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  • Oddities in Linq-to-SQL generated code related to property change/changing events

    - by Lasse V. Karlsen
    I'm working on creating my own Linq-to-Sql generated classes in order to learn the concepts behind it all. I have some questions, if anyone knows the answer to one or more of these I'd be much obliged. The code below, and thus the questions, are from looking at code generated by creating a .DBML file in the Visual Studio 2010 designer, and inspecting the .Designer.cs file afterwards. 1. Why is INotifyPropertyChanging not passing the property name The event raising method is defined like this: protected virtual void SendPropertyChanging() Why isn't the name of the property that is changing passed to the event here? It is defined to be part of the EventArgs descendant that is passed to the event handler, but the method only passes an empty such value to it. 2. Why are the EntitySet<X> attach/detach methods not raising property changed? For an EntitySet<X> reference, the following two methods are generated: private void attach_EmailAddress1s(EmailAddress1 entity) { this.SendPropertyChanging(); entity.Person1 = this; } private void detach_EmailAddress1s(EmailAddress1 entity) { this.SendPropertyChanging(); entity.Person1 = null; } Why isn't SendPropertyChanged also called here? I'm sure I have more questions later, but for now these will suffice :)

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  • linq to xml selection/update

    - by gleasonomicon
    If I have the following xml, how would I use linq to xml blank out the date fields in each video node? I wanted to do it for the purpose of a comparison in a unit test. <?xml version="1.0" encoding="utf-8" standalone="yes" ?> <main> <videos> <video> <id>00000000-0000-0000-0000-000000000000</id> <title>Video Title</title> <videourl>http://sample.com</videourl> <thumbnail>http://sample.com</thumbnail> <dateCreated>2011-01-12T18:54:56.7318386-05:00</dateCreated> <dateModified>2011-02-12T18:54:56.7318386-05:00</dateModified> <Numbers> <Number>28</Number> <Number>78</Number> </Numbers> </video> <video> <id>00000000-0000-0000-0000-000000000000</id> <title>Video Title</title> <videourl>http://sample.com</videourl> <thumbnail>http://sample.com</thumbnail> <dateCreated>2011-01-12T18:54:56.7318386-05:00</dateCreated> <dateModified>2011-02-12T18:54:56.7318386-05:00</dateModified> <Numbers> <Number>28</Number> <Number>78</Number> </Numbers> </video> </videos>

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  • Recursive search Linq to xml

    - by Raj Esh
    this is my sample xml. <Messages> <Conversation> <id>Z100</id> <ReplyToId></ReplyToId> <Message>Topic</Message> </Conversation> <Conversation> <id>A100</id> <ReplyToId></ReplyToId> <Message>This is a test</Message> </Conversation> <Conversation> <id>M100</id> <ReplyToId>A100</ReplyToId> <Message>What kind of test</Message> </Conversation> <Conversation> <id>A200</id> <ReplyToId>M100</ReplyToId> <Message>Stage 1</Message> </Conversation> <Conversation> <id>M200</id> <ReplyToId>A200</ReplyToId> <Message>Test result for </Message> </Conversation> </Messages> How to get the conversation list based on id using linq in C#. Say for example, If i want to get the conversation for id "A100" which has a link to other conversation based on ReplyToid.

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  • Using LINQ to isolate a particular obect from a list of objects

    - by dezkev
    Hello All, I am trying my hand at making an invaders clone. there are 30 aliens arranged in a 5x 6 matrix on screen. I need to give the bottom most alien the ability to fire a shot. I am using LINQ to group the aliens into 5 groups based on Location.X and then sort the groups descending.I then need to choose one of the groups ( that gives me 5 groups) and select the First alien in the group and use it;s coordinate to fire a shot. My code below ,well ,works , but aliens in ANY row are merrily firing shots- not just the bottom most. Pl look at my code below and tell me whats wrong. (r = an instance of the Random class, all aliens are in a list called invaders). { var query = (from inv in invaders group inv by inv.Location.X into invgroup orderby invgroup.Key descending select invgroup).ToList(); var invfirst = query[r.Next(query.Count)].First(); invaderShots.Add(new Shot( new Point(invfirst.Area.X + invfirst.Area.Width / 2, invfirst.Area.Y + invfirst.Area.Height + 5), displayrect, Shot.Direction.Down)); }

