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  • Hang during databinding of large amount of data to WPF DataGrid

    - by nihi_l_ist
    Im using WPFToolkit datagrid control and do the binding in such way: <WpfToolkit:DataGrid x:Name="dgGeneral" SelectionMode="Single" SelectionUnit="FullRow" AutoGenerateColumns="False" CanUserAddRows="False" CanUserDeleteRows="False" Grid.Row="1" ItemsSource="{Binding Path=Conversations}" > public List<CONVERSATION> Conversations { get { return conversations; } set { if (conversations != value) { conversations = value; NotifyPropertyChanged("Conversations"); } } } public event PropertyChangedEventHandler PropertyChanged; public void NotifyPropertyChanged(string propertyName) { if (PropertyChanged != null) { PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); } } public void GenerateData() { BackgroundWorker bw = new BackgroundWorker(); bw.WorkerSupportsCancellation = bw.WorkerReportsProgress = true; List<CONVERSATION> list = new List<CONVERSATION>(); bw.DoWork += delegate { list = RefreshGeneralData(); }; bw.RunWorkerCompleted += delegate { try { Conversations = list; } catch (Exception ex) { CustomException.ExceptionLogCustomMessage(ex); } }; bw.RunWorkerAsync(); } And than in the main window i call GenerateData() after setting DataCotext of the window to instance of the class, containing GenerateData(). RefreshGeneralData() returns some list of data i want and it returns it fast. Overall there are near 2000 records and 6 columns(im not posting the code i used during grid's initialization, because i dont think it can be the reason) and the grid hangs for almost 10 secs!

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  • Testing When Correctness is Poorly Defined?

    - by dsimcha
    I generally try to use unit tests for any code that has easily defined correct behavior given some reasonably small, well-defined set of inputs. This works quite well for catching bugs, and I do it all the time in my personal library of generic functions. However, a lot of the code I write is data mining code that basically looks for significant patterns in large datasets. Correct behavior in this case is often not well defined and depends on a lot of different inputs in ways that are not easy for a human to predict (i.e. the math can't reasonably be done by hand, which is why I'm using a computer to solve the problem in the first place). These inputs can be very complex, to the point where coming up with a reasonable test case is near impossible. Identifying the edge cases that are worth testing is extremely difficult. Sometimes the algorithm isn't even deterministic. Usually, I do the best I can by using asserts for sanity checks and creating a small toy test case with a known pattern and informally seeing if the answer at least "looks reasonable", without it necessarily being objectively correct. Is there any better way to test these kinds of cases?

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  • SQL query to calculate running group counts on time-phased data

    - by spong
    I have some data, like this: BUG DATE STATUS ---- ---------------------- -------- 9012 18/03/2008 9:08:44 AM OPEN 9012 18/03/2008 9:10:03 AM OPEN 9012 28/03/2008 4:55:03 PM RESOLVED 9012 28/03/2008 5:25:00 PM CLOSED 9013 18/03/2008 9:12:59 AM OPEN 9013 18/03/2008 9:15:06 AM RESOLVED 9013 18/03/2008 9:16:44 AM CLOSED 9014 18/03/2008 9:17:54 AM OPEN 9014 18/03/2008 9:18:31 AM RESOLVED 9014 18/03/2008 9:19:30 AM CLOSED 9015 18/03/2008 9:22:40 AM OPEN 9015 18/03/2008 9:23:03 AM RESOLVED 9015 19/03/2008 12:27:08 PM CLOSED 9016 18/03/2008 9:24:20 AM OPEN 9016 18/03/2008 9:24:35 AM RESOLVED 9016 19/03/2008 12:28:14 PM CLOSED 9017 18/03/2008 9:25:47 AM OPEN 9017 18/03/2008 9:26:02 AM RESOLVED 9017 19/03/2008 12:30:30 PM CLOSED Which I would like to transform into something like this: DATE OPEN RESOLVED CLOSED ---------------------- -------- -------- -------- 18/03/2008 9:08:44 AM 1 0 0 18/03/2008 9:12:59 AM 2 0 0 18/03/2008 9:15:06 AM 1 1 0 18/03/2008 9:16:44 AM 1 0 1 18/03/2008 9:17:54 AM 2 0 1 18/03/2008 9:18:31 AM 1 1 0 18/03/2008 9:19:30 AM 1 0 2 18/03/2008 9:22:40 AM 2 0 2 18/03/2008 9:23:03 AM 1 1 2 18/03/2008 9:24:20 AM 2 1 2 18/03/2008 9:24:35 AM 1 2 2 18/03/2008 9:25:47 AM 2 2 2 18/03/2008 9:26:02 AM 1 3 2 19/03/2008 12:27:08 PM 1 2 3 19/03/2008 12:28:14 PM 1 1 4 19/03/2008 12:30:30 PM 1 0 5 28/03/2008 4:55:03 PM 0 1 5 28/03/2008 5:25:00 PM 0 0 6 i.e. keeping running counts of bugs with each status. This is easy enough to code up using cursors, but I'm wondering if any of you SQL gurus out there can help with a query to achieve this? Ideally for mysql, but I'm curious to see anything that will work.

