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  • ruby on rails group by with null values problem

    - by winter sun
    I have an hour table in witch I store user time tracking information, the table consists from the following cells project_id task_id (optional can be null) worker_id reported_date working_hours each worker enters sevral records per day so generally the table is looking like this id project_id worker_id task_id reported_date working hours; == =========== ========= ========= ============= ============== 1 1 1 1 10/10/2011 4 2 1 1 1 10/10/2011 14 3 1 1 10/10/2011 4 4 1 1 10/10/2011 14 the task_id is not a must field so there can be times when the user is not selecting it and ther task_id cell is empty now i need to display the data by using group by clouse so the resualt will be somthing like this project_id worker_id task_id working hours ========== ========= ========= ============== 1 1 1 18 1 1 18 I did the folowing group by condition @group_hours=Hour.group('project_id,worker_id,task_id)').select('project_id, task_id ,worker_id,sum(working_hours)as working_hours_sum') My view looks like this <% @group_hours.each do |b| % <%= b.project.name if b.project % <%= b.worker.First_name if b.worker % <%= b.task.name if b.task % <%= b.working_hours_sum % <%end% This it is working but only if the task_id is not null when task id is null it present all the records without grouping them like this project_id worker_id task_id working hours =========== ========= ========= ============== 1 1 1 18 1 1 4 1 1 14 I will appreciate any kind of solution to this problem

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  • Geolocation Null in lat and long

    - by user1706989
    I have had issue today in one application where Geolocation is not working. Even on this page http://slaveryfootprint.org/survey/#where_do_you_live . When you enter a location , its showing null lattiude and longitude. Even though it search for autolocation, it can point the right location. and it happened all if a sudden today which was working fine since yestrday night and when I see in console it is returning null lat and long and null for city and I did not change the code at all. Did google map api changed something. or do I need to update jquery? http://maps.google.com/maps/api/js?v=3.4&sensor=false

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  • linq NullReferenceException while checking for null reference

    - by Odrade
    I have the following LINQ query: List<FileInputItem> inputList = GetInputList(); var results = from FileInputItem f in inputList where ( Path.GetDirectoryName(f.Folder).ToLower().Trim() == somePath || Path.GetDirectoryName(f.Folder).ToLower().Trim() == someOtherPath ) && f.Expression == null select f; Every time this query is executed, it generates a NullReferenceException. If I remove the condition f.Expression == null or change it to f.Expression != null, the query executes normally (giving the wrong results, of course). The relevant bits of FileInputItem look like this: [Serializable] public class FileInputItem { [XmlElement("Folder")] public string Folder { get; set; } [XmlElement("Expression")] public string Expression { get; set; } /*SNIP. Irrelevant properties */ } I'm new to LINQ to objects, so I'm probably missing something fundamental here. What's the deal?

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  • flex/actionscript assignment failing?

    - by user346713
    I'm seeing something weird in my actionscript code I have two classes foo and bar, bar extends foo. In a model class I have a foo member variable, I assign an bar object to the foo variable. But after the assignment the foo variable is null. [Bindable] public var f:foo; public function someFunc(arr:ArrayCollection):void { if(arr.length > 0) { var tempBar:bar = arr.getItemAt(0) as bar; if(tempBar != null) { tempBar.someProp++; f = tempBar; // f is now null } } } Any ideas on what I could be doing wrong?

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  • Linq To Sql Left outer join - filtering null results

    - by Harry
    I'd like to reproduce the following SQL into C# LinqToSql SELECT TOP(10) Keywords.* FROM Keywords LEFT OUTER JOIN IgnoreWords ON Keywords.WordID = IgnoreWords.ID WHERE (DomainID = 16673) AND (IgnoreWords.Name IS NULL) ORDER BY [Score] DESC The following C# Linq gives the right answer. But I can't help think I'm missing something (a better way of doing it?) var query = (from keyword in context.Keywords join ignore in context.IgnoreWords on keyword.WordID equals ignore.ID into ignored from i in ignored.DefaultIfEmpty() where i == null where keyword.DomainID == ID orderby keyword.Score descending select keyword).Take(10); the SQL produced looks something like this: SELECT TOP (10) [t0].[DomainID], [t0].[WordID], [t0].[Score], [t0].[Count] FROM [dbo].[Keywords] AS [t0] LEFT OUTER JOIN (SELECT 1 AS [test], [t1].[ID] FROM [dbo].[IgnoreWords] AS [t1]) AS [t2] ON [t0].[WordID] = [t2].[ID] WHERE ([t0].[DomainID] = 16673) AND ([t2].[test] IS NULL) ORDER BY [t0].[Score] DESC How can I get rid of this redundant inner selection? It's only slightly more expensive but every bit helps!

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  • @OneToOne and @JoinColumn, auto delete null entity , doable?

