns: usr_auto_key: type: integer(4) fixed: false unsigned: false primary: true autoincrement: false notnull: true set_auto_key: type: integer(4) fixed: false unsigned: false primary: true autoincrement: false notnull: true value: type: string(255) fixed: false unsigned: false primary: false notnull: true autoincrement: false relations: Setting: foreignAlias: User_Setting local: set_auto_key foreign: set_auto_key User: foreignAlias: User_Setting local: usr_auto_key foreign: usr_auto_key

  Read the article

• Handling primary key duplicates in a data warehouse load

  - by Meff

  I'm currently building an ETL system to load a data warehouse from a transactional system. The grain of my fact table is the transaction level. In order to ensure I don't load duplicate rows I've put a primary key on the fact table, which is the transaction ID. I've encountered a problem with transactions being reversed - In the transactional database this is done via a status, which I pick up and I can work out if the transaction is being done, or rolled back so I can load a reversal row in the warehouse. However, the reversal row will have the same transaction ID and so I get a primary key violation. I've solved this for now by negating the primary key, so transaction ID 1 would be a payment, and transaction ID -1 (In the warehouse only) would be the reversal. I have considered an alternative of generating a BIT column, where 0 is normal and 1 is reversal, then making the PK the transaction ID and the BIT column. My question is, is this a good practice, and has anyone else encountered anything like this? For reference, this is a payment processing system, so values will not be modified, so there will only ever be transactions and reversals.

  Read the article

• C++ universal data type

  - by Gokul

  I have a universal data type, which is passed by value, but does not maintain the type information. We store only pointers and basic data types(like int, float etc) inside this. Now for the first time, we need to store std::string inside this. So we decided to convert it into std::string* and store it. Then comes the problem of destruction. We don't like to copy the std::string every time. So i am thinking of an approach like this. Say the data type looks like this class Atom { public : enum flags { IS_STRING, IS_EMPTY, HAS_GOT_COPIED, MARKER }; private: void* m_value; std::bitset<MARKER> m_flags; public: ..... Atom( Atom& atm ) { atm.m_flags.set( HAS_GOT_COPIED ); ..... } ..... ~Atom() { if( m_flags.test(IS_STRING) && !m_flags.test(HAS_GOT_COPIED) ) { std::string* val = static_cast<std::string*>(m_value); delete val; } } }; Is this a good approach to find out whether there is no more reference to std::string*? Any comments.. Thanks, Gokul.

  Read the article

• What am I doing wrong with SVN merging?

  - by randomusername

  When SVN with merge tracking works, it's really nice, I love it. But it keeps getting twisted up. We are using TortoiseSVN. We continuously get the following message: Error: Reintegrate can only be used if revisions 1234 through 2345 were previously merged from /Trunk to the reintegrate source, but this is not the case For reference, this is the method we are using: Create a Branch Develop in the branch Occasionally Merge a range of revisions from the Trunk to the Branch When branch is stable, Reintegrate a branch from the branch to the trunk Delete the branch I Merge a range of revisions from the trunk to the branch (leaving the range blank, so it should be all revisions) just prior to the reintegrate operation, so the branch should be properly synced with the trunk. Right now, the Trunk has multiple SVN merge tracking properties associated with it. Should it? Or should a Reintegrate not add any merge tracking info? Is there something wrong with our process? This is making SVN unusable - 1 out of every 3 reintegrates forces me to dive in and hack at the merge tracking info.

  Read the article

• How to add a hierarchical tag in an XML file though XSL?

  - by Hetal

  Hello, I am facing a problem in XML transformation. Sorry if the question is asked before. The XML tag hierarchy is as follows: //This tag contains the header data (Example:Pick Slip Number) Then the Detail lines are printed. The detail lines are printed. This detail line belongs to the previous Pick Slip Number. The detail lines are printed. This detail line belongs to the previous Pick Slip Number. My requirement is to: //This tag contains the header data (Example:Pick Slip Number) Then the Detail lines are printed. The detail lines are printed. This detail line belongs to the previous Pick Slip Number. The detail lines are printed. This detail line belongs to the previous Pick Slip Number. My requirement is to print the Pick Slip Number at every page on the header. Since there is no parent tag for and , I face the problem while printing. I am trying to serach something in XML transformation. But I dont know how to transform the XML tag hierarchy. I have attached the XML file for the reference. Thanks..

  Read the article

• How to structure code with 2 methods, one after another, which throw the same two exceptions?

