Search Results

Search found 22900 results on 916 pages for 'pascal case'.

Page 460/916 | < Previous Page | 456 457 458 459 460 461 462 463 464 465 466 467  | Next Page >

  • Could not load type 'Default.DataMatch' in DataMatch.aspx file

    - by salvationishere
    I am developing a C# VS 2008 / SQL Server 2008 website, but now I am getting the above error when I build it. I included the Default.aspx, Default.aspx.cs, DataMatch.aspx, and DataMatch.aspx.cs files below. What do I need to do to fix this? Default.aspx: <%@ Page Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" Title="Untitled Page" %> ... DataMatch.aspx: <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="DataMatch.aspx.cs" Inherits="_Default.DataMatch" %> ... Default.aspx.cs: using System; using System.Collections; using System.Configuration; using System.Data; using System.Linq; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.HtmlControls; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Xml.Linq; using System.Collections.Generic; using System.IO; using System.Drawing; using System.ComponentModel; using System.Data.SqlClient; using ADONET_namespace; using System.Security.Principal; //using System.Windows; public partial class _Default : System.Web.UI.Page //namespace AddFileToSQL { //protected System.Web.UI.HtmlControls.HtmlInputFile uploadFile; //protected System.Web.UI.HtmlControls.HtmlInputButton btnOWrite; //protected System.Web.UI.HtmlControls.HtmlInputButton btnAppend; protected System.Web.UI.WebControls.Label Label1; protected static string inputfile = ""; public static string targettable; public static string selection; // Number of controls added to view state protected int default_NumberOfControls { get { if (ViewState["default_NumberOfControls"] != null) { return (int)ViewState["default_NumberOfControls"]; } else { return 0; } } set { ViewState["default_NumberOfControls"] = value; } } protected void uploadFile_onclick(object sender, EventArgs e) { } protected void Load_GridData() { //GridView1.DataSource = ADONET_methods.DisplaySchemaTables(); //GridView1.DataBind(); } protected void btnOWrite_Click(object sender, EventArgs e) { if (uploadFile.PostedFile.ContentLength > 0) { feedbackLabel.Text = "You do not have sufficient access to overwrite table records."; } else { feedbackLabel.Text = "This file does not contain any data."; } } protected void btnAppend_Click(object sender, EventArgs e) { string fullpath = Page.Request.PhysicalApplicationPath; string path = uploadFile.PostedFile.FileName; if (File.Exists(path)) { // Create a file to write to. try { StreamReader sr = new StreamReader(path); string s = ""; while (sr.Peek() > 0) s = sr.ReadLine(); sr.Close(); } catch (IOException exc) { Console.WriteLine(exc.Message + "Cannot open file."); return; } } if (uploadFile.PostedFile.ContentLength > 0) { inputfile = System.IO.File.ReadAllText(path); Session["Message"] = inputfile; Response.Redirect("DataMatch.aspx"); } else { feedbackLabel.Text = "This file does not contain any data."; } } protected void Page_Load(object sender, EventArgs e) { if (Request.IsAuthenticated) { WelcomeBackMessage.Text = "Welcome back, " + User.Identity.Name + "!"; // Reference the CustomPrincipal / CustomIdentity CustomIdentity ident = User.Identity as CustomIdentity; if (ident != null) WelcomeBackMessage.Text += string.Format(" You are the {0} of {1}.", ident.Title, ident.CompanyName); AuthenticatedMessagePanel.Visible = true; AnonymousMessagePanel.Visible = false; if (!Page.IsPostBack) { Load_GridData(); } } else { AuthenticatedMessagePanel.Visible = false; AnonymousMessagePanel.Visible = true; } } protected void GridView1_SelectedIndexChanged(object sender, EventArgs e) { GridViewRow row = GridView1.SelectedRow; targettable = row.Cells[2].Text; } } DataMatch.aspx.cs: using System; using System.Collections; using System.Collections.Generic; using System.Data; using System.Data.SqlClient; using System.Diagnostics; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using ADONET_namespace; //using MatrixApp; //namespace AddFileToSQL //{ public partial class DataMatch : AddFileToSQL._Default { protected System.Web.UI.WebControls.PlaceHolder phTextBoxes; protected System.Web.UI.WebControls.PlaceHolder phDropDownLists; protected System.Web.UI.WebControls.Button btnAnotherRequest; protected System.Web.UI.WebControls.Panel pnlCreateData; protected System.Web.UI.WebControls.Literal lTextData; protected System.Web.UI.WebControls.Panel pnlDisplayData; protected static string inputfile2; static string[] headers = null; static string[] data = null; static string[] data2 = null; static DataTable myInputFile = new DataTable("MyInputFile"); static string[] myUserSelections; static bool restart = false; private DropDownList[] newcol; int @temp = 0; string @tempS = ""; string @tempT = ""; // a Property that manages a counter stored in ViewState protected int NumberOfControls { get { return (int)ViewState["NumControls"]; } set { ViewState["NumControls"] = value; } } private Hashtable ddl_ht { get { return (Hashtable)ViewState["ddl_ht"]; } set { ViewState["ddl_ht"] = value; } } // Page Load private void Page_Load(object sender, System.EventArgs e) { if (!Page.IsPostBack) { ddl_ht = new Hashtable(); this.NumberOfControls = 0; } } // This data comes from input file private void PopulateFileInputTable() { myInputFile.Columns.Clear(); string strInput, newrow; string[] oneRow; DataColumn myDataColumn; DataRow myDataRow; int result, numRows; //Read the input file strInput = Session["Message"].ToString(); data = strInput.Split('\r'); //Headers headers = data[0].Split('|'); //Data for (int i = 0; i < data.Length; i++) { newrow = data[i].TrimStart('\n'); data[i] = newrow; } result = String.Compare(data[data.Length - 1], ""); numRows = data.Length; if (result == 0) { numRows = numRows - 1; } data2 = new string[numRows]; for (int a = 0, b = 0; a < numRows; a++, b++) { data2[b] = data[a]; } // Create columns for (int col = 0; col < headers.Length; col++) { @temp = (col + 1); @tempS = @temp.ToString(); @tempT = "@col"+ @temp.ToString(); myDataColumn = new DataColumn(); myDataColumn.DataType = Type.GetType("System.String"); myDataColumn.ColumnName = headers[col]; myInputFile.Columns.Add(myDataColumn); ddl_ht.Add(@tempT, headers[col]); } // Create new DataRow objects and add to DataTable. for (int r = 0; r < numRows - 1; r++) { oneRow = data2[r + 1].Split('|'); myDataRow = myInputFile.NewRow(); for (int c = 0; c < headers.Length; c++) { myDataRow[c] = oneRow[c]; } myInputFile.Rows.Add(myDataRow); } NumberOfControls = headers.Length; myUserSelections = new string[NumberOfControls]; } //Create display panel private void CreateDisplayPanel() { btnSubmit.Style.Add("top", "auto"); btnSubmit.Style.Add("left", "auto"); btnSubmit.Style.Add("position", "absolute"); btnSubmit.Style.Add("top", "200px"); btnSubmit.Style.Add("left", "400px"); newcol = CreateDropDownLists(); for (int counter = 0; counter < NumberOfControls; counter++) { pnlDisplayData.Controls.Add(newcol[counter]); pnlDisplayData.Controls.Add(new LiteralControl("<br><br><br>")); pnlDisplayData.Visible = true; pnlDisplayData.FindControl(newcol[counter].ID); } } //Recreate display panel private void RecreateDisplayPanel() { btnSubmit.Style.Add("top", "auto"); btnSubmit.Style.Add("left", "auto"); btnSubmit.Style.Add("position", "absolute"); btnSubmit.Style.Add("top", "200px"); btnSubmit.Style.Add("left", "400px"); newcol = RecreateDropDownLists(); for (int counter = 0; counter < NumberOfControls; counter++) { pnlDisplayData.Controls.Add(newcol[counter]); pnlDisplayData.Controls.Add(new LiteralControl("<br><br><br>")); pnlDisplayData.Visible = true; pnlDisplayData.FindControl(newcol[counter].ID); } } // Add DropDownList Control to Placeholder private DropDownList[] CreateDropDownLists() { DropDownList[] dropDowns = new DropDownList[NumberOfControls]; for (int counter = 0; counter < NumberOfControls; counter++) { DropDownList ddl = new DropDownList(); SqlDataReader dr2 = ADONET_methods.DisplayTableColumns(targettable); ddl.ID = "DropDownListID" + counter.ToString(); int NumControls = targettable.Length; DataTable dt = new DataTable(); dt.Load(dr2); ddl.DataValueField = "COLUMN_NAME"; ddl.DataTextField = "COLUMN_NAME"; ddl.DataSource = dt; ddl.SelectedIndexChanged += new EventHandler(ddlList_SelectedIndexChanged); ddl.DataBind(); ddl.AutoPostBack = true; ddl.EnableViewState = true; //Preserves View State info on Postbacks dr2.Close(); ddl.Items.Add("IGNORE"); dropDowns[counter] = ddl; } return dropDowns; } protected void ddlList_SelectedIndexChanged(object sender, EventArgs e) { DropDownList ddl = (DropDownList)sender; string ID = ddl.ID; } // Add TextBoxes Control to Placeholder private DropDownList[] RecreateDropDownLists() { DropDownList[] dropDowns = new DropDownList[NumberOfControls]; for (int counter = 0; counter < NumberOfControls; counter++) { DropDownList ddl = new DropDownList(); SqlDataReader dr2 = ADONET_methods.DisplayTableColumns(targettable); ddl.ID = "DropDownListID" + counter.ToString(); int NumControls = targettable.Length; DataTable dt = new DataTable(); dt.Load(dr2); ddl.DataValueField = "COLUMN_NAME"; ddl.DataTextField = "COLUMN_NAME"; ddl.DataSource = dt; ddl.SelectedIndexChanged += new EventHandler(ddlList_SelectedIndexChanged); ddl.DataBind(); ddl.AutoPostBack = true; ddl.EnableViewState = false; //Preserves View State info on Postbacks dr2.Close(); ddl.Items.Add("IGNORE"); dropDowns[counter] = ddl; } return dropDowns; } private void CreateLabels() { for (int counter = 0; counter < NumberOfControls; counter++) { Label lbl = new Label(); lbl.ID = "Label" + counter.ToString(); lbl.Text = headers[counter]; lbl.Style["position"] = "absolute"; lbl.Style["top"] = 60 * counter + 10 + "px"; lbl.Style["left"] = 250 + "px"; pnlDisplayData.Controls.Add(lbl); pnlDisplayData.Controls.Add(new LiteralControl("<br><br><br>")); } } // Add TextBoxes Control to Placeholder private void RecreateLabels() { for (int counter = 0; counter < NumberOfControls; counter++) { Label lbl = new Label(); lbl.ID = "Label" + counter.ToString(); lbl.Text = headers[counter]; lbl.Style["position"] = "absolute"; lbl.Style["top"] = 60 * counter + 10 + "px"; lbl.Style["left"] = 250 + "px"; pnlDisplayData.Controls.Add(lbl); pnlDisplayData.Controls.Add(new LiteralControl("<br><br><br>")); } } // Create TextBoxes and DropDownList data here on postback. protected override void CreateChildControls() { // create the child controls if the server control does not contains child controls this.EnsureChildControls(); // Creates a new ControlCollection. this.CreateControlCollection(); // Here we are recreating controls to persist the ViewState on every post back if (Page.IsPostBack) { RecreateDisplayPanel(); RecreateLabels(); } // Create these conrols when asp.net page is created else { PopulateFileInputTable(); CreateDisplayPanel(); CreateLabels(); } // Prevent dropdownlists and labels from being created again. if (restart == false) { this.ChildControlsCreated = true; } else if (restart == true) { this.ChildControlsCreated = false; } } private void AppendRecords() { switch (targettable) { case "ContactType": for (int r = 0; r < myInputFile.Rows.Count; r++) { resultLabel.Text = ADONET_methods.AppendDataCT(myInputFile.Rows[r], ddl_ht); } break; case "Contact": for (int r = 0; r < myInputFile.Rows.Count; r++) { resultLabel.Text = ADONET_methods.AppendDataC(myInputFile.Rows[r], ddl_ht); } break; case "AddressType": for (int r = 0; r < myInputFile.Rows.Count; r++) { resultLabel.Text = ADONET_methods.AppendDataAT(myInputFile.Rows[r], ddl_ht); } break; default: resultLabel.Text = "You do not have access to modify this table. Please select a different target table and try again."; restart = true; break; //throw new ArgumentOutOfRangeException("targettable type", targettable); } } // Read all the data from TextBoxes and DropDownLists protected void btnSubmit_Click(object sender, System.EventArgs e) { //int cnt = FindOccurence("DropDownListID"); AppendRecords(); pnlDisplayData.Visible = false; btnSubmit.Visible = false; resultLabel.Attributes.Add("style", "align:center"); btnSubmit.Style.Add("top", "auto"); btnSubmit.Style.Add("left", "auto"); btnSubmit.Style.Add("position", "absolute"); int bSubmitPosition = NumberOfControls; btnSubmit.Style.Add("top", System.Convert.ToString(bSubmitPosition)+"px"); resultLabel.Visible = true; Instructions.Visible = false; if (restart == true) { CreateChildControls(); } } private int FindOccurence(string substr) { string reqstr = Request.Form.ToString(); return ((reqstr.Length - reqstr.Replace(substr, "").Length) / substr.Length); } #region Web Form Designer generated code override protected void OnInit(EventArgs e) { // // CODEGEN: This call is required by the ASP.NET Web Form Designer. // InitializeComponent(); base.OnInit(e); } /// <summary> /// Required method for Designer support - do not modify /// the contents of this method with the code editor. /// </summary> private void InitializeComponent() { } #endregion } //}