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  • return Queryable<T> or List<T> in a Repository<T>

    - by Danny Chen
    Currently I'm building an windows application using sqlite. In the data base there is a table say User, and in my code there is a Repository<User> and a UserManager. I think it's a very common design. In the repository there is a List method: //Repository<User> class public List<User> List(where, orderby, topN parameters and etc) { //query and return } This brings a problem, if I want to do something complex in UserManager.cs: //UserManager.cs public List<User> ListUsersWithBankAccounts() { var userRep = new UserRepository(); var bankRep = new BankAccountRepository(); var result = //do something complex, say "I want the users live in NY //and have at least two bank accounts in the system } You can see, returning List<User> brings performance issue, becuase the query is executed earlier than expected. Now I need to change it to something like a IQueryable<T>: //Repository<User> class public TableQuery<User> List(where, orderby, topN parameters and etc) { //query and return } TableQuery<T> is part of the sqlite driver, which is almost equals to IQueryable<T> in EF, which provides a query and won't execute it immediately. But now the problem is: in UserManager.cs, it doesn't know what is a TableQuery<T>, I need to add new reference and import namespaces like using SQLite.Query in the business layer project. It really brings bad code feeling. Why should my business layer know the details of the database? why should the business layer know what's SQLite? What's the correct design then?

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  • transfering a container of data to different classes

    - by user340699
    I am passing a vector of bids from Trader class to Simulator class.which class then passes it on to the auctioneer class.something seems messed up, can anyone spot it please. Below is part of the code: Error: 199 expected primary-expression before '&' token //Class of Origin of the vector. class Trader { private: int nextBidId; public: Trader(); ~Trader(){}; Bid getNextBid(); Bid getNextBid(int trdId, int qty, int price, char type); void loadRange( vector <Bid> & bids ) {} ; void loadRange(BidList &, int trdId, int qty, int price, char type, int size); }; //To be received by the Simulator class Simulator { vector <Bid> list; Trader trader; Auctioneer auctioneer; public: void run(); }; // Passing the vector into a function in simulator Simulator::accept_bids(bid_vector::const_iterator begin, bid_vector::const_iterator end){ vector<Bid>::iterator itr; } //Its journey should end with the Auctioneer. who displays the data class Auctioneer { public: vector <Bid>v2;// created a new vector to hold the objects void accept_bids(vector<Bid> & bids); void displayBids(){return bids} };

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  • Dropdown list bound to object data source - how to update on a button click