  - by dotnetdev

  Hi, I have two methods, one called straight after another, which both throw the exact same 2 exceptions (IF an erroneous condition occurs, not stating that I'm getting exceptions). For this, should I write seperate try and catch blocks with the one statement in each try block and catch both exceptions (Both of which I can handle as I checked MSDN class library reference and there is something I can do, eg, re-open SqlConnection or run a query and not a stored proc which does not exist). So code like this: try { obj.Open(); } catch (SqlException) { // Take action here. } catch (InvalidOperationException) { // Take action here. } And likewise for the other method I call straight after. This seems like a very messy way of coding. The other way is to code with the exception variable (that is ommited as I am using AOP to log the exception details, using a class-level attribute). Doing this, this could aid me in finding out which method caused an exception and then taking action accordingly. Is this the best approach or is there another best practise altogether? I also assume that, as only these two methods are thrown, I do not need to catch Exception as that would be for an exception I cannot handle (causes way out of my control). Thanks

  Read the article

• Web service failing when installed in seperate project from the website...

  - by Adam

  I am totally new to web services and cannot get mine to work. My setup is on VS 2008 using IIS. I have one solution file with 3 projects in it: website, code, and services. If I put my webservice into my website and call it locally then it will work fine (it's just a hello world web service). I want to put the service into a different location for use from multiple sites. I don't know what I'm doing wrong - i've read so much conflicting info regarding disco files, access files, silverlight, flash, java, etc. I just looking for quick simple steps to create a web service that I can access from javascript and deploy to a seperate website. End goal is to have functionality in webservices so that website will call via JS and run much smoother in the loading time and async calls. Do I need to create a disco file? Do I need to configure security? -- I know this is prob best, i'm just looking to get it working at all. Do I need to allow cross browser access on IIS or on my hosted server? Are there any quick reference websites that you can recommend? Should I be using WCF as new technology? - I saw this on MSDN but seems to be more for windows apps then web apps. I'm not getting any specific error codes. I have installed the firefox debugging tools (firebug) and I can see what the headers are but I don't know how to interpret them and there is no response being passed back. Any help is appreciated!!!

  Read the article

• Detecting what the target object is when NullReferenceException is thrown.

  - by StingyJack

  I'm sure we all have received the wonderfully vague "Object reference not set to instance of an Object" exception at some time or another. Identifying the object that is the problem is often a tedious task of setting breakpoints and inspecting all members in each statement. Does anyone have any tricks to easily and efficiently identify the object that causes the exception, either via programmatical means or otherwise? --edit It seems I was vague like the exception =). The point is to _not have to debug the app to find the errant object. The compiler/runtime does know that the object has been allocated, and that the object has not yet been instantiated. Is there a way to extract / identify those details in a caught exception @ W. Craig Trader Your explanation that it is a result of a design problem is probably the best answer I could get. I am fairly compulsive with defensive coding and have managed to get rid of most of these errors after fixing my habits over time. The remaining ones just tweak me to no end, and lead me to posting this question to the community. Thanks for everyone's suggestions.

  Read the article

• Get element id on hover (or mouseover)

  - by Peter C

  Still getting to grips with jQuery and I am pleased to have got as far as I have, especially help from the posts in this forum. However, now got to a working function that does what I want, that is to create a radio group that looks like a button. It pulls data via json and loops through creating the radio buttons. I want to get the id of the radio buttons generated so that I can then parse through to the next step of the app but I can't get it to work. function FillDiv(groups, side) { var cnt = 1; var newClass = ''; var newType = ''; if (side == '#ck-button-left') { newClass = 'leftClass'; newType = 'radio' } else { newClass = 'rightClass'; newType = 'checkbox' } $.each(groups, function (index, groups) { $(side) .append( $(document.createElement('label')).attr({ id: cnt + 'lbl' }) ); $('#' + cnt + 'lbl') .append( $(document.createElement('input')).attr({ id: groups.GroupCode, type: newType, name: 'testGroup', class: newClass }) ); $('#' + groups.GroupCode).after ( $(document.createElement('span')).text(groups.GroupName).attr('class', 'leftSpan') ); $('#' + cnt + 'lbl').after($(document.createElement('br'))); cnt = cnt + 1; }); } Looking through various searched, it should work with something like... $('#leftSpan').mouseover(function () { $('#lblOutput').html(this.id); }); or, as I suspect, it is something to do with the nesting of the label/input that I need to reference the parent or child. Any pointers would be appreciated.

  Read the article

• How to make 2 incompatible types, but with the same members, interchangeable?