    Read the article

  • How can I Setup overloaded method invocations in Moq?

    - by arootbeer
    I'm trying to mock a mapping interface IMapper: public interface IMapper<TFoo, TBar> { TBar Map(TFoo foo); TFoo Map(TBar bar); } In my test, I'm setting the mock mapper up to expect an invocation of each (around an NHibernate update operation): //... _mapperMock.Setup(m => m.Map(fooMock.Object)).Returns(barMock.Object); _mapperMock.Setup(m => m.Map(barMock.Object)).Returns(fooMock.Object); //... However, when the second Map invocation is made, the mapper mock throws because it is only expecting a single invocation. Watching the mapper mock during setup at runtime, I can look see the Map(TFoo foo) overload get registered, and then see it get replaced when the Map(TBar bar) overload is set up. Is this a problem with the way Moq handles setup, or is there a different syntax I need to use in this case?

    Read the article

  • Merging dictionaries in C#

    - by orip
    What's the best way to merge 2 or more dictionaries (Dictionary<T1,T2>) in C#? (3.0 features like LINQ are fine). I'm thinking of a method signature along the lines of: public static Dictionary<TKey,TValue> Merge<TKey,TValue>(Dictionary<TKey,TValue>[] dictionaries); or public static Dictionary<TKey,TValue> Merge<TKey,TValue>(IEnumerable<Dictionary<TKey,TValue>> dictionaries); EDIT: Got a cool solution from JaredPar and Jon Skeet, but I was thinking of something that handles duplicate keys. In case of collision, it doesn't matter which value is saved to the dict as long as it's consistent.

    Read the article

  • Prevent ASP.net __doPostback() from jQuery submit() within UpdatePanel

    - by Ed Woodcock
    I'm trying to stop postback on form submit if my custom jQuery validation returns false. Is there any way to prevent the __doPostback() function finishing from within the submit() function? I'd assumed: $('#aspnetForm').submit(function () { return false; }); would do the trick, but apparently that's not the case: does anyone have a suggestion? The submit() function does block the postback (it won't postback if you pause at a breakpoint in firebug), but I can't seem to stop the event happening after the submit() function is complete! Cheers, Ed EDIT OK, I had a quick mess about and discovered that the fact that the button I'm using to cause the postback is tied to an updatepanel as an asyncpostbacktrigger seems to be the problem: If I remove it as a trigger (i.e. cause it to product a full postback), the is no problem preventing the postback with return false; Any ideas why the async postback would not be stoppable using return false?

    Read the article

  • Programmatically examine DLL contents

    - by Peter Hansen
    Is it possible programmatically to discover the exported names (globals, entry points, whatever) in a Windows DLL file without implementing a parser for the binary executable file format itself? I know there are tools to do this (though no open source ones I've found), but I'm curious whether there is a Windows API to accomplish the same thing or whether such tools operate merely by examining the binary file directly. I suspect there is an API for .NET libraries: if that's the case then is there a similar one for native DLLs? Edit: http://stackoverflow.com/questions/1128150 is basically an exact duplicate. The answer there is roughly "there is no API, but you can hack it using LoadLibraryEx() and navigating a few resulting data structures". Edit: I was able to use the accepted answer at http://stackoverflow.com/questions/1128150 to create a quick DLL dumper with Python and ctypes that works.

    Read the article

  • call python with system() in R to run a python script emulating the python console

    - by Yihui
    I want to pass a chunk of Python code to Python in R with something like system('python ...'), and I'm wondering if there is an easy way to emulate the python console in this case. For example, suppose the code is "print 'hello world'", how can I get the output like this in R? >>> print 'hello world' hello world This only shows the output: > system("python -c 'print \"hello world\"'") hello world Thanks! BTW, I asked in r-help but have not got a response yet (if I do, I'll post the answer here).

    Read the article

  • ASP.Net Authentication with MVC2--how to integrate with DB?

    - by alchemical
    I'm trying to understand the authentication section sample project that opens in a new MVC2 project in VS2010. It essentially lets you register, login, etc. I looked through the code that implements this briefly, it looked fairly complicated. (10 tables, 40 sprocs, 10 views, 4 models, 1 model, 1 controller, etc.) Is it best to utilize this provided framework for authentication? If so, how would I integrate this with my own database models (which has user and role tables, etc.). Also, if I use their framework, are there any performance issues at higher traffic volumes (like SO for example), do I need to become responsible for maintaining the authentication DB as well in this case?

    Read the article

  • Windows 7 64 / Visual Studio 2008 / OpenCV2.1 error: "The application was unable to start correctly

    - by James
    Hey all, I'm building OpenCV2.1 from top of branch in 64 bit mode, when I link the libraries against my code (that works in 32 bit mode on XP), I get the dialog: "The application was unable to start correctly (0xc0150002) Click OK to close the application" When I start the application. The event viewer is pointing at one of the OpenCV dll's & says it's a Side-by-Side error, but I'm definitely building OpenCV & my code as a 64 bit compile, and there are no errors during that process. I've tried fiddling with the /MTd options & it doesn't help. Some (almost) related questions have suggested installing the VS2008 redistributable package, but I'm building using vs2008 pro, that seems like madness? Is it still necessary to install the package in my case? Any help, including the cause of these side-by-side errors, would be appreciated. James

    Read the article

  • Inheritance Mapping Strategies with Entity Framework Code First CTP5 Part 1: Table per Hierarchy (TPH)