    - by Jen
    This is probably something really stupidly simple.. I have a drop down list bound to an object data source. I have set AppendDataBoundItems to true so that I can have an initial select. <asp:DropDownList ID="Accommodations1" runat="server" AutoPostBack="true" DataTextField="AccommodationTypeDescription" DataValueField="Id" OnDataBound="Accommodations1_DataBound" onSelectedIndexChanged="Accommodations1_SelectedIndexChanged" Width="200px" DataSourceID="AccommodationDs" AppendDataBoundItems="true"> <asp:ListItem Text="Select" Value=""></asp:ListItem> </asp:DropDownList> <asp:ObjectDataSource ID="AccommodationDs" runat="server" OldValuesParameterFormatString="original_{0}" SelectMethod="ListByPropertyId" TypeName="PropertyAccommodationController"> <SelectParameters> <asp:Parameter Name="PropertyId" Type="Int32" /> </SelectParameters> </asp:ObjectDataSource> I have a button which adds an accommodaton - so after that happens I need the dropdown list to update to include the new accommodation. So I've tried calling databind on the dropdownlist, and databind on the datasource - and nothing is making this dropdown list update. eg. PropertyAccommodations1.DataBind(); Could someone please let me know what I'm doing wrong. Originally I thought it was due to an update panel issue.. but I've removed the update panel and it still doesn't work (and checked the master page doesn't include an update panel). Thanks!!

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  • Append data to same text file

    - by Manu
    SimpleDateFormat formatter = new SimpleDateFormat("ddMMyyyy_HHmmSS"); String strCurrDate = formatter.format(new java.util.Date()); String strfileNm = "Customer_" + strCurrDate + ".txt"; String strFileGenLoc = strFileLocation + "/" + strfileNm; String Query1="select '0'||to_char(sysdate,'YYYYMMDD')||'123456789' class_code from dual"; String Query2="select '0'||to_char(sysdate,'YYYYMMDD')||'123456789' class_code from dual"; try { Statement stmt = null; ResultSet rs = null; Statement stmt1 = null; ResultSet rs1 = null; stmt = conn.createStatement(); stmt1 = conn.createStatement(); rs = stmt.executeQuery(Query1); rs1 = stmt1.executeQuery(Query2); File f = new File(strFileGenLoc); OutputStream os = (OutputStream)new FileOutputStream(f,true); String encoding = "UTF8"; OutputStreamWriter osw = new OutputStreamWriter(os, encoding); BufferedWriter bw = new BufferedWriter(osw); while (rs.next() ) { bw.write(rs.getString(1)==null? "":rs.getString(1)); bw.write(" "); } bw.flush(); bw.close(); } catch (Exception e) { System.out.println( "Exception occured while getting resultset by the query"); e.printStackTrace(); } finally { try { if (conn != null) { System.out.println("Closing the connection" + conn); conn.close(); } } catch (SQLException e) { System.out.println( "Exception occured while closing the connection"); e.printStackTrace(); } } return objArrayListValue; } The above code is working fine. it writes the content of "rs" resultset data in text file Now what i want is ,i need to append the the content in "rs2" resultset to the "same text file"(ie . i need to append "rs2" content with "rs" content in the same text file)..

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  • Loading data from file to Vector structure

    - by owca
    I'm trying to parse through fixed-width formatted file extracting x,y values of points from it, and then storing them in int[] array inside a Vector. Text file looks as follows : 0006 0015 0125 0047 0250 0131 That's the code : Vector<int[]> vc = new Vector<int[]>(); try { BufferedReader file = new BufferedReader(new FileReader("myfile.txt")); String s; int[] vec = new int[2]; while ((s = file.readLine()) != null) { vec[0] = Integer.parseInt(s.substring(0, 4).trim()); vec[1] = Integer.parseInt(s.substring(5, 8).trim()); vc.add(vec); } file.close(); } catch (IOException e) { } for(int i=0; i<vc.size(); i++){ for(int j=0; j<2; j++){ System.out.println(vc.elementAt(i)[j]); } } But the output shows only last line. 250 131 250 131 250 131 Should I somehow use Vector.nextElement() here to get all my data ?

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  • Beginner PHP: I can't insert data into MYSQL database

    - by Victor
    I'm learning PHP right now and I'm trying to insert data into a MySQL database called "pumpl2" The table is set up like this. create table product ( productid int unsigned not null auto_increment primary key, price int(9) not null, value int(9) not null, description text ); I have a form and want to insert the fields from the form in the database. Here is what the php file looks like. <?php // create short variable names $price = $_POST['price']; $value = $_POST['value']; $description = $_POST['description']; if (!$price || !$value || !$description) { echo "You have not entered all the required details.<br />" ."Please go back and try again."; exit; } @ $db = new mysqli('localhost', 'pumpl', '********', 'pumpl2'); if (mysqli_connect_errno()) { echo "Error: Could not connect to database. Please try again later."; exit; } $query = "insert into pumpl2 values ('".$price."', '".$value."', '".$description."')"; $result = $db->query($query); if ($result) { echo $db->affected_rows." product inserted into database."; } else { echo "An error has occurred. The item was not added."; } $db->close(); ?> When I submit the form, I get an error message "An error has occurred. The item was not added." Does anyone know what the problem is? Thank you!