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  • C# Linq to SQL connection string (newbie)

    - by Chris'o
    i am a new linq to sql learner and this is my very first attempt to create a data viewer program. The idea is simple, i'd like to create a software that is able to view content of a table in a database. That's it. I got an early problem here already and i have seen many tutes and articles online but I still cant fix the bug. Here is my code: static void Main(string[] args) { string cs = "Data Source=localhost;Initial Catalog=somedb;Integrated Security=SSPI;"; var db = new DataClasses1DataContext(cs); db.Connection.Open(); foreach (var b in db.Mapping.GetTables()) Console.WriteLine(b.TableName); Console.ReadKey(true); } When I tried to check db.connection.equals(null); it returns false, so i thought i have connected successfully to the database since there is no error at all. But the code above doesn't print anything out to the screen. I kind of lost and don't know what's going on here. Does anyone know what is going wrong here?

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  • Problem with LINQ to XML and Namespaces

    - by abtcabe
    I am having problems with working with a third party XML string that contains a Namespace with LINQ to XML. In the below code everything works find. I am able to select the xElement (xEl1) and update its value. 'Example Without Namespace Dim XmlWithOutNs = _ <?xml version="1.0"?> <RATABASECALC> <RATEREQUEST> <ANCHOR> <DATABASENAME>DatabaseName</DATABASENAME> <DATABASEPW>DatabasePw</DATABASEPW> </ANCHOR> </RATEREQUEST> </RATABASECALC> Dim xEl1 = XmlWithOutNs...<DATABASEPW>.FirstOrDefault If xEl1 IsNot Nothing Then xEl1.Value = "test" End If However, in the below code the xElement (xEl2) returns Nothing. The only difference is the Namespace (xmlns="http://www.cgi.com/Ratabase) 'Example With Namespace Dim XmlWithNs = _ <?xml version="1.0"?> <RATABASECALC xmlns="http://www.cgi.com/Ratabase"> <RATEREQUEST> <ANCHOR> <DATABASENAME>DatabaseName</DATABASENAME> <DATABASEPW>DatabasePw</DATABASEPW> </ANCHOR> </RATEREQUEST> </RATABASECALC> Dim xEl2 = XmlWithNs...<DATABASEPW>.FirstOrDefault If xEl2 IsNot Nothing Then xEl2.Value = "test" End If So my questions are: 1. Why is this happening? 2. How do I resolve this issue?

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  • Retrieve nested list from XDocument with LINQ

    - by twreid
    Ok I want my link query to return a list of users. Below is the XML <section type="Users"> <User type="WorkerProcessUser"> <default property="UserName" value="Main"/> <default property="Password" value=""/> <default property="Description" value=""/> <default property="Group" value=""/> </User> <User type="AnonymousUser"> <default property="UserName" value="Second"/> <default property="Password" value=""/> <default property="Description" value=""/> <default property="Group" value=""/> </User> </section> And my current LINQ Query that doesn't work. doc is an XDocument var users = (from iis in doc.Descendants("section") where iis.Attribute("type").Value == "Users" from user in iis.Elements("User") from prop in user.Descendants("default") select new { Type = user.Attribute("type").Value, UserName = prop.Attribute("UserName").Value }); This does not work can anyone tell me what I need to fix? Here is my second attempt after fixing for the wrong property name. However this one does not seem to enumerate the UserName value for me when I try to use it or at least when I try to write it to the console. Also this returns 8 total results I should only have 2 results as I only have 2 users. (from iis in doc.Descendants("section") where iis.Attribute("type").Value == "Users" from user in iis.Elements("User") from prop in user.Descendants("default") select new { Type = user.Attribute("type").Value, UserName = (from name in prop.Attributes("property") where name.Value == "UserName" select name.NextAttribute.Value).ToString() });

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  • LINQ To SQL Dynamic Select