    - by mortezam
    A simple strategy for mapping classes to database tables might be “one table for every entity persistent class.” This approach sounds simple enough and, indeed, works well until we encounter inheritance. Inheritance is such a visible structural mismatch between the object-oriented and relational worlds because object-oriented systems model both “is a” and “has a” relationships. SQL-based models provide only "has a" relationships between entities; SQL database management systems don’t support type inheritance—and even when it’s available, it’s usually proprietary or incomplete. There are three different approaches to representing an inheritance hierarchy: Table per Hierarchy (TPH): Enable polymorphism by denormalizing the SQL schema, and utilize a type discriminator column that holds type information. Table per Type (TPT): Represent "is a" (inheritance) relationships as "has a" (foreign key) relationships. Table per Concrete class (TPC): Discard polymorphism and inheritance relationships completely from the SQL schema.I will explain each of these strategies in a series of posts and this one is dedicated to TPH. In this series we'll deeply dig into each of these strategies and will learn about "why" to choose them as well as "how" to implement them. Hopefully it will give you a better idea about which strategy to choose in a particular scenario. Inheritance Mapping with Entity Framework Code FirstAll of the inheritance mapping strategies that we discuss in this series will be implemented by EF Code First CTP5. The CTP5 build of the new EF Code First library has been released by ADO.NET team earlier this month. EF Code-First enables a pretty powerful code-centric development workflow for working with data. I’m a big fan of the EF Code First approach, and I’m pretty excited about a lot of productivity and power that it brings. When it comes to inheritance mapping, not only Code First fully supports all the strategies but also gives you ultimate flexibility to work with domain models that involves inheritance. The fluent API for inheritance mapping in CTP5 has been improved a lot and now it's more intuitive and concise in compare to CTP4. A Note For Those Who Follow Other Entity Framework ApproachesIf you are following EF's "Database First" or "Model First" approaches, I still recommend to read this series since although the implementation is Code First specific but the explanations around each of the strategies is perfectly applied to all approaches be it Code First or others. A Note For Those Who are New to Entity Framework and Code-FirstIf you choose to learn EF you've chosen well. If you choose to learn EF with Code First you've done even better. To get started, you can find a great walkthrough by Scott Guthrie here and another one by ADO.NET team here. In this post, I assume you already setup your machine to do Code First development and also that you are familiar with Code First fundamentals and basic concepts. You might also want to check out my other posts on EF Code First like Complex Types and Shared Primary Key Associations. A Top Down Development ScenarioThese posts take a top-down approach; it assumes that you’re starting with a domain model and trying to derive a new SQL schema. Therefore, we start with an existing domain model, implement it in C# and then let Code First create the database schema for us. However, the mapping strategies described are just as relevant if you’re working bottom up, starting with existing database tables. I’ll show some tricks along the way that help you dealing with nonperfect table layouts. Let’s start with the mapping of entity inheritance. -- The Domain ModelIn our domain model, we have a BillingDetail base class which is abstract (note the italic font on the UML class diagram below). We do allow various billing types and represent them as subclasses of BillingDetail class. As for now, we support CreditCard and BankAccount: Implement the Object Model with Code First As always, we start with the POCO classes. Note that in our DbContext, I only define one DbSet for the base class which is BillingDetail. Code First will find the other classes in the hierarchy based on Reachability Convention. public abstract class BillingDetail  {     public int BillingDetailId { get; set; }     public string Owner { get; set; }             public string Number { get; set; } } public class BankAccount : BillingDetail {     public string BankName { get; set; }     public string Swift { get; set; } } public class CreditCard : BillingDetail {     public int CardType { get; set; }                     public string ExpiryMonth { get; set; }     public string ExpiryYear { get; set; } } public class InheritanceMappingContext : DbContext {     public DbSet<BillingDetail> BillingDetails { get; set; } } This object model is all that is needed to enable inheritance with Code First. If you put this in your application you would be able to immediately start working with the database and do CRUD operations. Before going into details about how EF Code First maps this object model to the database, we need to learn about one of the core concepts of inheritance mapping: polymorphic and non-polymorphic queries. Polymorphic Queries LINQ to Entities and EntitySQL, as object-oriented query languages, both support polymorphic queries—that is, queries for instances of a class and all instances of its subclasses, respectively. For example, consider the following query: IQueryable<BillingDetail> linqQuery = from b in context.BillingDetails select b; List<BillingDetail> billingDetails = linqQuery.ToList(); Or the same query in EntitySQL: string eSqlQuery = @"SELECT VAlUE b FROM BillingDetails AS b"; ObjectQuery<BillingDetail> objectQuery = ((IObjectContextAdapter)context).ObjectContext                                                                          .CreateQuery<BillingDetail>(eSqlQuery); List<BillingDetail> billingDetails = objectQuery.ToList(); linqQuery and eSqlQuery are both polymorphic and return a list of objects of the type BillingDetail, which is an abstract class but the actual concrete objects in the list are of the subtypes of BillingDetail: CreditCard and BankAccount. Non-polymorphic QueriesAll LINQ to Entities and EntitySQL queries are polymorphic which return not only instances of the specific entity class to which it refers, but all subclasses of that class as well. On the other hand, Non-polymorphic queries are queries whose polymorphism is restricted and only returns instances of a particular subclass. In LINQ to Entities, this can be specified by using OfType<T>() Method. For example, the following query returns only instances of BankAccount: IQueryable<BankAccount> query = from b in context.BillingDetails.OfType<BankAccount>() select b; EntitySQL has OFTYPE operator that does the same thing: string eSqlQuery = @"SELECT VAlUE b FROM OFTYPE(BillingDetails, Model.BankAccount) AS b"; In fact, the above query with OFTYPE operator is a short form of the following query expression that uses TREAT and IS OF operators: string eSqlQuery = @"SELECT VAlUE TREAT(b as Model.BankAccount)                       FROM BillingDetails AS b                       WHERE b IS OF(Model.BankAccount)"; (Note that in the above query, Model.BankAccount is the fully qualified name for BankAccount class. You need to change "Model" with your own namespace name.) Table per Class Hierarchy (TPH)An entire class hierarchy can be mapped to a single table. This table includes columns for all properties of all classes in the hierarchy. The concrete subclass represented by a particular row is identified by the value of a type discriminator column. You don’t have to do anything special in Code First to enable TPH. It's the default inheritance mapping strategy: This mapping strategy is a winner in terms of both performance and simplicity. It’s the best-performing way to represent polymorphism—both polymorphic and nonpolymorphic queries perform well—and it’s even easy to implement by hand. Ad-hoc reporting is possible without complex joins or unions. Schema evolution is straightforward. Discriminator Column As you can see in the DB schema above, Code First has to add a special column to distinguish between persistent classes: the discriminator. This isn’t a property of the persistent class in our object model; it’s used internally by EF Code First. By default, the column name is "Discriminator", and its type is string. The values defaults to the persistent class names —in this case, “BankAccount” or “CreditCard”. EF Code First automatically sets and retrieves the discriminator values. TPH Requires Properties in SubClasses to be Nullable in the Database TPH has one major problem: Columns for properties declared by subclasses will be nullable in the database. For example, Code First created an (INT, NULL) column to map CardType property in CreditCard class. However, in a typical mapping scenario, Code First always creates an (INT, NOT NULL) column in the database for an int property in persistent class. But in this case, since BankAccount instance won’t have a CardType property, the CardType field must be NULL for that row so Code First creates an (INT, NULL) instead. If your subclasses each define several non-nullable properties, the loss of NOT NULL constraints may be a serious problem from the point of view of data integrity. TPH Violates the Third Normal FormAnother important issue is normalization. We’ve created functional dependencies between nonkey columns, violating the third normal form. Basically, the value of Discriminator column determines the corresponding values of the columns that belong to the subclasses (e.g. BankName) but Discriminator is not part of the primary key for the table. As always, denormalization for performance can be misleading, because it sacrifices long-term stability, maintainability, and the integrity of data for immediate gains that may be also achieved by proper optimization of the SQL execution plans (in other words, ask your DBA). Generated SQL QueryLet's take a look at the SQL statements that EF Code First sends to the database when we write queries in LINQ to Entities or EntitySQL. For example, the polymorphic query for BillingDetails that you saw, generates the following SQL statement: SELECT  [Extent1].[Discriminator] AS [Discriminator],  [Extent1].[BillingDetailId] AS [BillingDetailId],  [Extent1].[Owner] AS [Owner],  [Extent1].[Number] AS [Number],  [Extent1].[BankName] AS [BankName],  [Extent1].[Swift] AS [Swift],  [Extent1].[CardType] AS [CardType],  [Extent1].[ExpiryMonth] AS [ExpiryMonth],  [Extent1].[ExpiryYear] AS [ExpiryYear] FROM [dbo].[BillingDetails] AS [Extent1] WHERE [Extent1].[Discriminator] IN ('BankAccount','CreditCard') Or the non-polymorphic query for the BankAccount subclass generates this SQL statement: SELECT  [Extent1].[BillingDetailId] AS [BillingDetailId],  [Extent1].[Owner] AS [Owner],  [Extent1].[Number] AS [Number],  [Extent1].[BankName] AS [BankName],  [Extent1].[Swift] AS [Swift] FROM [dbo].[BillingDetails] AS [Extent1] WHERE [Extent1].[Discriminator] = 'BankAccount' Note how Code First adds a restriction on the discriminator column and also how it only selects those columns that belong to BankAccount entity. Change Discriminator Column Data Type and Values With Fluent API Sometimes, especially in legacy schemas, you need to override the conventions for the discriminator column so that Code First can work with the schema. The following fluent API code will change the discriminator column name to "BillingDetailType" and the values to "BA" and "CC" for BankAccount and CreditCard respectively: protected override void OnModelCreating(System.Data.Entity.ModelConfiguration.ModelBuilder modelBuilder) {     modelBuilder.Entity<BillingDetail>()                 .Map<BankAccount>(m => m.Requires("BillingDetailType").HasValue("BA"))                 .Map<CreditCard>(m => m.Requires("BillingDetailType").HasValue("CC")); } Also, changing the data type of discriminator column is interesting. In the above code, we passed strings to HasValue method but this method has been defined to accepts a type of object: public void HasValue(object value); Therefore, if for example we pass a value of type int to it then Code First not only use our desired values (i.e. 1 & 2) in the discriminator column but also changes the column type to be (INT, NOT NULL): modelBuilder.Entity<BillingDetail>()             .Map<BankAccount>(m => m.Requires("BillingDetailType").HasValue(1))             .Map<CreditCard>(m => m.Requires("BillingDetailType").HasValue(2)); SummaryIn this post we learned about Table per Hierarchy as the default mapping strategy in Code First. The disadvantages of the TPH strategy may be too serious for your design—after all, denormalized schemas can become a major burden in the long run. Your DBA may not like it at all. In the next post, we will learn about Table per Type (TPT) strategy that doesn’t expose you to this problem. References ADO.NET team blog Java Persistence with Hibernate book a { text-decoration: none; } a:visited { color: Blue; } .title { padding-bottom: 5px; font-family: Segoe UI; font-size: 11pt; font-weight: bold; padding-top: 15px; } .code, .typeName { font-family: consolas; } .typeName { color: #2b91af; } .padTop5 { padding-top: 5px; } .padTop10 { padding-top: 10px; } p.MsoNormal { margin-top: 0in; margin-right: 0in; margin-bottom: 10.0pt; margin-left: 0in; line-height: 115%; font-size: 11.0pt; font-family: "Calibri" , "sans-serif"; }