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  • My treeview Data is Not changing.

    - by Vibin Jith
    Hai , I am trying to display the user permission in a treeview.For each user permissions are stored in the database as xml file. In the page, a Combo box used to list the users and a treeView used to bind the Permission xml. When the user get selected in the combo box , i took the xml from the database and connect with xmlDatasource and bind with the treeView. What happening is , First time the TreeView fill with the xml nodes and another time it will not work. For the first selection it's ok. Anothers selections are not effected by the treeview. The code is debugging. No problem. Can you just tell ,why the treeview datasource is not updating. I used this code .. Dim permissionRoot = From permissionNode In MyUser.UserPermissionXml.Root.Elements("menuNode") XmlTreeViewSource.Data = permissionRoot(0).ToString trvPermission.DataSource = XmlTreeViewSource trvPermission.DataBind() SetPermission(trvPermission.Nodes(0)) The markups <asp:TreeView ID="trvPermission" runat="server" ExpandDepth="2" ShowCheckBoxes="All" ShowLines="True" ForeColor="#005782" > <DataBindings> <asp:TreeNodeBinding DataMember="menuNode" TextField="title" ValueField="value" /> </DataBindings> </asp:TreeView>

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  • MVC design for archived data view

    - by Hemant Tank
    Implementation of a standard archive process in ASP.Net MVC. Backend SQL Server 2005 We've an existing web app built in MVC. We've an Entity "Claim" and it has some child entities like ClaimDetails, Files, etc... A pretty standard setup in DB. Each entity has its own table and are linked via FK. Now, we need to have an "Archive" feature in web app which will allow admin to archive a Claim and its child entities. An archived Claim shud become readonly when visited again. Here're some points on which I need your valued opinion - To keep it simple and scalable (for a few million records) for now we plan to simply add a bit field "Archived" to the Claim table in db. And change the behavior accordingly in the web app. We've a 'Manage claim' page which renders a bunch of diff views for Claim and its child entities. Now, for a readonly view we can either use the same views or have a separate set of views. What do you suggest? At controller level, we can identify archived claim and select which view to render. At model level, though it'd be great to be able to use the same model used for Manage Claim - but it might not get us the "text" of some lookup fields. For example, Claim.BrandId is rendered as a dropdown in Manage claim (requires only BrandId) but for readonly view we need 'BrandText'. Any existing ref or architecture level example would be great. Here's my prev SO post but its more about db level changes: Design a process to archive data (SQL Server 2005) Thank you.

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  • How to put a pre-existing sqlite file into <Application_Home>/Library/?

    - by Byron Cox
    My app uses Core Data. I have run the app in the simulator which has successfully created and populated the corresponding sqlite file. I now want to get this pre-existing sqlite file on to an actual device and be part of my app. I have located the simulator generated sqlite file at /Library/Application Support/iPhone Simulator/6.0/Applications/identifier/Documents/myapp.sqlite and dragged it into Xcode. This has added it to my application bundle but not in an appropriate directory (with the consequence that the sqlite file can be read but not written to). From reading about the file system I believe that the best place to put the sqlite file would be in a custom directory 'Database' under Application_Home/Library/. I don't seem to be able to do this within Xcode and despite searching I am unable to figure out how to do the following: (1) Create a sub-directory called 'Database' in Application_Home/Library/ ? (2) Transfer the sqlite file to my newly created 'Database' directory ? Many thanks to @Daij-Djan of his answer below. One other question: the path to the sqlite file will be used by the persistent store coordinator. Now depending on the size of the sqlite file it may take a while to copy or move. How can you ensure that the example code provided by @Daij-Djan has executed and finished before the persistent store coordinator tries to reference the sqlite file? Thanks for any help in advance.