    - by mcass20
    Can someone show me how to indicate which columns I would like returned at run-time from a LINQ To SQL statement? I am allowing the user to select items in a checkboxlist representing the columns they would like displayed in a gridview that is bound to the results of a L2S query. I am able to dynamically generate the WHERE clause but am unable to do the same with the SELECT piece. Here is a sample: var query = from log in context.Logs select log; query = query.Where(Log => Log.Timestamp > CustomReport.ReportDateStart); query = query.Where(Log => Log.Timestamp < CustomReport.ReportDateEnd); query = query.Where(Log => Log.ProcessName == CustomReport.ProcessName); foreach (Pair filter in CustomReport.ExtColsToFilter) { sExtFilters = "<key>" + filter.First + "</key><value>" + filter.Second + "</value>"; query = query.Where(Log => Log.FormattedMessage.Contains(sExtFilters)); }

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  • LINQ Sorting - First three need to be different manufacturers

    - by Rob
    My OM has a 'product' object. Each product has a 'manufacturer id' (property, integer). When I have a list of products to display, the first three are displayed as the 'featured products'. The list is already sorted in a specific sort order, putting the 'featured' products first in the list. However, I now need to ensure the featured products in the listing are from different Manufacturers. I want to have a method to call to do this re-sorting. Trying to utilize LINQ to to the querying of the input 'products' and the 'results' public List<Product> SetFeatures(List<Product> products, int numberOfFeatures) { List<Product> result; // ensure the 2nd product is different manufacturer than the first .... // ensure the 3rd product is a different manufacturer than the first two... // ... etc ... for the numberOfFeatures return result; } Thanks in advance.

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  • How to filter List<T> with LINQ and Reflection

    - by Ehsan Sajjad
    i am getting properties via reflection and i was doing like this to iterate on the list. private void HandleListProperty(object oldObject, object newObject, string difference, PropertyInfo prop) { var oldList = prop.GetValue(oldObject, null) as IList; var newList = prop.GetValue(newObject, null) as IList; if (prop.PropertyType == typeof(List<DataModel.ScheduleDetail>)) { List<DataModel.ScheduleDetail> ScheduleDetailsOld = oldList as List<DataModel.ScheduleDetail>; List<DataModel.ScheduleDetail> ScheduleDetailsNew = newList as List<DataModel.ScheduleDetail>; var groupOldSchedules = ScheduleDetailsOld .GroupBy(x => x.HomeHelpID) .SelectMany(s => s.DistinctBy(d => d.HomeHelpID) .Select(h => new { h.HomeHelpID, h.HomeHelpName })); } } Now i am making it generic because there will be coming different types of Lists and i don't want to put if conditions this way i want to write generic code to handle any type of list. I came up with this way: private void HandleListProperty(object oldObject, object newObject, string difference, PropertyInfo prop) { var oldList = prop.GetValue(oldObject, null) as IList; var newList = prop.GetValue(newObject, null) as IList; var ListType = prop.PropertyType; var MyListInstance = Activator.CreateInstance(ListType); MyListInstance = oldList; } i am able to get the items in MyListInstance but as the type will come at runtime i am not getting how to write linq query to filter them, any ideah how to do.

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  • How to select a single object using Linq in vb.net

    - by Hucker
    I have done a lot of searching to what appears to be a simple LINQ problem but I can't figure out how to do grab an object out of a collection that has a specified minimum (or max value) without resorting to a sort like this: > dim customers= GetCustomers() > > dim youngest = (From c in customers > Order By c.age Ascending).ToList.First This (untested code) structure works fine with the exception that the entire customer array must be sorted and placed into a list for the only purpose of extracting the first value. That can't be the best way to get the minimum! Note that I want the whole c record in this case, not the minumum age of a customer that can be done like this (a typical example): > dim customers= GetCustomers() > > dim youngest = (From c in customers > Select c.age).Min Or even > dim customers= GetCustomers() > > dim youngest = (From c in customers > Select c).Min(Function(x) x.age) I can't for the life of me figure out how to get the whole object (or even the index) without resorting to the sort...