  - by Quigrim

  Yesterday 2 of the guys on our team came to me with an uncommon problem. We are using a third-party component in one of our winforms applications. All the code has already been written against it. They then wanted to incorporate another third-party component, by the same vender, into our application. To their delight they found that the second component had the exact same public members as the first. But to their dismay, the 2 components have completely separate inheritance hierarchies, and implement no common interfaces. Makes you wonder... Well, makes me wonder. An example of the problem: public class ThirdPartyClass1 { public string Name { get { return "ThirdPartyClass1"; } } public void DoThirdPartyStuff () { Console.WriteLine ("ThirdPartyClass1 is doing its thing."); } } public class ThirdPartyClass2 { public string Name { get { return "ThirdPartyClass2"; } } public void DoThirdPartyStuff () { Console.WriteLine ("ThirdPartyClass2 is doing its thing."); } } Gladly they felt copying and pasting the code they wrote for the first component was not the correct answer. So they were thinking of assigning the component instant into an object reference and then modifying the code to do conditional casts after checking what type it was. But that is arguably even uglier than the copy and paste approach. So they then asked me if I can write some reflection code to access the properties and call the methods off the two different object types since we know what they are, and they are exactly the same. But my first thought was that there goes the elegance. I figure there has to be a better, graceful solution to this problem.

  Read the article

• Database PK-FK design for future-effective-date entries?

  - by Scott Balmos

  Ultimately I'm going to convert this into a Hibernate/JPA design. But I wanted to start out from purely a database perspective. We have various tables containing data that is future-effective-dated. Take an employee table with the following pseudo-definition: employee id INT AUTO_INCREMENT ... data fields ... effectiveFrom DATE effectiveTo DATE employee_reviews id INT AUTO_INCREMENT employee_id INT FK employee.id Very simplistic. But let's say Employee A has id = 1, effectiveFrom = 1/1/2011, effectiveTo = 1/1/2099. That employee is going to be changing jobs in the future, which would in theory create a new row, id = 2 with effectiveFrom = 7/1/2011, effectiveTo = 1/1/2099, and id = 1's effectiveTo updated to 6/30/2011. But now, my program would have to go through any table that has a FK relationship to employee every night, and update those FK to reference the newly-effective employee entry. I have seen various postings in both pure SQL and Hibernate forums that I should have a separate employee_versions table, which is where I would have all effective-dated data stored, resulting in the updated pseudo-definition below: employee id INT AUTO_INCREMENT employee_versions id INT AUTO_INCREMENT employee_id INT FK employee.id ... data fields ... effectiveFrom DATE effectiveTo DATE employee_reviews id INT AUTO_INCREMENT employee_id INT FK employee.id Then to get any actual data, one would have to actually select from employee_versions with the proper employee_id and date range. This feels rather unnatural to have this secondary "versions" table for each versioned entity. Anyone have any opinions, suggestions from your own prior work, etc? Like I said, I'm taking this purely from a general SQL design standpoint first before layering in Hibernate on top. Thanks!

  Read the article

• Can a member struct be zero-init from the constructor initializer list without calling memset?

  - by selbie

  Let's say I have the following structure declaration (simple struct with no constructor). struct Foo { int x; int y; int z; char szData[DATA_SIZE]; }; Now let's say this struct is a member of a C++ class as follows: class CFoobar { Foo _foo; public: CFoobar(); }; If I declare CFoobar's constructor as follows: CFoobar::CFoobar() { printf("_foo = {%d, %d, %d}\n", _foo.x, _foo.y,_foo.z); for (int x = 0; x < 100; x++) printf("%d\n", _foo.szData[x]); } As you would expect, when CFoobar's constructor runs, garbage data gets printed out Obviously, the easy fix is to memset or ZeroMemory &_foo. It's what I've always done... However, I did notice that if add _foo to the constructor's initialization list with no parameters as follows: CFoobar::CFoobar() : _foo() { That this appears to zero-out the member variables of _foo. At least that was the case with g++ on linux. Now here's my question: Is this standard C++, or is this compiler specific behavior? If it's standard behavior, can someone quote me a reference from an official source? Any "gotchas" in regards to implicit zero-init behavior with more complicated structs and classes?