    - by smallufo
    I have two Entities , with the following JPA annotations : @Entity @Table(name = "Owner") public class Owner implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name = "id") private long id; @OneToOne(fetch=FetchType.EAGER , cascade=CascadeType.ALL) @JoinColumn(name="Data_id") private Data Data; } @Entity @Table(name = "Data") public class Data implements Serializable { @Id private long id; } Owner and Data has one-to-one mapping , the owning side is Owner. The problem occurs when I execute : owner.setData(null) ; ownerDao.update(owner) ; The "Owner" table's Data_id becomes null , that's correct. But the "Data" row is not deleted automatically. I have to write another DataDao , and another service layer to wrap the two actions ( ownerDao.update(owner) ; dataDao.delete(data); ) Is it possible to make a data row automatically deleted when the owning Owner set it to null ?

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  • concatenating results from SQL query and NULL columns

    - by Curtis
    I need to concatenate several columns of a table into a single value, then show that value in an asp dropdownlist. The SQL code I'm issuing is as follows: SELECT UserID, CustomerNum, UserName + ' - ' + UserAddress + ',' + UserCity + ' ' + UserState AS UserInfo FROM Users WHERE (CustomerNum = @CustomerNum) ORDER BY UserName I then set 'UserInfo' as the text field in the dropdownlist. This generally works, except occasionally one of the columns in the database is null (for example, UserState). When that happens, the entire concatenation is null, and I get an empty entry in the dropdownlist. Is there something in SQLServer that will allow me to ignore those NULL results, or will I have to code something up in the DataBind event? Thanks

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  • nullable type and a ReSharper warning

    - by Sarah Vessels
    I have the following code: private static LogLevel? _logLevel = null; public static LogLevel LogLevel { get { if (!_logLevel.HasValue) { _logLevel = readLogLevelFromFile(); } return _logLevel.Value; } } private static LogLevel readLogLevelFromFile() { ... } I get a ReSharper warning on the return statement about a possible System.InvalidOperationException and it suggests I check _logLevel to see if it is null first. However, readLogLevelFromFile returns LogLevel, not LogLevel?, so there is no way the return statement could be reached when _logLevel is null. Is this just an oversight by ReSharper, or am I missing something?

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  • IEnumerable not null but calling Count() results in Exception

    - by Draak
    I have code that's working beautifully on my development machine, but when deployed to the server is throwing null reference exception. So, I can't step through the code, but I've pinned down the culprit. But now I am puzzled. Here's the code. The question is below. Dim certs = From p In persons _ Select New Certificate( _ p.Value, _ New CertificateData.Seminar(thisEvent.Seminar.Name, _ thisEvent.StartDate.Value, _ thisEvent.EndDate.Value, _ thisEvent.Venue.City, _ thisEvent.Venue.State, _ New CertificateData.Instructor( _ staffMember.Name, _ staffMember.Titles, _ instrSignatPath))) _ With {.CertificateId = p.Key} lblMessage.Text = CStr(certs Is Nothing) lblMessage.Text = lblMessage.Text + "<br />" + CStr(certs.Count()) In the code above persons is a dictionary of custom class, and certs is of IEnumerable type. Now here's the quandary.. The first line that sets the label returns False, so certs is not null. But the second line throws an null reference exception. How is this possible?

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  • When can argv[0] have null ?

    - by andrew-dufresne
    What I have understand about passing arguments to main() from command line is that argc has a minimum value of 1 and argv[0] will always have the program name with its path in it. If arguments are provided at the command line, then argc will have a value greater than one and argv1 to argv[argc-1] will have those arguments. Now a paragraph at this link says that argv[0] will be a string containing the program's name or a null string if that is not available. Now, how and when can argv[0] have null string? I mean program name with its path will always be available so when can it be null? Writer says that "if that is not available" but when and how it is possible that program name will not be available? Thanks for your time and support. Regards

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  • (this == null) in C#!

    - by SLaks
    Due to a bug that was fixed in C# 4, the following program prints true. (Try it in LINQPad) void Main() { new Derived(); } class Base { public Base(Func<string> valueMaker) { Console.WriteLine(valueMaker()); } } class Derived : Base { string CheckNull() { return "Am I null? " + (this == null); } public Derived() : base(() => CheckNull()) { } } In VS2008 in Release mode, in throws an InvalidProgramException. (In Debug mode, it works fine) In VS2010 Beta 2, it doesn't compile (I didn't try Beta 1); I learned that the hard way Is there any other way to make this == null in pure C#?