    Read the article

  • Implementing History Support using jQuery for AJAX websites built on asp.net AJAX

    - by anil.kasalanati
    Problem Statement: Most modern day website use AJAX for page navigation and gone are the days of complete HTTP redirection so it is imperative that we support back and forward buttons on the browser so that end users navigation is not broken. In this article we discuss about solutions which are already available and problems with them. Microsoft History Support: Post .Net 3.5 sp1 Microsoft’s Script manager supports history for websites using Update panels. This is achieved by enabling the ENABLE HISTORY property for the script manager and then the event “Page_Browser_Navigate” needs to be handled. So whenever the browser buttons are clicked the event is fired and the application can write code to do the navigation. The following articles provide good tutorials on how to do that http://www.asp.net/aspnet-in-net-35-sp1/videos/introduction-to-aspnet-ajax-history http://www.codeproject.com/KB/aspnet/ajaxhistorymanagement.aspx And Microsoft api internally creates an IFrame and changes the bookmark of the url. Unfortunately this has a bug and it does not work in Ie6 and 7 which are the major browsers but it works in ie8 and Firefox. And Microsoft has apparently fixed this bug in .Net 4.0. Following is the blog http://weblogs.asp.net/joshclose/archive/2008/11/11/asp-net-ajax-addhistorypoint-bug.aspx For solutions which are still running on .net 3.5 sp1 there is no solution which Microsoft offers so there is  are two way to solve this o   Disable the back button. o   Develop custom solution.   Disable back button Even though this might look like a very simple thing to do there are issues around doing this  because there is no event which can be manipulated from the javascript. The browser does not provide an api to do this. So most of the technical solution on internet offer work arounds like doing a history.forward(1) so that even if the user clicks a back button the destination page redirects the user to the original page. This is not a good customer experience and does not work for asp.net website where there are different views in the same page. There are other ways around detecting the window unload events and writing code there. So there are 2 events onbeforeUnload and onUnload and we can write code to show a confirmation message to the user. If we write code in onUnLoad then we can only show a message but it is too late to stop the navigation. And if we write on onBeforeUnLoad we can stop the navigation if the user clicks cancel but this event would be triggered for all AJAX calls and hyperlinks where the href is anything other than #. We can do this but the website has to be checked properly to ensure there are no links where href is not # otherwise the user would see a popup message saying “you are leaving the website”. Believe me after doing a lot of research on the back button disable I found it easier to support it rather than disabling the button. So I am going to discuss a solution which work  using jQuery with some tweaking. Custom Solution JQuery already provides an api to manage the history of a AJAX website - http://plugins.jquery.com/project/history We need to integrate this with Microsoft Page request manager so that both of them work in tandem. The page state is maintained in the cookie so that it can be passed to the server and I used jQuery cookie plug in for that – http://plugins.jquery.com/node/1386/release Firstly when the page loads there is a need to hook up all the events on the page which needs to cause browser history and following is the code to that. jQuery(document).ready(function() {             // Initialize history plugin.             // The callback is called at once by present location.hash.             jQuery.history.init(pageload);               // set onlick event for buttons             jQuery("a[@rel='history']").click(function() {                 //                 var hash = this.page;                 hash = hash.replace(/^.*#/, '');                 isAsyncPostBack = true;                 // moves to a new page.                 // pageload is called at once.                 jQuery.history.load(hash);                 return true;             });         }); The above scripts basically gets all the DOM objects which have the attribute rel=”history” and add the event. In our test page we have the link button  which has the attribute rel set to history. <asp:LinkButton ID="Previous" rel="history" runat="server" onclick="PreviousOnClick">Previous</asp:LinkButton> <asp:LinkButton ID="AsyncPostBack" rel="history" runat="server" onclick="NextOnClick">Next</asp:LinkButton> <asp:LinkButton ID="HistoryLinkButton" runat="server" style="display:none" onclick="HistoryOnClick"></asp:LinkButton>   And you can see that there is an hidden HistoryLinkButton which used to send a sever side postback in case of browser back or previous buttons. And note that we need to use display:none and not visible= false because asp.net AJAX would disallow any post backs if visible=false. And in general the pageload event get executed on the client side when a back or forward is pressed and the function is shown below function pageload(hash) {                   if (hash) {                         if (!isAsyncPostBack) {                           jQuery.cookie("page", hash);                     __doPostBack("HistoryLinkButton", "");                 }                isAsyncPostBack = false;                             } else {                 // start page             jQuery("#load").empty();             }         }   As you can see in case there is an hash in the url we are basically do an asp.net AJAX post back using the following statement __doPostBack("HistoryLinkButton", ""); So whenever the user clicks back or forward the post back happens using the event statement we provide and Previous event code is invoked in the code behind.  We need to have the code to use the pageId present in the url to change the page content. And there is an important thing to note – because the hash is worked out using the pageId’s there is a need to recalculate the hash after every AJAX post back so following code is plugged in function ReWorkHash() {             jQuery("a[@rel='history']").unbind("click");             jQuery("a[@rel='history']").click(function() {                 //                 var hash = jQuery(this).attr("page");                 hash = hash.replace(/^.*#/, '');                 jQuery.cookie("page", hash);                 isAsyncPostBack = true;                                   // moves to a new page.                 // pageload is called at once.                 jQuery.history.load(hash);                 return true;             });        }   This code is executed from the code behind using ScriptManager RegisterClientScriptBlock as shown below –       ScriptManager.RegisterClientScriptBlock(this, typeof(_Default), "Recalculater", "ReWorkHash();", true);   A sample application is available to be downloaded at the following location – http://techconsulting.vpscustomer.com/Source/HistoryTest.zip And a working sample is available at – http://techconsulting.vpscustomer.com/Samples/Default.aspx

    Read the article

  • Set focus on div contenteditable element

    - by sanceray3
    Hi all, I try to explain my problem, because I really need your help. I have a <div contenteditable=true> where I define by a WYSIWYG some elements. For example <p>,<h1>, etc. I would like to put directly the focus on one of this elements. For example on <p id="p_test">. But it seems that focus() function doesn't work on <div> elements, <p> elements... Is there a another means to define the focus in my case ? Thank you very much for your help !