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  • iPhone Development - CoreData runtime error

    - by Mustafa
    I'm facing a strange CoreData issue. Here's the log: 2010-04-07 15:59:36.913 MyProject[263:207] <MyEntity: 0x180370> (entity: MyEntity; id: 0x17e890 <x-coredata://0F55C533-41BD-4F09-9CCA-0CB304CAB065/MyEntity/p380> ; data: <fault>) 2010-04-07 15:59:36.918 MyProject[263:207] *** Terminating app due to uncaught exception 'NSObjectInaccessibleException', reason: 'The NSManagedObject with ID:0x17e890 <x-coredata://0F55C533-41BD-4F09-9CCA-0CB304CAB065/MyEntity/p380> has been invalidated.' I have a hierarchy of UITableViewControllers that use NSFetchedResultsController to populate the table, and when a particular row is selected, the detail view is shown. UITableView (MyMainEntity) UITableView (MyEntity) UITableView (MyEntity) detail view Both MyMainEntity UITableView and MyEntity UITableView use NSFetchedResultsController to show the records. Sometimes it crashes when i'm scrolling the tableView, and sometimes it crashes when i try to open the detail view. I can navigate to the MyEntity detail view multiple times before application crashes. What does this error mean? and how can i fix it!?

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  • Storing data in a MySQL database using MySQL & PHP

    - by comma
    I'm new to PHP and MySQL and I'm trying to store a users entered data from the following fields $skill, $experience, $years which a user can also add additional fields of $skill, $experience, $years if needed so in instead of 1 of each field there might be multiples of each field. I was wondering how can I store the fields in my MySQL database using PHP and MySQL? I have the following script but I know its wrong. can some one help me fix the script listed below? Here is the PHP and MySQL code. $skill = serialize($_POST['skill']); $experience = serialize($_POST['experience']); $years = serialize($_POST['years']); for (($s = 0; $s < count($skill); $s++) && ($x = 0; $x < count($experience); $x++) && ($g = 0; $g < count($years); $g++)){ $mysqli = mysqli_connect("localhost", "root", "", "sitename"); $query1 = "INSERT INTO learned_skills (skill, experience, years) VALUES ('" . $skill[$s] . "', '" . $experience[$x] . "', '" . $years[$g] . "')"; if (!mysqli_query($mysqli, $query1)) { print mysqli_error($mysqli); return; } } Here is my MySQL table. CREATE TABLE learned_skills ( id INT UNSIGNED NOT NULL AUTO_INCREMENT, skill TEXT NOT NULL, experience TEXT NOT NULL, years INT NOT NULL, PRIMARY KEY (id) ); CREATE TABLE u_skills ( id INT UNSIGNED NOT NULL AUTO_INCREMENT, skill_id INT UNSIGNED NOT NULL, users_id INT UNSIGNED NOT NULL, PRIMARY KEY (id) );

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  • How to retrieve data from a dialog box?

    - by Ralph
    Just trying to figure out an easy way to either pass or share some data between the main window and a dialog box. I've got a collection of variables in my main window that I want to pass to a dialog box so that they can be edited. They way I've done it now, is I pass in the list to the constructor of the dialog box: private void Button_Click(object sender, RoutedEventArgs e) { var window = new VariablesWindow(_templateVariables); window.Owner = this; window.ShowDialog(); if(window.DialogResult == true) _templateVariables = new List<Variable>(window.Variables); } And then in there, I guess I need to deep-copy the list, public partial class VariablesWindow : Window { public ObservableCollection<Variable> Variables { get; set; } public VariablesWindow(IEnumerable<Variable> vars) { Variables = new ObservableCollection<Variable>(vars); // ... So that when they're edited, it doesn't get reflected back in the main window until the user actually hits "Save". Is that the correct approach? If so, is there an easy way to deep-copy an ObservableCollection? Because as it stands now, I think my Variables are being modified because it's only doing a shallow-copy.