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  • Nested for loop error with !null checking an element that doesn't exist

    - by Programatt
    I am currently using nested for loops in a 2D array of size 4,2. When I run my program, I get index out of bounds Exception on the following line else if (state[i][j+1] != null && state[i][j].getFlash() <= state[i][j].getCycleLength() && state[i][j+1].getCycleLength() == state[i][j].getCycleLength()){ } It says the index out of bounds is 2. I would understand the error if I wasn't checking to see if [i][j+1] wasn't null, but I don't understand the exception with the check? I tried moving around the !null check but the program still fails on this line. Any help would be greatly appreciated. Stack trace: Exception in thread "Timer-0" java.lang.ArrayIndexOutOfBoundsException: 2 at NatComp.data$1.run(data.java:67) at java.util.TimerThread.mainLoop(Timer.java:512) at java.util.TimerThread.run(Timer.java:462)

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  • C# Events and Lambdas, alternative to null check?

    - by Eugarps
    Does anybody see any drawbacks? It should be noted that you can't remove anonymous methods from an event delegate list, I'm aware of that (actually that was the conceptual motivation for this). The goal here is an alternative to: if (onFoo != null) onFoo.Invoke(this, null); And the code: public delegate void FooDelegate(object sender, EventArgs e); public class EventTest { public EventTest() { onFoo += (p,q) => { }; } public FireFoo() { onFoo.Invoke(this, null); } public event FooDelegate onFoo; }

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  • JSP doPost getAtribute null value

    - by newbie123
    I want to pass value to servlet but I keep get null value. <jsp:useBean id="Helper" class="model.Registration" scope="request"/> <form action="/Project/Registration" method="post" enctype="multipart/form-data"> <input type="text" size="20" name="name" value="<%=Helper.getName()%>"> <input type="submit"> </form> protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { Registrationh2 = (Registration) request.getAttribute("Helper"); if(h2!=null){ System. out.println(h2.getName()); } else System. out.println("NULL"); } Is there anything wrong with my code?

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  • routing paramenter returns null when only supplying first paramenter in MVC

    - by Ray ForRespect
    My issue is that I customer Map Route in MVC which takes three parameters. When I supply all three or just two, the parameters are passed from the URL to my controller. However, when I only supply the first parameter, it is not passed and returns null. Not sure what causes this behavior. Route: routes.MapRoute( name: "Details", // Route name url: "{controller}/{action}/{param1}/{param2}/{param3}", // URL with parameters defaults: new { controller = "Details", action = "Index", param1 = UrlParameter.Optional, param2 = UrlParameter.Optional, param3 = UrlParameter.Optional } // Parameter defaults ); Controller: public ActionResult Map(string param1, string param2, string param3) { StoreMap makeMap = new StoreMap(); var storemap = makeMap.makeStoreMap(param1, param2, param3); var model = storemap; return View(model); } string param1 returns null when I navigate to: /StoreMap/Map/PARAM1NAME but it doesn't return null when I navigate to: /StoreMap/Map/PARAM1NAME/PARAM2NAME

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  • Cannot output json from MySQL - getting null value

    - by sky
    I'm using following code but cannot return data from MySQL. This is the output: <script type="text/javascript"> var somethings= [null,null,null]; </script> It does have three post, but I couldn't get the title(message) output. EDIT: this is the code I'm using: <?php $session = mysql_connect('localhost','name','pass'); mysql_select_db('dbname', $session); $result= mysql_query('SELECT * FROM posts', $session); $somethings= array(); while ($row= mysql_fetch_assoc($result)) { $somethings[]= $row['something']; } ?> <script type="text/javascript"> var somethings= <?php echo json_encode($somethings); ?>; </script>

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  • MVVM Binding To Property == Null

    - by LnDCobra
    I want to show some elements when a property is not null. What is the best way of achieving this? The following is my ViewModel: class ViewModel : ViewModelBase { public Trade Trade { get { return _trade; } set { SetField(ref _trade, value, () => Trade); } } private Trade _trade; } ViewModelBase inherits INotifyPropertyChanged and contains SetField() The Following is the Trade class: public class Trade : INotifyPropertyChaged { public virtual Company Company { get { return _company; } set { SetField(ref _company, value, () => Company); } } private Company _company; ...... } This is part of my View.xaml <GroupBox Visibility="{Binding Path=Trade.Company, Converter={StaticResource boolToVisConverter}}" /> I would like this groupbox to show only if Trade.Company is not null (so when a user selects a company). Would I need to create a custom converter to check for null and return the correct visibility or is there one in .NET?

