Use Of .Include To Select From An Association Table Which Is Replaced By Navigation Properties
Jul 14, 2011
In my database I have 3 tables Act, ActVisi and Visi. Table ActVisi is an association table between Act and Visi tables. In My EF4 data model the association table ActVisi is replaced by a many to many navigation property in both Acts and Visis entities.I want to select the entries whose Visicode=1 (in the ActVisi association table). I have tried the query below and it works when I remove Include("Visis").Where(Function e.Code = 1) but I am getting all the results. How can I make the below query work. I suspect that my lambda syntax in vb is incorrect.
EF Navigation properties don't raise OnPropertyChanging and OnPropertyChanged Events.When looking into the entity framework auto-generated code a simple property will have a setter that looks like this:
Set OnNameChanging(value) ReportPropertyChanging("Name")[code]......
Seems like the navigation properties should call just call the 4 change notification methods. Do you have any insights on why the EF generater would be implemented in this manner? Is there an option somewhere to turn on notification or a work-around? Also, I assume that editing the designer generated code is bad practice, correct?
I am trying to build a class that includes an array so that I can refer to each element in the array. For example, let's presume I'm building a class that includes student id, student name, and then an array of 8 courses (numbered 0-7). I'd like to be able to refer to:
baseClassName.Course(0) baseClassName.Course(1)
etc...but I know that's NOT how it's done...but how IS it done?
Microsoft VB Grade Book. A teacher maintains a database containing two tables-student and grades. The students table has three fields: studentID, lastName, and firstName. The Grades table has four fields: studentID, firstExam, secondExam, and finalExam. At the beginning of the semester, the Students table is filled in completely with a record for each student in a class, and the Grades table has a record for each student that contains only the student's ID number. (Note: The database is contained in the file Gradebook.accdb from the folder CH10Databases.) Write a program that allows the instructor to record and process the grades for the semester. The program should do the following:
A) Use a navigation toolbar to fill the Grades table.
B) After all the grades have been entered, display a DataGridView control showing the name of each student and his or her semester average. The semester average should be calculated as (firstExam + secondExam + 2*finalExam)/4.
where m_handsets is defined as Private m_handsets As IQueryable(Of RL.tblTelephoneNumbers)
which works as expected however what I want to do know is query the Navigation property (tblCalls) so I can do something like the following From p In m_handsets.tblCalls Where m_handsets.tblCalls.price > 100
I think the complexity comes here because in this instance I could have 5 tblTelephoneNumbers in m_handsets and then x amount of calls for that particular telephone number. I am interested in the tblCalls for each but I would like to filter them all for each tblTelehoneNumber.
Entity Diagram which (hopefully) should illustrate further So I currently know all the handsets that are associated with the company I am interested in. I can also see the calls loaded as a navigation property in debug mode, but I want to say is take this filter (in this example price>100 and apply it to all handsets->calls
I have two tables Products and Categories with a many to many relationship. I am trying to copy the categories linked to one product (OriginalProduct) to another product (newProduct). The problem is when I execute the SaveChanges() method, I not only get the records in my linking table, but it also creates another copy of the categories in the categories table. I've tried this in many ways but here are the last couple that I've attempted:
' Copy Product/Categories For Each oneProdCategory In OriginalProduct.Categories Dim relatedCategory = _productContext.GetObjectByKey(New EntityKey ("ProductInfoEntities.Categories", "RecordId", oneProdCategory.RecordId))
I have two tables Employees and CafeLogs. Some employees can be cashiers and also customers at the Cafe shop.
Table structures:
Employees: EmployeeId(PK) , FirstName, LastName CafeLogs: LogId (PK), CashierId, EmployeeId, Value, => CashierId and EmployeeId are the data from column EmployeeId of Empoyee table
Table relationship:
Employees 1:N CafeLogs (CashierId (FK))
[code]....
Right now I know how to select only LogId, Employee's name, and , Value, not with Cashier name yet.
Dim query = From log In db.CafeLogs _ Join emp In db.Employees On emp.EmployeeId Equals log.EmployeeId _ Select log.LogId, emp.FirsName, emp.LastName, log.Value
Is it possible using Linq to select the FirstName and LastName out of all the Bloops in the collection of Bloops and return a collection of Razzies? Or am i limited to a For-Loop to do my work?
To clear up any confusion, either VB or C# will do. Also this will probably lead to me asking the question of (What about using a "Where" clause).
what I could use to display some help for a function (or subroutine) in the popup that appears when entering said function in the VS2005 IDE when using VB.NET. I discovered later that you could use the XML code documentation to write the description. Just type 3 single quotes (''') on a new line directly above the function you want to document and press return. The IDE creates a comment template. Just enter your description text within <para></para> in the <summary> section and it will show up when the intellisense dropdown is displayed for your function.
i want to create a table that include a current year data and as well as previous data to be compare. here is the example of the table that i want to create: but i want to compare one of the annual data with the previous year. as example i want to compare between the data of current AR of 2007 with the current AR for 2006, Current AR of 2006 with current AR for 2005 and go on~, but i have no idea how to do it.