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  • Creating android app Database with big amount of data

    - by Thomas
    Hi all, The database of my application need to be filled with a lot of data, so during onCreate(), it's not only some create table sql instructions, there is a lot of inserts. The solution I chose is to store all this instructions in a sql file located in res/raw and which is loaded with Resources.openRawResource(id). It works well but I face to encoding issue, I have some accentuated caharacters in the sql file which appears bad in my application. This my code to do this : public String getFileContent(Resources resources, int rawId) throws IOException { InputStream is = resources.openRawResource(rawId); int size = is.available(); // Read the entire asset into a local byte buffer. byte[] buffer = new byte[size]; is.read(buffer); is.close(); // Convert the buffer into a string. return new String(buffer); } public void onCreate(SQLiteDatabase db) { try { // get file content String sqlCode = getFileContent(mCtx.getResources(), R.raw.db_create); // execute code for (String sqlStatements : sqlCode.split(";")) { db.execSQL(sqlStatements); } Log.v("Creating database done."); } catch (IOException e) { // Should never happen! Log.e("Error reading sql file " + e.getMessage(), e); throw new RuntimeException(e); } catch (SQLException e) { Log.e("Error executing sql code " + e.getMessage(), e); throw new RuntimeException(e); } The solution I found to avoid this is to load the sql instructions from a huge static final string instead of a file, and all accentutated characters appears well. But Isn't there a more elegant way to load sql instructions than a big static final String attribute with all sql instructions ? Thanks in advance Thomas

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  • Get type of the parameter from list of objects, templates, C++

    - by CrocodileDundee
    This question follows to my previous question Get type of the parameter, templates, C++ There is the following data structure: Object1.h template <class T> class Object1 { private: T a1; T a2; public: T getA1() {return a1;} typedef T type; }; Object2.h template <class T> class Object2: public Object1 <T> { private: T b1; T b2; public: T getB1() {return b1;} } List.h template <typename Item> struct TList { typedef std::vector <Item> Type; }; template <typename Item> class List { private: typename TList <Item>::Type items; }; Is there any way how to get type T of an object from the list of objects (i.e. Object is not a direct parameter of the function but a template parameter)? template <class Object> void process (List <Object> *objects) { typename Object::type a1 = objects[0].getA1(); // g++ error: 'Object1<double>*' is not a class, struct, or union type } But his construction works (i.e. Object represents a parameter of the function) template <class Object> void process (Object *o1) { typename Object::type a1 = o1.getA1(); // OK }

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  • Cached data accessed by reference?

    - by arthurdent510
    I am running into an odd problem, and this is the only thing I can think of. I'm storing a list in cache, and I am randomly losing items from my list as users use the site. I have a class that is called that either goes to cache and returns the list from there, or if the cache is over a certain time frame old, it goes to the database and refreshes the cache. So when I pull the data from cache, this is what it looks like.... results = (List<Software>)cache["software"]; And then I return results and do some processing, filter for security, and eventually it winds up on the screen. For each Software record, there can be multiple resources attached to it, and based on how the security goes they may see some, all, or none of the records. So in the security check it will remove some of those resources from the software record. So my question is.... when I return my results list, is it a reference directly to the cache object? So when I remove a resource from the software object, it is really removing from cache as well? If that is the case, is there any way to not return it as a reference? Thanks!

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  • A better way of getting a data table with various column types into string array

    - by Vlad
    This should be an easy one, looks like I got myself too confused. I get a table from a database, data ranges from varchar to int to Null values. Cheap and dirty way of converting this into a tab-delimited file that I already have is this (shrunken to preserve space, ugliness is kept on par with original): da.Fill(dt) ' da - DataAdapter ' ' dt - DataTable ' Dim lColumns As Long = dt.Columns.Count Dim arrColumns(dt.Columns.Count) As String Dim arrData(dt.Columns.Count) As Object Dim j As Long = 0 Dim arrData(dt.Columns.Count) As Object For i = 0 To dt.Rows.Count - 1 arrData = dt.Rows(i).ItemArray() For j = 0 To arrData.GetUpperBound(0) - 1 arrColumns(j) = arrData(j).ToString Next wrtOutput.WriteLine(String.Join(strFieldDelimiter, arrColumns)) Array.Clear(arrColumns, 0, arrColumns.GetLength(0)) Array.Clear(arrData, 0, arrData.GetLength(0)) Next Not only this is ugly and inefficient, it is also getting on my nerves. Besides, I want, if possible, to avoid the infamous double-loop through the table. I would really appreciate a clean and safe way of rewriting this piece. I like the approach that is used here - especially that is trying to solve the same problem that I have, but it crashes on me when I apply it to my case directly.