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  • custom ListView --Null pointer exception

    - by raghs
    this code throws a Null pointer exception. It was thrown by getChildAt(i). The getCount() returns the number of items in listView. But getChildAt(i) returns only if item is present in current list view. For example in a scrollable list view assume that there are 20 items. The getCount() returns 20. But getChildAt(20) returns null. Because it doesnot fit in listview. How to solve this problem?? int i,j=object.getCount(); View v=getListView(); CheckBox chk=null; for(i=0;i<j;i++) { chk=((CheckBox)((ViewGroup) v).getChildAt(i).findViewById(R.id.checkBox1)); if(chk.isChecked()) { //download the contents to specific folder in sd card } }

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  • null pointer exception on list.add

    - by Eric
    I've been working on this one error for a few hours so I thought I'd pick the brains of some pros. I am getting a null pointer exception at the modelData.add(i, es) method. I know from debugging that es isn't null. I'm really confused, thanks. public class EventTableModel extends AbstractTableModel { //private int rowCount = 0; protected List<EventSeat> modelData; private static final int COLUMN_COUNT = 3; private Event e; Event j = GUIpos.m; int i = 1; public EventTableModel(Event e) { this.e = e; try { System.out.println(modelData); for (EventSeat es : e.getEventSeats()) { modelData.add(i, es); i++; } } catch (DataException ex) { Logger.getLogger(EventTableModel.class.getName()).log(Level.SEVERE, null, ex); } }

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  • Java - Does null variable require space in memory

    - by Yatendra Goel
    class CheckStore { private String displayText; private boolean state; private String meaningfulText; private URL url; public CheckStore(String text, boolean state) { this.displayText = text; this.state = state; } : : } As I am initializing only two variables (displayText and state) in the constructor, Will the rest two variables (meaningfulText and url which will have the value null) will require space in memory to store null value. Q1. I think they will require space. If they will, then how much memory does a null value takes in the memory (like int takes 4 bytes). Q2. How much space a string takes in memory. I guess it will depend on the length of the string. So how much space a string takes of how much length?

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  • if specific row = null, execute query

    - by fusion
    how do i check if the value of a column is null, and only then execute the query? for example: col1 col2 col3 01 abc i run a query which first checks if the record exists or not; if it exists, it should execute the update query and if it doesn't exist, it executes the insert query. how do i check if col3 is null and if it is null, it should execute the update query. . $sql = "SELECT uid FROM `users` WHERE uid = '" . $user_id . "'"; $result = mysql_query($sql,$conn) or die('Error:' .mysql_error()); $totalrows = mysql_num_rows($result); if($totalrows < 1) { insertUser($user_id,$sk, $conn); } else { updateSessionKey($user_id,$sk,$conn); }

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  • SQL Select between two fields depending on the value of one field

    - by Filip
    Hi. I am using a PostgreSQL database, and in a table representing some measurements I've two columns: measurement, and interpolated. In the first I've the observation (measurement), and b is the interpolated value depending on nearby values. Every record with an original value has also an interpolated value. However, there are a lot of records without "original" observations (NULL), hence the values are interpolated and stored in the second column. So basically there are just two cases in the database: Value Value NULL Value Of course, it is preferable to use the value from the first column if available, hence I need to build a query to select the data from the first column, and if not available (NULL), then the database returns the value from the second column for the record in question. I have no idea how to build the SQL query. Please help. Thanks.

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  • GWT : NULL Session

    - by jidma
    I'm using spring4gwt in my project. I have the following login service implementation: @Service("loginService") public class LoginServiceImpl extends RemoteServiceServlet implements LoginService { @Override @Transactional(propagation = Propagation.REQUIRED, rollbackFor = Exception.class) public UserBean checkUser(String userName, String password) throws Exception { HttpSession httpSession = getThreadLocalRequest().getSession(); } } When i call the loginService.checkUser("test","test") (In hosted mode), I get a null pointer exception, as getThreadLocalRequest() returns NULL instead of the actual session. I didn't try in web mode yet. Why would I get a null session ? Does it have something to do with spring4gwt ? Thank you

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  • Activiti Engine: Task Event - User is null

    - by sockeqwe
    I have a problem, which should be simple to solve, but i can't find the method to call to solve this problem: My problem is, that every Task Event (org.activiti.engine.task.Event) returnes null by calling Event.getUserId(); If I take a look into the database I see that the database table ACT_HI_COMMENT has null as value for the column USER_ID_ for every row. I generate these TaskEvents programmatically by calling (for example) processEngine.getTaskService().addComment(task.getId(), null, commentMessage); processEngine.getTaskService().addUserIdentityLink(task.getId(), user.getId(), IDENTITY_LINK_OBSERVER); I guess there is a simple method that I must call to solve this problem, something like processEngine.setCurrentUser(authenticatedUser.getId()); Any suggestions?

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  • Handling null values with PowerShell dates

    - by Tim Ferrill
    I'm working on a module to pull data from Oracle into a PowerShell data table, so I can automate some analysis and perform various actions based on the results. Everything seems to be working, and I'm casting columns into specific types based on the column type in Oracle. The problem I'm having has to do with null dates. I can't seem to find a good way to capture that a date column in Oracle has a null value. Is there any way to cast a [datetime] as null or empty?

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