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  • Xml updating with linq not working when quering

    - by user1734230
    I have problem i'm trying to update a specific part of the XML with the linq query but it doesn't work. So i an xml file: <?xml version="1.0" encoding="utf-8"?> <DesignConfiguration> <Design name="CSF_Packages"> <SourceFolder>C:\CSF_Packages</SourceFolder> <DestinationFolder>C:\Documents and Settings\xxx</DestinationFolder> <CopyLookups>True</CopyLookups> <CopyImages>False</CopyImages> <ImageSourceFolder>None</ImageSourceFolder> <ImageDesinationFolder>None</ImageDesinationFolder> </Design> </DesignConfiguration> I want to select the part where the part where there is Design name="somethning" and get the descendants and then update the descendants value that means this part: <SourceFolder>C:\CSF_Packages</SourceFolder> <DestinationFolder>C:\Documents and Settings\xxx</DestinationFolder> <CopyLookups>True</CopyLookups> <CopyImages>False</CopyImages> <ImageSourceFolder>None</ImageSourceFolder> <ImageDesinationFolder>None</ImageDesinationFolder> I have this code: XDocument configXml = XDocument.Load(configXMLFileName); var updateData = configXml.Descendants("DesignConfiguration").Elements().Where(el => el.Name == "Design" && el.Attribute("name").Value.Equals("AFP_GRAFIKA")).FirstOrDefault(); configXml.Save(configXMLFileName); I'm getting the null data in the updateData varibale. When I'm trying the Descendat's function through QuickWatch it also returns a null value. When I'm checking the configXML variable it has data that is my whole xml. What am I doing wrong?

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  • LINQ Expression - Dynamic From & Where Clause

    - by chillydk147
    I have the following list of integers that I need to extract varying lists of integers containing numbers from say 2-4 numbers in count. The code below will extract lists with only 2 numbers. var numList = new List<int> { 5, 20, 1, 7, 19, 3, 15, 60, 3, 21, 57, 9 }; var selectedNums = (from n1 in numList from n2 in numList where (n1 > 10) && (n2 > 10) select new { n1, n2 }).ToList(); Is there any way to build up this Linq expression dynamically so that if I wanted lists of 3 numbers it would be compiled as below, this would save me having to package the similar expression inside a different method. var selectedNums = (from n1 in numList from n2 in numList from n3 in numList where (n1 > 10) && (n2 > 10) && (n3 > 10) select new { n1, n2, n3 }).ToList();

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  • LinQ optimization

    - by Budda
    Here is a peace of code: void MyFunc(List<MyObj> objects) { MyFunc1(objects); foreach( MyObj obj in objects.Where(obj1=>obj1.Good)) { // Do Action With Good Object } } void MyFunc1(List<MyObj> objects) { int iGoodCount = objects.Where(obj1=>obj1.Good).Count(); BeHappy(iGoodCount); // do other stuff with 'objects' collection } Here we see that collection is analyzed twice and each time the value of 'Good' property is checked for each member: 1st time when calculating count of good objects, 2nd - when iterating through all good objects. It is desirable to have that optimized, and here is a straightforward solution: before call to MyFunc1 makecreate an additional temporary collection of good objects only (goodObjects, it can be IEnumerable); get count of these objects and pass it as an additional parameter to MyFunc1; in the 'MyFunc' method iterate not through 'objects.Where(...)' but through the 'goodObjects' collection. Not too bad approach (as far as I see), but additional parameter is required to be passed. Question: is there any LinQ out-of-the-box functionality that allows any caching during 1st Where().Count(), remembering a processed collection and use it in the next iteration? Any thoughts are welcome. Thanks.

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  • Something wrong on my very first LINQ to SQL c # code

    - by user334813
    using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; namespace Advanced_LinQ_Query { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private DataClasses1DataContext database = new DataClasses1DataContext(); private void Form1_Load(object sender, EventArgs e) { database.Log= Console.Out; comboBox.SelectedIndex=0; } private void titleBindingNavigatorSaveItem_Click(object sender, EventArgs e) { Validate(); titleBindingSource.EndEdit(); database.SubmitChanges(); comboBox.SelectedIndex=0; } private void comboBox_SelectedIndexChanged(object sender, EventArgs e) { switch (comboBox.SelectedIndex) { case 0: titleBindingSource.DataSource = from Title in database.Titles orderby Title.BookTitle select Title; break; case 1: titleBindingSource.DataSource = from Title in database.Titles where Title.Copyright == "2008" orderby Title.BookTitle select Title; break; case 2: titleBindingSource.DataSource = from Title in database.Titles where Title.BookTitle.EndsWith("How to Program") orderby Title.BookTitle select Title; break; } titleBindingSource.MoveFirst(); } } } no connection seems to built after debugging between Title table in my database (book.mdf) and titleBindingSource! Where is the problem?