    Read the article

  • AJAX Return Problem from data sent via jQuery.ajax

    - by Anthony Garand
    I am trying to receive a json object back from php after sending data to the php file from the js file. All I get is undefined. Here are the contents of the php and js file. data.php <?php $action = $_GET['user']; $data = array( "first_name" = "Anthony", "last_name" = "Garand", "email" = "[email protected]", "password" = "changeme"); switch ($action) { case '[email protected]': echo $_GET['callback'] . '('. json_encode($data) . ');'; break; } ? core.js $(document).ready(function(){ $.ajax({ url: "data.php", data: {"user":"[email protected]"}, context: document.body, data: "jsonp", success: function(data){renderData(data);} }); }); function renderData(data) { document.write(data.first_name); }

    Read the article

  • QNetworkAccessManager timeout.

    - by Umesha MS
    Hi, Presently I am working on an application which sends and receives file from remote server. To do network operation I am using QNetworkAccessManager. To upload a file I am using QNetworkAccessManager::put() and to download I am using QNetworkAccessManager::get() functions. While uploading a file I will initialize a timer with time out of 15 sec. if I upload a small file it will complete it within the time out period. But if I try to upload a file which is very large in size get time out. So how to decide time out for uploading of large file. Same in case of downloading of a large file. I get file in chunk by chunk in readyread() signal. Here also if I download a large file I get time out. So how to decide time out for uploading of large file.

    Read the article

  • How to organize Python modules for PyPI to support 2.x and 3.x

    - by Craig McQueen
    I have a Python module that I would like to upload to PyPI. So far, it is working for Python 2.x. It shouldn't be too hard to write a version for 3.x now. But, after following guidelines for making modules in these places: Distributing Python Modules The Hitchhiker’s Guide to Packaging it's not clear to me how to support multiple source distributions for different versions of Python, and it's not clear if/how PyPI could support it. I envisage I would have separate code for: 2.x 2.6 (maybe, as a special case to use the new buffer API) 3.x How is it possible to set up a Python module in PyPI so that someone can do: easy_install modulename and it will install the right thing whether the user is using 2.x or 3.x?

    Read the article

  • Is SiteCore slow and buggy?

    - by Larsenal
    I've seen plenty of negative comments regarding performance and general bugginess. However, to be fair, most of these look like they were within the v5.3 timeframe. Have they fixed all of those issues in v6.0? Is it an excellent product? Some examples of the complaints: Maybe it’s just a case of user error, but this guy says, “some pages take as much as 20s to render…” Source Here, in the comments, one fellow remaks, “Sitecore backend is incredible slow. Sitecore developement is really pain, it takes from 2 minutes to start sitecore and many many seconds to do small backend operations. They claim to have a quick client, but that is a BIG LIE. All developers in my company really hate sitecore for being so slow.” Source Another search yielded, “Sitecore’s users listed three issues as number one: licensing, the server as a resource hog, and the site’s slow responsiveness.” Source

    Read the article

  • Problem using Flot charts on a jQtouch web site

    - by hairbymaurice
    Hiiii I have a jQtouch site in dev and i would like to use a chart on it, to me Flot looks like the best way to do this (prettiest!) However if i implement flot on the site i get the following error: Invalid dimensions for plot, width = 0, height = 0 If i comment out the style sheet ../jqtouch/jqtouch.min.css the flot chart works just fine. This i think has something to do with the fact that you cannot use flot inside a div that has display:none From the Flot readme Blockquote Make sure that the placeholder isn't within something with a display:none CSS property - in that case, Flot has trouble measuring label dimensions which results in garbled looks and might have trouble measuring the placeholder dimensions which is fatal (it'll throw an exception). Does anyone now if i can work around this/fix this so flot and jQtouch work together? Thanks Hairby

    Read the article

  • Using Toad with 64bit Oracle Client and Windows 7 64bit Operating System

    - by Andy5
    After downloading the latest version of Toad for Windows 7 64bit, I am struggling to get it to connect to the database using the existing full Oracle Client that is already on the desktop. The Oracle Client that is there is a 64bit version and is version 12c. When running Toad it says that there is no Oracle Client installed. All of the environment variables have been set up to point to the Oracle Client I note from the attached link that when using Toad in a 64bit os that you have to use a 32bit client? Is this still the case? If not how do I get it to use the Oracle Client? I cannot use another version because of the application that is using it needs that version. http://www.quest.com/toad-development-suite-for-oracle/ Thanks

    Read the article

  • Android: onKeyDown() problem

    - by niko
    Hi, I would like to create a photo/video capture application. I have created a CaptureView class which extends SurfaceView and placed it in the main form. The main form's activity has onCreateOptionsMenu() method which creates a menu. The menu worked fine but then I tried to implement a method onKeyDown: @Override public boolean onKeyDown(int keyCode, KeyEvent event) { if(event.getAction() == KeyEvent.ACTION_DOWN) { switch(keyCode) { case KeyEvent.KEYCODE_CAMERA: videoPreview.TakePicture(); return true; } } return super.onKeyDown(keyCode, event); } The menu doesn't appear anymore and the method doesn't catch onKeyDown event. Does anyone know what could be the reason for this issue? Thanks!

    Read the article

  • How to tell when a UISwitch inside of a UITableViewCell has been tapped?

    - by RexOnRoids
    How to tell when a UISwitch inside of a UITableViewCell has been tapped? My UISwitch is set up inside of the cell (generic cell) like this: UISwitch *mySwitch = [[[UISwitch alloc] initWithFrame:CGRectZero] autorelease]; [cell addSubview:mySwitch]; cell.accessoryView = mySwitch; And I am trying to detect a tap like this (but its not working): - (void)tableView:(UITableView *)tableView accessoryButtonTappedForRowWithIndexPath:(NSIndexPath *)indexPath { NSUserDefaults *prefs; if(indexPath.section == 1){ switch(indexPath.row) { case 0: NSLog(@"Tapped Login Switch"); break; default: break; } } }

    Read the article

  • Ruby on Rails deployment, on "thin" server with lot of attachments

    - by Horace Ho
    A lot of PDFs are stored inside MySQL as a BLOB field for each PDF file. The average file size is 500K each. The Rails app will stream the :binary data as file downloads, where there is a user click on the download link. Assume there is a maximum of 5 users downloading 5 PDFs concurrently, what kind of deployment setup parameters I should be aware of? e.g. for the case of thin: thin start --servers 3 whether --servers 3 is good enough (or 5 or more is needed) for the above example? The 2nd question is whether 'thin' a capable solution? Thanks!

