ADO.NET :: Linq Getting Data From Field On Record?
Aug 24, 2010
I would assume this is possiable but I cannot seem to find it anywhere. I just one the contents of a single field, I don't see why I have to return the how
record to get get that information, here is my current code, how can I make this better without returning the entire record, for just getting contents of one field.
Above is the beginning of a ListView and its LinqDataSource. When the HTML displays, it picks up only the first record in the table but it's supposed to show a profile page for the user who is signed in (UserID == @UserID).
I wanted to list the bonuses in a gridview, so i made a query to return list of bonus records and my data access object returns the result set as Bonus business object ( generic collections of bonus BO ). i have bind my gridview with the bonus collection.
now my problem is that collection has the property "EmployeeID" and it will be displayed but instead of showing EmployeeID, i wanted to show Employee Name in that grid. I have a gridview where i want to list the bonus records ( bonus ID, bonus date, bonus description, employee ID) ,
I have a form that contains a text box called "MyDate" in which the user enters a date. I have a table that contains records of which one of the fields in the record is a date field named "DateAvailable" (type is "datetime"). I want to compare the data in the text box to the "DateAvailable" field in record. How do I define my text box as a "datetime" field.
I have a listview that has been constructed using tables. I have set the DataKeyNames="SomeTextField" among others. This column is currently not visible in the ListView.
I'd like to populate a textbox on the click of any listview record with the contents "SomeTextField" column.
I'm inserting data into a database with Linq to SQL and would like to access the primary key of that record WITHOUT doing a query for the values I've already captured.
Here is my insert startment:
[Code]....
There is a value in the table that is an auto increment integer.
Rather than doing a query for the pagetitle, description and content I'd like to just access the primary key that I would have just generated by performing the insert.
Is this possible or would I have to perform the query as I've just mentioned to retrieve it?
If I have an ID, I would like to retrieve the next item that also has the same category as the item ID I have. So, for example, if I have ID=2, I would like to return the item with ID=4 (as item ID=3 has a different category).
how to pull a RANDOM item from the database when using LINQ. There seems to be a couple of differnet ways to handle this. What I need to do though is pull a RANDOM item from the database that the user has not seen before.
The data I am pulling from the database is very small. Is there any way I can just hit the database once for 1000 records and then randomly scroll through those?
Should I put a cookie on the users system recording the IDs of which items they have seen, pull a random record, check to see if it is seen and if so, pull from the database again? That seems like performance issues just waiting to happen.
I use the following code to insert recode to a sql 2008 table, the field ID of DBProgram is IDENTITY, so SQL 2008 SERVER will pass a value to it automatically. How can I get the ID value of the record I just insert ?
DBProgram dbProgram = new DBProgram(); db.DBPrograms.InsertOnSubmit(dbProgram); db.SubmitChanges();
Unable to cast object of type 'System.Data.Linq.DataQuery`1[Username]' to type 'Username'.
I've been searching but can't find a solution. This particular table has 4 columns. The first column is the int indentifier. Column 2 is "username" (varchar50) and is the primary key. Column3 is "userID" (uniqueidentifier) and column 4 is "active" (varchar5)
I am writing an application in C# that uses LINQ to validate a datacontext off a textbox to see if the record exists already. If the record does exist I inserted an if statement to advise the user that the record exists, if the record does not exist I would like to allow the record to be added to the database. If I take out my else statement everything works fine as far as inserting goes, but I do not want to allow inserts in this scenario. I have tried moving the if and else statement to different parts of the code but can't quite figure this one out.
in my asp.net application. I want to insert the student registration entry through my web form. but want to use proper object oriented method. like by create the object as "Student" it will have required property. and want to insert new node with incremental (auto increment) Student ID. I am using c#. how can i achieve this? will Linq is best way to do this?
is there any way I can retrieve the identity value (auto generated primary key value), of a column after inserting a new database record using linq to sql? i could i achieve this like this using stored procedure: //***insert some recor*** return @@identity. how do I achieve thesame with linq to sql
I am trying to delete record from table with proper mapping from linq to sql.There is an error stating that Rmove method not found and are u missing an assembly reference.
AdventureWorks db = new AdventureWorks("Integrated Security=sspi"); var query = from con in db.Contact where con.LastName == "Klein" select con; foreach (Contact del in query) { db.Contact.Remove(del);//???Remove not working } db.SubmitChanges(); textBox1.Text = "Contact deleted.";
Dim newMem As New Subscription With { _ .First = txtName.Text, _ .Email = txtEmail.Text, _ .dateLastEmail = "1/1/1980", _ .subDate = Now} dbp.Subscriptions.InsertOnSubmit(newMem) dbp.SubmitChanges()
The table contains a field called conDate that is nullable, and in this case I want it to remain null. It will get a date value later, when a confirmation is received. If I add .conDate = "1/1/1980", _ I can successfully add the record, but without that line I get System.InvalidOperationException: Nullable object must have a value. I tried this:
Dim DateConfirm As System.Nullable(Of DateTime) = Nothing and adding .conDate = DateConfirm, _ but that didn't help either. How can I add a record without giving a date to a field I want to remain null?