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  • How do I select every 6th element from a list (using Linq)

    - by iDog
    Hi, I've got a list of 'double' values. I need to select every 6th record. It's a list of coordinates, where I need to get the minimum and maximum value of every 6th value. List of coordinates (sample): [2.1, 4.3, 1.0, 7.1, 10.6, 39.23, 0.5, ... ] with hundrets of coordinates. Result should look like: [x_min, y_min, z_min, x_max, y_max, z_max] with exactly 6 coordinates. Following code works, but it takes to long to iterate over all coordinates. I'd like to use Linq instead (maybe faster?) for (int i = 0; i < 6; i++) { List<double> coordinateRange = new List<double>(); for (int j = i; j < allCoordinates.Count(); j = j + 6) coordinateRange.Add(allCoordinates[j]); if (i < 3) boundingBox.Add(coordinateRange.Min()); else boundingBox.Add(coordinateRange.Max()); } Any suggestions? Many thanks! Greets!

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  • Linq based generic alternate to Predicate<T>?

    - by Eric
    I have an interface called ICatalog as shown below where each ICatalog has a name and a method that will return items based on a Predicate<Item> function. public interface ICatalog { string Name { get; } IEnumerable<IFamily> GetItems(Predicate<Item> predicate); } A specific implementation of a catalog may be linked to catalogs in various format such as XML, or a SQL database. With an XML catalog I end up deserializing the entire XML file into memory, so testing each item with the predicate function does does not add a whole lot more overhead as it's already in memory. Yet with the SQL implementation I'd rather not retrieve the entire contents of the database into memory, and then filter the items with the predicate function. Instead I'd want to find a way to somehow pass the predicate to the SQL server, or somehow convert it to a SQL query. This seems like a problem that can be solved with Linq, but I'm pretty new to it. Should my interface return IQueryable instead?

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  • How can I combine a LINQ query with an IQueryable<Guid>

    - by John
    I have a LINQ query that uses 1 table + a large number of views. I'd like to be able to write something like this: IQueryable<Guid> mostViewedWriters; switch (datePicker) { case DatePicker.Last12Hours: mostViewedWriters = from x in context.tempMostViewed12Hours select x.GuidId; break; case DatePicker.Last24Hours: mostViewedWriters = from x in context.tempMostViewed12Hours select x.GuidId; break; case DatePicker.Last36Hours: mostViewedWriters = from x in context.tempMostViewed12Hours select x.GuidId; break; } var query = from x1 in context.Articles join x2 in context.Authors on x1.AuthorId == x2.AuthorId join x3 in mostViewedWriters on x2.AuthorId == x3.Id select new { x2.AuthorName, x1.ArticleId, x1.ArticleTitle }; The above C# is pseudo-code written to protect the innocent (me). The gist of the question is this: I have a query that is related to the results of a view. That view, however, could be one of many different views. All the views return the same data type. I thought that I might be able to create an IQueryable that would contain the Ids that I need and use that query. Alas, that effort has stalled.

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  • Succinct LINQ to XML Query

    - by Kent Boogaart
    Assuming you have the following XML: <?xml version="1.0" encoding="utf-8"?> <content> <info> <media> <image> <info> <imageType>product</imageType> </info> <imagedata fileref="http://www.example.com/image1.jpg" /> </image> <image> <info> <imageType>manufacturer</imageType> </info> <imagedata fileref="http://www.example.com/image2.jpg" /> </image> </media> </info> </content> Using LINQ to XML, what is the most succinct, robust way to obtain a System.Uri for an image of a given type? At the moment I have this: private static Uri GetImageUri(XElement xml, string imageType) { return (from imageTypeElement in xml.Descendants("imageType") where imageTypeElement.Value == imageType && imageTypeElement.Parent != null && imageTypeElement.Parent.Parent != null from imageDataElement in imageTypeElement.Parent.Parent.Descendants("imagedata") let fileRefAttribute = imageDataElement.Attribute("fileref") where fileRefAttribute != null && !string.IsNullOrEmpty(fileRefAttribute.Value) select new Uri(fileRefAttribute.Value)).FirstOrDefault(); } This works, but feels way too complicated. Especially when you consider the XPath equivalent. Can anyone point out a better way?