I'm Using resharper 6 nighty builds and VB.net. I've a big medium project with multiple files that don't follow the code style conventions of my company.I've configured resharper with my own convenctions and It suggest to me the right name for each variable (perfect!).But I can't find any automagic way to make the current name to be replaced with the suggested name.
I am looking for some code that will allow me to set field properties of fields in a table I have just created in code using vb.net (2005). I have seen a number of articles to do this in vb6 but not vb.net.
I have a class that represents the table of a db-row. Its properties are the columns of the table. I add a new row to the table with the following code:
Public Sub AddRow(oTestRow As TestRow) Dim sql As String With oTestRow
[Code]....
That is just an example, but my classes have around 30-40 properties and this brings a very large and complex sql string. Creating, editing or maintaining these sql strings for many classes could generate errors. I am wondering if any compact way or method exists in order to add the whole object's istance (the properties of course) to the table "TestTable" without writing such a large sql string. I created the TestRow in the way that its properties are exactly the columns of the table "TestTable" (with the same name). But I did not found in the ADO.NET anything that could be used.
I have a form which is bound to a table that includes information about properties (real estate). Each property can have a number of inspections. These inspections are included in a separate table.
I want to use the form to show the property information and a data repeater to show all the inspections for that property.I can't seem to get the data repeater to bind to the inspection table and pull only those records related to the property information table. In fact, the data repeater shows nothing.
I can get a data repeater to show all the records in the inspection table when I put the control on its own form, for testing purposes.
I have a need to populate a data object containing 30+ properties from a database table. I could create a simple class containing a public variable for each of the required properties, but I don't want to.
Is the following code a bad idea:
<Serializable()> Public Class DtoEmployee Public EmployeeId As String
in a windows form if i want to duplicate the properties window layout on my form, which is basically a 2 column table with title on the left and value on the right, what control do i use to achieve that?
I've created a class that inherits from CollectionBase that populates with a custom object type. I populate the custom collection and set it as the datasource for a ListBox control and set the appropriate DisplayMember value to one of the properties of my custom object.
While the binding behaviour is working great, I'm trying to polish up the UI because when the list of objects is somewhat long, there is a momentary flash where the ListBox displays the custom classname which is then replaced with the appropriate display data. I'd like to keep that initial flash of the ToString() method from appearing. I tried SuspendLayout() and ResumeLayout() on the control and the form, but neither keeps the flash from occuring.
I want to create a class (I think) that has properties that correspond to column names in a database table, such that they come up in Intellisense when I type the dot after the class name. Is this possible to do?
Below is an snippet from my project template. I have some classes I want to link to in the project.One of my developers created the template and I copied it to my PC.It seems to work on his, but when I create a new project, instead of keeping the hard coded path the "my documents" gets replaced.I know this is a little cryptic, but I was hoping to flesh the question out with your questions.[code]
I have a table in a sql database and in this table i have a column at the end, that is creating an automating date and time everytime when new record is inserted. I want to select from an application in VB al the records in wich the date and time there where inserted is bigger than one variable that I created on runtime.For example I need to see all the records that were inserted later than 10, august, 2010 13:45:10 How can I do that?
I have code that downloads a webpage into an .html or a .txt file so I have the webpage source code, how do I:Search the HTML source code in the file for a keyword anchor point (Hair Color, it's unique in the entire webpage source code)Step down 3 linesAssign what ever is on that line to a variable called FoundIt?
i have a table with username, password and email columns.now i have textbox with name emailtxt, i want to see username, on label.when i put an email, then it will select its corrospondese username, so that the username will be shown on label
Protected Sub cmdShow_Click(ByVal sender As Object, ByVal e As System.EventArgs) dim con as sqlconnection dim str as string con = New SqlConnection("server=(local); Data Source=gig;Initial Catalog=myd;User ID=sa;Password=test") str="select username from mytable where email=' "& emailtxt.text & " ' " con.open()
what sql command i must use. this is my current command but it give me an error saying "The specified filed 'ClientNo' could refer to more than one table listed in the FROM clause of your sql statemate." [code]
I want to select a table on my database but I have the name of the table on a variable.Because I will create tables periodically I have don't know the name of the future tables so I will stored on a variable. The problem is how I call the variable on SQL statment. I made a code using the addwithvalue to use the variable on the SQL but didn't work. Here is my code
Dim tablename As String tablename = InputBox("Enter the table name") Dim myconecction As String