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  • Handling Denormalized Schema with Eclipselink

    - by iamrohitbanga
    Hello All I have a denormalized table containing employee information. The fields are employee id, name and department name. The primary key is a composite one consisting of all three fields. An employee can belong to multiple departments. I want to read/write the objects in the table using the Eclipselink Dynamic Persistence API (which is infact a wrapper on top of JPA descriptors etc.). Example Data: 1 e1 dep1 2 e1 dep2 3 e2 dep1 4 e2 dep3 5 e3 dep1 5 e3 dep2 5 e3 dep3 A normal ReadAllQuery (select query) on the table returns a DynamicEntity corresponding to each row in the table. However I want to club all entities based on the emp id and return all the departments he belongs to as a list. I can merge the entities after retrieving them but if I can use some Eclipselink feature out of the box then it would be better. One way to do the read is the following: I create two dynamic types corresponding to employee: Having id,name as the primary key Having id, department as the primary key, I create a OneToManyMapping from the first type to the second one. Then when I query the first type it does return the departments to which employee belongs as a list of DynamicEntity of the second type. This satisfies the read scenario. Is there a better way of doing this? Is this inherently supported by Eclipselink or JPA? I cannot get the same dynamic type configuration working for the write scenario. This is because when I write the changes using the writeObject method of UnitOfWork, it generates insert queries which enter the following entries in the table id name department 102 emp_102 102 st 102 dep_102 102 dep_102 102 dep_102 instead of: id name department 102 emp_102 st 102 emp_102 dep_102 102 emp_102 dep_102 102 emp_102 dep_102 Is there any way I can get write to work with this schema using eclipselink? I want to avoid doing the heavy lifting of merging the rows for such a denormalized schema or generating each row before doing a write. Is there no clean way of doing this using Eclipselink or JPA? Thanks in Advance.

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  • unclear use of @property in window app using core data

    - by Matt
    Looking through a Window based application ive used to experiment with as a way of getting my head around core data, ive noticed that the appdelegate has the following code myAppDelegate.h #import <UIKit/UIKit.h> #import <CoreData/CoreData.h> @interface iCaptureFreeAppDelegate : NSObject <UIApplicationDelegate> { NSManagedObjectModel *managedObjectModel; NSManagedObjectContext *managedObjectContext; NSPersistentStoreCoordinator *persistentStoreCoordinator; UIWindow *window; UITabBarController *tabBarController; } myAppDelegate.m #import "myAppDelegate.h" @interface iCaptureFreeAppDelegate (PrivateCoreDataStack) @property (nonatomic, retain, readonly) NSManagedObjectModel *managedObjectModel; @property (nonatomic, retain) NSManagedObjectContext *managedObjectContext; @property (nonatomic, retain, readonly) NSPersistentStoreCoordinator *persistentStoreCoordinator; @end @implementation iCaptureFreeAppDelegate @synthesize window, tabBarController; // code .... // - (NSManagedObjectContext *) managedObjectContext { } - (NSManagedObjectModel *)managedObjectModel { } - (NSPersistentStoreCoordinator *)persistentStoreCoordinator { } // etc..... i want to understand a few things about what this project is doing why the properties in the category declaration? (if i delete the privateCoreDataStack category everything still works...) why the properties appear to be linked with the methods in the implementation ... managedObjectContext {} etc why the members in the .h file have the same name as the properties and the methods why code completion lets me use dot '.' to access the members but then fails on compilation say it cant find a getter thanks !