    Read the article

  • [Android] Change language settings (locale) for the device

    - by raychenon
    Hi, I know it's possible to have multiple languages in a single application through the res/string and depending on Locale. Here is a case http://stackoverflow.com/questions/2078289/android-controling-the-user-language Now how can I change the language in the phone ? Like I'd do by Menu Settings Language & Keyboard Select locale languages Is there some real code to access to these settings ? Or should I create intent for a shortcut to the language settings. Please post some code Edit : With Locale class developer.android.com/intl/fr/reference/java/util/Locale.html The constructor is at least Locale(String language) The input is language. How can you retrieve the current language used on the device ?

    Read the article

  • Inheritance Mapping Strategies with Entity Framework Code First CTP5: Part 3 – Table per Concrete Type (TPC) and Choosing Strategy Guidelines

    - by mortezam
    This is the third (and last) post in a series that explains different approaches to map an inheritance hierarchy with EF Code First. I've described these strategies in previous posts: Part 1 – Table per Hierarchy (TPH) Part 2 – Table per Type (TPT)In today’s blog post I am going to discuss Table per Concrete Type (TPC) which completes the inheritance mapping strategies supported by EF Code First. At the end of this post I will provide some guidelines to choose an inheritance strategy mainly based on what we've learned in this series. TPC and Entity Framework in the Past Table per Concrete type is somehow the simplest approach suggested, yet using TPC with EF is one of those concepts that has not been covered very well so far and I've seen in some resources that it was even discouraged. The reason for that is just because Entity Data Model Designer in VS2010 doesn't support TPC (even though the EF runtime does). That basically means if you are following EF's Database-First or Model-First approaches then configuring TPC requires manually writing XML in the EDMX file which is not considered to be a fun practice. Well, no more. You'll see that with Code First, creating TPC is perfectly possible with fluent API just like other strategies and you don't need to avoid TPC due to the lack of designer support as you would probably do in other EF approaches. Table per Concrete Type (TPC)In Table per Concrete type (aka Table per Concrete class) we use exactly one table for each (nonabstract) class. All properties of a class, including inherited properties, can be mapped to columns of this table, as shown in the following figure: As you can see, the SQL schema is not aware of the inheritance; effectively, we’ve mapped two unrelated tables to a more expressive class structure. If the base class was concrete, then an additional table would be needed to hold instances of that class. I have to emphasize that there is no relationship between the database tables, except for the fact that they share some similar columns. TPC Implementation in Code First Just like the TPT implementation, we need to specify a separate table for each of the subclasses. We also need to tell Code First that we want all of the inherited properties to be mapped as part of this table. In CTP5, there is a new helper method on EntityMappingConfiguration class called MapInheritedProperties that exactly does this for us. Here is the complete object model as well as the fluent API to create a TPC mapping: public abstract class BillingDetail {     public int BillingDetailId { get; set; }     public string Owner { get; set; }     public string Number { get; set; } }          public class BankAccount : BillingDetail {     public string BankName { get; set; }     public string Swift { get; set; } }          public class CreditCard : BillingDetail {     public int CardType { get; set; }     public string ExpiryMonth { get; set; }     public string ExpiryYear { get; set; } }      public class InheritanceMappingContext : DbContext {     public DbSet<BillingDetail> BillingDetails { get; set; }              protected override void OnModelCreating(ModelBuilder modelBuilder)     {         modelBuilder.Entity<BankAccount>().Map(m =>         {             m.MapInheritedProperties();             m.ToTable("BankAccounts");         });         modelBuilder.Entity<CreditCard>().Map(m =>         {             m.MapInheritedProperties();             m.ToTable("CreditCards");         });                 } } The Importance of EntityMappingConfiguration ClassAs a side note, it worth mentioning that EntityMappingConfiguration class turns out to be a key type for inheritance mapping in Code First. Here is an snapshot of this class: namespace System.Data.Entity.ModelConfiguration.Configuration.Mapping {     public class EntityMappingConfiguration<TEntityType> where TEntityType : class     {         public ValueConditionConfiguration Requires(string discriminator);         public void ToTable(string tableName);         public void MapInheritedProperties();     } } As you have seen so far, we used its Requires method to customize TPH. We also used its ToTable method to create a TPT and now we are using its MapInheritedProperties along with ToTable method to create our TPC mapping. TPC Configuration is Not Done Yet!We are not quite done with our TPC configuration and there is more into this story even though the fluent API we saw perfectly created a TPC mapping for us in the database. To see why, let's start working with our object model. For example, the following code creates two new objects of BankAccount and CreditCard types and tries to add them to the database: using (var context = new InheritanceMappingContext()) {     BankAccount bankAccount = new BankAccount();     CreditCard creditCard = new CreditCard() { CardType = 1 };                      context.BillingDetails.Add(bankAccount);     context.BillingDetails.Add(creditCard);     context.SaveChanges(); } Running this code throws an InvalidOperationException with this message: The changes to the database were committed successfully, but an error occurred while updating the object context. The ObjectContext might be in an inconsistent state. Inner exception message: AcceptChanges cannot continue because the object's key values conflict with another object in the ObjectStateManager. Make sure that the key values are unique before calling AcceptChanges. The reason we got this exception is because DbContext.SaveChanges() internally invokes SaveChanges method of its internal ObjectContext. ObjectContext's SaveChanges method on its turn by default calls AcceptAllChanges after it has performed the database modifications. AcceptAllChanges method merely iterates over all entries in ObjectStateManager and invokes AcceptChanges on each of them. Since the entities are in Added state, AcceptChanges method replaces their temporary EntityKey with a regular EntityKey based on the primary key values (i.e. BillingDetailId) that come back from the database and that's where the problem occurs since both the entities have been assigned the same value for their primary key by the database (i.e. on both BillingDetailId = 1) and the problem is that ObjectStateManager cannot track objects of the same type (i.e. BillingDetail) with the same EntityKey value hence it throws. If you take a closer look at the TPC's SQL schema above, you'll see why the database generated the same values for the primary keys: the BillingDetailId column in both BankAccounts and CreditCards table has been marked as identity. How to Solve The Identity Problem in TPC As you saw, using SQL Server’s int identity columns doesn't work very well together with TPC since there will be duplicate entity keys when inserting in subclasses tables with all having the same identity seed. Therefore, to solve this, either a spread seed (where each table has its own initial seed value) will be needed, or a mechanism other than SQL Server’s int identity should be used. Some other RDBMSes have other mechanisms allowing a sequence (identity) to be shared by multiple tables, and something similar can be achieved with GUID keys in SQL Server. While using GUID keys, or int identity keys with different starting seeds will solve the problem but yet another solution would be to completely switch off identity on the primary key property. As a result, we need to take the responsibility of providing unique keys when inserting records to the database. We will go with this solution since it works regardless of which database engine is used. Switching Off Identity in Code First We can switch off identity simply by placing DatabaseGenerated attribute on the primary key property and pass DatabaseGenerationOption.None to its constructor. DatabaseGenerated attribute is a new data annotation which has been added to System.ComponentModel.DataAnnotations namespace in CTP5: public abstract class BillingDetail {     [DatabaseGenerated(DatabaseGenerationOption.None)]     public int BillingDetailId { get; set; }     public string Owner { get; set; }     public string Number { get; set; } } As always, we can achieve the same result by using fluent API, if you prefer that: modelBuilder.Entity<BillingDetail>()             .Property(p => p.BillingDetailId)             .HasDatabaseGenerationOption(DatabaseGenerationOption.None); Working With The Object Model Our TPC mapping is ready and we can try adding new records to the database. But, like I said, now we need to take care of providing unique keys when creating new objects: using (var context = new InheritanceMappingContext()) {     BankAccount bankAccount = new BankAccount()      {          BillingDetailId = 1                          };     CreditCard creditCard = new CreditCard()      {          BillingDetailId = 2,         CardType = 1     };                      context.BillingDetails.Add(bankAccount);     context.BillingDetails.Add(creditCard);     context.SaveChanges(); } Polymorphic Associations with TPC is Problematic The main problem with this approach is that it doesn’t support Polymorphic Associations very well. After all, in the database, associations are represented as foreign key relationships and in TPC, the subclasses are all mapped to different tables so a polymorphic association to their base class (abstract BillingDetail in our example) cannot be represented as a simple foreign key relationship. For example, consider the the domain model we introduced here where User has a polymorphic association with BillingDetail. This would be problematic in our TPC Schema, because if User has a many-to-one relationship with BillingDetail, the Users table would need a single foreign key column, which would have to refer both concrete subclass tables. This isn’t possible with regular foreign key constraints. Schema Evolution with TPC is Complex A further conceptual problem with this mapping strategy is that several different columns, of different tables, share exactly the same semantics. This makes schema evolution more complex. For example, a change to a base class property results in changes to multiple columns. It also makes it much more difficult to implement database integrity constraints that apply to all subclasses. Generated SQLLet's examine SQL output for polymorphic queries in TPC mapping. For example, consider this polymorphic query for all BillingDetails and the resulting SQL statements that being executed in the database: var query = from b in context.BillingDetails select b; Just like the SQL query generated by TPT mapping, the CASE statements that you see in the beginning of the query is merely to ensure columns that are irrelevant for a particular row have NULL values in the returning flattened table. (e.g. BankName for a row that represents a CreditCard type). TPC's SQL Queries are Union Based As you can see in the above screenshot, the first SELECT uses a FROM-clause subquery (which is selected with a red rectangle) to retrieve all instances of BillingDetails from all concrete class tables. The tables are combined with a UNION operator, and a literal (in this case, 0 and 1) is inserted into the intermediate result; (look at the lines highlighted in yellow.) EF reads this to instantiate the correct class given the data from a particular row. A union requires that the queries that are combined, project over the same columns; hence, EF has to pad and fill up nonexistent columns with NULL. This query will really perform well since here we can let the database optimizer find the best execution plan to combine rows from several tables. There is also no Joins involved so it has a better performance than the SQL queries generated by TPT where a Join is required between the base and subclasses tables. Choosing Strategy GuidelinesBefore we get into this discussion, I want to emphasize that there is no one single "best strategy fits all scenarios" exists. As you saw, each of the approaches have their own advantages and drawbacks. Here are some rules of thumb to identify the best strategy in a particular scenario: If you don’t require polymorphic associations or queries, lean toward TPC—in other words, if you never or rarely query for BillingDetails and you have no class that has an association to BillingDetail base class. I recommend TPC (only) for the top level of your class hierarchy, where polymorphism isn’t usually required, and when modification of the base class in the future is unlikely. If you do require polymorphic associations or queries, and subclasses declare relatively few properties (particularly if the main difference between subclasses is in their behavior), lean toward TPH. Your goal is to minimize the number of nullable columns and to convince yourself (and your DBA) that a denormalized schema won’t create problems in the long run. If you do require polymorphic associations or queries, and subclasses declare many properties (subclasses differ mainly by the data they hold), lean toward TPT. Or, depending on the width and depth of your inheritance hierarchy and the possible cost of joins versus unions, use TPC. By default, choose TPH only for simple problems. For more complex cases (or when you’re overruled by a data modeler insisting on the importance of nullability constraints and normalization), you should consider the TPT strategy. But at that point, ask yourself whether it may not be better to remodel inheritance as delegation in the object model (delegation is a way of making composition as powerful for reuse as inheritance). Complex inheritance is often best avoided for all sorts of reasons unrelated to persistence or ORM. EF acts as a buffer between the domain and relational models, but that doesn’t mean you can ignore persistence concerns when designing your classes. SummaryIn this series, we focused on one of the main structural aspect of the object/relational paradigm mismatch which is inheritance and discussed how EF solve this problem as an ORM solution. We learned about the three well-known inheritance mapping strategies and their implementations in EF Code First. Hopefully it gives you a better insight about the mapping of inheritance hierarchies as well as choosing the best strategy for your particular scenario. Happy New Year and Happy Code-Firsting! References ADO.NET team blog Java Persistence with Hibernate book a { color: #5A99FF; } a:visited { color: #5A99FF; } .title { padding-bottom: 5px; font-family: Segoe UI; font-size: 11pt; font-weight: bold; padding-top: 15px; } .code, .typeName { font-family: consolas; } .typeName { color: #2b91af; } .padTop5 { padding-top: 5px; } .padTop10 { padding-top: 10px; } .exception { background-color: #f0f0f0; font-style: italic; padding-bottom: 5px; padding-left: 5px; padding-top: 5px; padding-right: 5px; }