  Read the article

• Help with simple javascript loop

  - by Gabriel

  Hello, I have a simple javascript that I'd like to loop for multiple elements. Here's my code: <script type='text/javascript'> for(i = 1; i < 100; i++) { $('#link'+i).click(function() { $('#container').removeClass(); $('#container').addClass('templateid'+i); }); } </script> What I'd like to achieve is the same addClass function for multiple id's (e.g. link2, link3, link4), with the corresponding class (e.g. template2, template3, template4). Any help would be hugely appreciated! For reference, an individual call like this one, does work, so I don't see why the loop above doesn't function the same: <script type='text/javascript'> $('#link2').click(function() { $('#container').removeClass(); $('#container').addClass('templateid2'); }); </script>

  Read the article

• How to know the type of an object in a list?

  - by nacho4d

  Hi, I want to know the type of object (or type) I have in my list so I wrote this: void **list; //list of references list = new void * [2]; Foo foo = Foo(); const char *not_table [] = {"tf", "ft", 0 }; list[0] = &foo; list[1] = not_table; if (dynamic_cast<LogicProcessor*>(list[0])) { //ERROR here ;( printf("Foo was found\n"); } if (dynamic_cast<char*> (list[0])) { //ERROR here ;( printf("char was found\n"); } but I get : error: cannot dynamic_cast '* list' (of type 'void*') to type 'class Foo*' (source is not a pointer to class) error: cannot dynamic_cast '* list' (of type 'void*') to type 'char*' (target is not pointer or reference to class) Why is this? what I am doing wrong here? Is dynamic_cast what I should use here? Thanks in advance EDIT: I know above code is much like plain C and surely sucks from the C++ point of view but is just I have the following situation and I was trying something before really implementing it: I have two arrays of length n but both arrays will never have an object at the same index. Hence, or I have array1[i]!=NULL or array2[i]!=NULL. This is obviously a waste of memory so I thought everything would be solved if I could have both kind of objects in a single array of length n. I am looking something like Cocoa's (Objective-C) NSArray where you don't care about the type of the object to be put in. Not knowing the type of the object is not a problem since you can use other method to get the class of a certain later. Is there something like it in c++ (preferably not third party C++ libraries) ? Thanks in advance ;)

  Read the article

• Static selection and Ruby on Rails objects

  - by Dave

  Hi all- I have a simple problem, but am having trouble wrapping my head around it. I have an video object that should have one or more "genres". This list of genres should be prepopulated and then the user should just select one or more using autocomplete or some such. Here is the question: Is it worth creating a table with genres for the static selection? Or should it just be included in the presentation layer? If there is a static table, how do we name it correctly. I envision something like this class Video < ActiveRecord::Base has_many :genres ... end class Genre < ... belongs_to :video ... end But then we get a table called genre, that basically maps all the selected genres to their parent videos. There would need to be some static table to reference the static genres. Is this the best way to do it? Sorry if this was rambl-y a little stream of conciousness. Thanks!

  Read the article

• Is it possible to aggregate over differing where clauses?

  - by BenAlabaster

  Is it possible to calculate multiple aggregates based on differing where clauses? For instance: Let's say I have two tables, one for Invoice and one for InvoiceLineItems. The invoice table has a total field for the invoice total, and each of the invoice line item records in the InvoiceLineItems table contains a field that denotes whether the line item is discountable or not. I want three sum totals, one where Discountable = 0 and one where Discountable = 1 and one where Discountable is irrelevant. Such that my output would be: InvoiceNumber Total DiscountableTotal NonDiscountableTotal ------------- ----- ----------------- -------------------- 1 53.27 27.27 16.00 2 38.94 4.76 34.18 3... The only way I've found so far is by using something like: Select i.InvoiceNumber, i.Total, t0.Total As DiscountableTotal, t1.Total As NonDiscountableTotal From Invoices i Left Join ( Select InvoiceNumber, Sum(Amount), From InvoiceLineItems Where Discountable = 0 Group By InvoiceNumber ) As t0 On i.InvoiceNumber = t0.InvoiceNumber Left Join ( Select InvoiceNumber, Sum(Amount) From InvoiceLineItems Where Discountable = 1 Group By InvoiceNumber ) As t1 On i.InvoiceNumber = t1.InvoiceNumber This seems somewhat cumbersome, it would be nice if I could do something like: Select InvoiceNumber, Sum(Amount) Where Discountable = 1 As Discountable Sum(Amount) Where Discountable = 0 As NonDiscountable Group By InvoiceNumber I realize that SQL is completely invalid, but it logically portrays what I'm trying to do... TIA P.S. I need this to run on a SQL Server 2000 instance, but I am also interested (for future reference) if/how I would achieve this on SQL Server 2005/2008.

  Read the article

< Previous Page | 474 475 476 477 478 479 480 481 482 483 484 485  | Next Page >