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  • LINQ Many to Many With In or Contains Clause (and a twist)

    - by Chris
    I have a many to many table structure called PropertyPets. It contains a dual primary key consisting of a PropertyID (from a Property table) and one or more PetIDs (from a Pet table). Next I have a search screen where people can multiple select pets from a jquery multiple select dropdown. Let's say somebody selects Dogs and Cats. Now, I want to be able to return all properties that contain BOTH dogs and cats in the many to many table, PropertyPets. I'm trying to do this with Linq to Sql. I've looked at the Contains clause, but it doesn't seem to work for my requirement: var result = properties.Where(p => search.PetType.Contains(p.PropertyPets)); Here, search.PetType is an int[] array of the Id's for Dog and Cat (which were selected in the multiple select drop down). The problem is first, Contains requires a string not an IEnumerable of type PropertyPet. And second, I need to find the properties that have BOTH dogs and cats and not just simply containing one or the other. Thank you for any pointers.

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  • Linq to sql C# updating reference Tables

    - by Laurence Burke
    ok reclarification I am adding a new address and I know the structure as AddressID = PK and all other entities are non nullable. Now on insert of a new row the addrID Pk is autogened and I am wondering if I would have to get that to create a new row in the referencing table or does that automatically get generated also. also I want to be able to repopulate the dropdownlist that lists the current employee's addresses with the newly created address. static uint _curEmpID; protected void btnAdd_Click(object sender, EventArgs e) { if (txtZip.Text != "" && txtAdd1.Text != "" && txtCity.Text != "") { TestDataClassDataContext dc = new TestDataClassDataContext(); Address addr = new Address() { AddressLine1 = txtAdd1.Text, AddressLine2 = txtAdd2.Text, City = txtCity.Text, PostalCode = txtZip.Text, StateProvinceID = Convert.ToInt32(ddlState.SelectedValue) }; dc.Addresses.InsertOnSubmit(addr); lblSuccess.Visible = true; lblErrMsg.Visible = false; dc.SubmitChanges(); // // TODO: add reference from new address to CurEmp Table // SetAddrList(); } else { lblErrMsg.Text = "Invalid Input"; lblErrMsg.Visible = true; } } protected void ddlAddList_SelectedIndexChanged(object sender, EventArgs e) { lblErrMsg.Visible = false; lblSuccess.Visible = false; TestDataClassDataContext dc = new TestDataClassDataContext(); dc.ObjectTrackingEnabled = false; if (ddlAddList.SelectedValue != "-1") { var addr = (from a in dc.Addresses where a.AddressID == Convert.ToInt32(ddlAddList.SelectedValue) select a).FirstOrDefault(); txtAdd1.Text = addr.AddressLine1; txtAdd2.Text = addr.AddressLine2; txtCity.Text = addr.City; txtZip.Text = addr.PostalCode; ddlState.SelectedValue = addr.StateProvinceID.ToString(); btnSubmit.Visible = true; btnAdd.Visible = false; } else { txtAdd1.Text = ""; txtAdd2.Text = ""; txtCity.Text = ""; txtZip.Text = ""; btnAdd.Visible = true; btnSubmit.Visible = false; } } protected void SetAddrList() { TestDataClassDataContext dc = new TestDataClassDataContext(); dc.ObjectTrackingEnabled = false; var addList = from addr in dc.Addresses from eaddr in dc.EmployeeAddresses where eaddr.EmployeeID == _curEmpID && addr.AddressID == eaddr.AddressID select new { AddValue = addr.AddressID, AddText = addr.AddressID, }; ddlAddList.DataSource = addList; ddlAddList.DataValueField = "AddValue"; ddlAddList.DataTextField = "AddText"; ddlAddList.DataBind(); ddlAddList.Items.Add(new ListItem("<Add Address>", "-1")); } OK I am hoping that I did not include too much code. I would really appreciate any other comments about I could otherwise improve this code in any other ways also.