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  • transferring binary files between systems

    - by tim
    Hi guys I'm trying to transfer my files between 2 UNIX clusters, the data is pure numeric (vectors of double) in binary form. Unfortunately one of the systems is IBM ppc997 and the other is AMD Opteron, It seems the format of binary numbers in these systems are different. I have tried 3 ways till now: 1- Changed my files to ASCII format (i.e. saved a number at each line in a text file), sent them to the destination and changed them again to binary on the target system (they both are UNIX, no end of line character difference??!) 2- Sent pure binaries to the destination 3- used uuencode sent them to the destination and decoded them Unfortunately any of these methods does not work (my code in the destination system generates garbage, while it works on the first system, I'm 100% sure the code itself is portable). I don't know what else I can do? Do you have any idea? I'm not a professional, please don't use computer scientists terminology! And: my codes are in C, so by binary I mean a one to one mapping between memory and hard disk. Thanks

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  • Implementation help... Subclass NSManagedObject?

    - by Canada Dev
    I'm working on an app where I have some products that I download in a list. The downloaded products are displayed in a table and each will is showing a detail view with more information. These same products can be saved as a favorite, and for this I am using Core Data. I'd like to be able to re-use a bunch of views for displaying the products, which means the stores object and the downloaded object would have to be the same kind. Now, how would I go about best implementing the objects? Can I make a class such as this: FavoriteProduct : NSManageObject // implementation and then subclass Product : FavoriteProduct // implementation ? The CD class just doesn't give me everything. What would be the best way to merge these two object classes so I have as little work ahead of me in terms of implementing the different views for each object? Basically, I just want to be able to call the same methods, etc. on the Product objects as I would on the ones that are FavoriteProduct objects, and re-use views for both kinds. There's only a bit of difference between the two (one is of course stored as a favorite and has some extra values such as notes, tags, while the Product one doesn't). Thanks in advance

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  • Ruby - Writing Hpricot data to a file

    - by John
    Hey everyone, I am currently doing some XML parsing and I've chosen to use Hpricot because of it's ease of use and syntax, however I am running into some problems. I need to write a piece of XML data that I have found out to another file. However, when I do this the format is not preserved. For example, if the content should look like this: <dict> <key>item1</key><value>12345</value> <key>item2</key><value>67890</value> <key>item3</key><value>23456</value> </dict> And assuming that there are many entries like this in the document. I am iterating through the 'dict' items by using hpricot_element = Hpricot(xml_document_body) f = File.new('some_new_file.xml') (hpricot_element/:dict).each { |dict| f.write( dict.to_original_html ) } After using the above code, I would expect that the output look like the following exactly like the XML shown above. However to my surprise, the output of the file looks more like this: <dict>\n", " <key>item1</key><value>12345</value>\n", " <key>item2</key><value>67890</value>\n", " <key>item3</key><value>23456</value\n", " </dict> I've tried splitting at the "\n" characters and writing to the file one line at a time, but that didn't seem to work either as it did not recognize the "\n" characters. Any help is greatly appreciated. It might be a very simple solution, but I am having troubling finding it. Thanks!

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  • How to load data on option box in php

    - by user225269
    I'm having trouble loading the mysql data on the html form option box using php. Here's my code: <?php $con = mysql_connect("localhost","myuname","mypassword"); if (!$con) { die('Could not connect: ' . mysql_error()); } mysql_select_db("school", $con); $idnum= mysql_real_escape_string($_POST['idnum']); $result = mysql_query("SELECT * FROM student WHERE IDNO='$idnum'"); ?> <?php while ( $row = mysql_fetch_array($result) ) { ?> <tr> <td width="30" height="35"><font size="2">*I D Number:</td> <td width="30"><input name="idnum" type="text" maxlength="5" value="<?php echo $row["IDNO"]; ?>" readonly="readonly"></td> </tr> My problem is loading it here: <td><font size="2">Gender</td> <td> <select name="gender" id="gender"> <font size="2"> <option value="<?php echo $line['IDNO']; ?> "><?php $line['GENDER'] ; ?></option> </select></td></td> The table looks like this: IDNO | GENDER 123 | M 321 | F What am I supposed to do?To load the exact gender corresponding to the IDNO?

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