    Read the article

  • TDD - How to start really thinking TDD?

    - by user74825
    I have been reading about Agile, XP methodologies and TDDs. I have been in projects which states it needs to do TDD, but most of the tests are somehow integration tests or during the course of project TDD is forgotten in effort to finish codes faster. So, as far as my case goes, I have written unit tests, but I find myself going to start writing code first instead of writing a test. I feel there's a thought / design / paradigm change which is actually huge. So, though one really believes in TDD, you actually end up going back old style because of time pressure / project deliverables. I have few classes where I have pure unit tested code, but I can't seem to continue with the process, when mocks come into picture. Also, I see at times : "isn't it too trivial to write a test for it" syndrome. How do you guys think I should handle this?

    Read the article

  • Silverlight Ftp Upload

    - by Curtis
    Hi I'm working on trying to ftp a file to the server through a silverlight application. Where the location to upload the file on server file system, exists outside the sandbox area for the web server. In this case the web server root exists at "C:\test\www\" and the location to upload the file will exist at "C:\User\Uploads". In this scenerio i'm not sure if Http POST will work (doesn't that use the web server root). I just need to upload the file selected by the user to a different location that may exist outside the sandbox. With silverlight i'm thinking sockets are my last option based on the limited port range for silverlight being 4502-4532. Can i do this using WebClient and Http POST? Can i make an ftp connection through silverlight or javascript?

    Read the article

  • Distributing IronPython applications - how to detect the location of ipyw.exe

    - by Kragen
    I'm thinking of developing a small application using Iron python, however I want to distribute my app to non-techies and so ideally I want to be able to give them a standard shortcut to my application along with the instructions that they need to install IronPython first. If possible I even want my shortcut to detect if IronPython is not present and display a suitable warning if this is the case (which I can do using a simple VbScript) The trouble is that IronPython doesn't place itself in the %PATH% environment variable, and so if IronPython is installed to a nonstandard location my shortcut don't work. Now I could also tell my users "If you install IronPython to a different location you need to go and edit this shortcut and...", but this is all getting far too technical for my target audience. Is there any foolproof way of distributing my IronPython dependent app?

    Read the article

< Previous Page | 456 457 458 459 460 461 462 463 464 465 466 467  | Next Page >