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  • Adding rows with linq trouble with reference table

    - by Laurence Burke
    I am adding a new address and I know the structure as AddressID = PK and all other entities are non nullable. Now on insert of a new row the addrID Pk is autogened and I am wondering if I would have to get that to create a new row in the referencing table EmployeeAddress or does that automatically get generated also. also I want to be able to repopulate the dropdownlist that lists the current employee's addresses with the newly created address. static uint _curEmpID; protected void btnAdd_Click(object sender, EventArgs e) { if (txtZip.Text != "" && txtAdd1.Text != "" && txtCity.Text != "") { TestDataClassDataContext dc = new TestDataClassDataContext(); Address addr = new Address() { AddressLine1 = txtAdd1.Text, AddressLine2 = txtAdd2.Text, City = txtCity.Text, PostalCode = txtZip.Text, StateProvinceID = Convert.ToInt32(ddlState.SelectedValue) }; dc.Addresses.InsertOnSubmit(addr); lblSuccess.Visible = true; lblErrMsg.Visible = false; dc.SubmitChanges(); // // TODO: insert new row in EmployeeAddress to reference CurEmp to newly created address // SetAddrList(); } else { lblErrMsg.Text = "Invalid Input"; lblErrMsg.Visible = true; } } protected void ddlAddList_SelectedIndexChanged(object sender, EventArgs e) { lblErrMsg.Visible = false; lblSuccess.Visible = false; TestDataClassDataContext dc = new TestDataClassDataContext(); dc.ObjectTrackingEnabled = false; if (ddlAddList.SelectedValue != "-1") { var addr = (from a in dc.Addresses where a.AddressID == Convert.ToInt32(ddlAddList.SelectedValue) select a).FirstOrDefault(); txtAdd1.Text = addr.AddressLine1; txtAdd2.Text = addr.AddressLine2; txtCity.Text = addr.City; txtZip.Text = addr.PostalCode; ddlState.SelectedValue = addr.StateProvinceID.ToString(); btnSubmit.Visible = true; btnAdd.Visible = false; } else { txtAdd1.Text = ""; txtAdd2.Text = ""; txtCity.Text = ""; txtZip.Text = ""; btnAdd.Visible = true; btnSubmit.Visible = false; } } protected void SetAddrList() { TestDataClassDataContext dc = new TestDataClassDataContext(); dc.ObjectTrackingEnabled = false; var addList = from addr in dc.Addresses from eaddr in dc.EmployeeAddresses where eaddr.EmployeeID == _curEmpID && addr.AddressID == eaddr.AddressID select new { AddValue = addr.AddressID, AddText = addr.AddressID, }; ddlAddList.DataSource = addList; ddlAddList.DataValueField = "AddValue"; ddlAddList.DataTextField = "AddText"; ddlAddList.DataBind(); ddlAddList.Items.Add(new ListItem("<Add Address>", "-1")); } OK I am hoping that I did not include too much code. I would really appreciate any other comments about I could otherwise improve this code in any other ways also.

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  • Using ADO.NET Entities LINQ Provider to model complex SQL Queries?

    - by Ivan Zlatanov
    What I find really powerful in ADO.NET Entities or LINQ to SQL, is the ability to model complex queries. I really don't need the mappings that Entities or LINQ to SQL are doing for me - I just need the ability to model complex expressions that can be translated into T-SQL. My question is - am I abusing too much? Can I use the Entity Framework for modeling queries and just that? Should I? I know I can write my own custom LINQ to SQL provider, but that is just not possible to handle in the time spans I have. What is the best approach to model complex T-SQL queries? How do you handle conditional group byes, orders, joins, unions etc in the OOP world? Using StringBuilders for this kind of job feels too ugly and harder to maintain given the possibilities we have with Expression Trees. When I use StringBuilder to model a complex SQL Query I feel kind of guilty! I feel the same way as when I have to hard code any number into my code that is different than 0 or 1. Feeling that makes you ask yourself if there is a better and cleaner way of doing it... I must mention that I am using C# 4.0, but I am not specifically looking for an answer in this language, but rather in the domain of CLR 4.

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  • Problem with eager load polymorphic associations using Linq and NHibernate

    - by Voislav
    Is it possible to eagerly load polymorphic association using Linq and NH? For example: Company is base class, Department is inherited from Company, and Company has association Employees to the User (one-to-many) and also association to the Country (many-to-one). Here is mapping part related to inherited class (without User and Country classes): <class name="Company" discriminator-value="Company"> <id name="Id" type="int" unsaved-value="0" access="nosetter.camelcase-underscore"> <generator class="native"></generator> </id> <discriminator column="OrganizationUnit" type="string" length="10" not-null="true"/> <property name="Name" type="string" length="50" not-null="true"/> <many-to-one name="Country" class="Country" column="CountryId" not-null ="false" foreign-key="FK_Company_CountryId" access="field.camelcase-underscore" /> <set name="Departments" inverse="true" lazy="true" access="field.camelcase-underscore"> <key column="DepartmentParentId" not-null="false" foreign-key="FK_Department_DepartmentParentId"></key> <one-to-many class="Department"></one-to-many> </set> <set name="Employees" inverse="true" lazy="true" access="field.camelcase-underscore"> <key column="CompanyId" not-null="false" foreign-key="FK_User_CompanyId"></key> <one-to-many class="User"></one-to-many> </set> <subclass name="Department" extends="Company" discriminator-value="Department"> <many-to-one name="DepartmentParent" class="Company" column="DepartmentParentId" not-null ="false" foreign-key="FK_Department_DepartmentParentId" access="field.camelcase-underscore" /> </subclass> </class> I do not have problem to eagerly load any of the association on the Company: Session.Query<Company>().Where(c => c.Name == "Main Company").Fetch(c => c.Country).Single(); Session.Query<Company>().Where(c => c.Name == "Main Company").FetchMany(c => c.Employees).Single(); Also, I could eagerly load not-polymorphic association on the department: Session.Query<Department>().Where(d => d.Name == "Department 1").Fetch(d => d.DepartmentParent).Single(); But I get NullReferenceException when I try to eagerly load any of the polymorphic association (from the Department): Assert.Throws<NullReferenceException>(() => Session.Query<Department>().Where(d => d.Name == "Department 1").Fetch(d => d.Country).Single()); Assert.Throws<NullReferenceException>(() => Session.Query<Department>().Where(d => d.Name == "Department 1").FetchMany(d => d.Employees).Single()); Am I doing something wrong or this is not supported yet?

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  • Linq to XML Read and output XML generated from lookup list

    - by Greg S
    I am trying to use XML created from a lookup list in SharePoint as a datasource for a treeview. It is in the form of : <NewDataSet> <test_data> <ID>1</ID> <Title>MenuItem_1</Title> <child_of /> </test_data> <test_data> <ID>2</ID> <Title>Subitem_1</Title> <Action>http://www.google.com</Action> <child_of>MenuItem_1</child_of> </test_data> <test_data> <ID>3</ID> <Title>Subitem_2</Title> <Action>http://www.google.com</Action> <child_of>MenuItem_1</child_of> </test_data> <test_data> <ID>4</ID> <Title>MenuItem_2</Title> <child_of /> </test_data> <test_data> <ID>5</ID> <Title>Subitem_2_1</Title> <Action>http://www.google.com</Action> <child_of>MenuItem_2</child_of> </test_data> <test_data> <ID>6</ID> <Title>Subitem_2_2</Title> <Action>http://www.google.com</Action> <child_of>MenuItem_2</child_of> </test_data> <test_data> <ID>7</ID> <Title>Subitem_2_2_1</Title> <Action>http://www.google.com</Action> <child_of>Subitem_2_2</child_of> </test_data> </NewDataSet> There may be N tiers, but the items relate to the parent via the <child_of> element. I can't seem to figure out how to write the LINQ in C# to nest the menu items properly. A friend recommended I post here. Any help is greatly appreciated.

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