Updating records using linq sda dating singles
If the table object was null, the I set the Update flag to false.The accept button will have code to direct the appropriate call like this: The Database Commands methods are located in my cs file as this is a good place to put my general code (personal preference). If there is an SQL error of some sort, the program will open a messagebox and explain the error.Finally, six months later, I found someone who agreed that this was a problem and created his own solution.Paul Welter of Lore created a library called Entity Framework.NET using some additional code which will be included in this article.For purposes of this article I will assume you have a basic working knowledge of LINQ, LINQ to SQL, or LINQ to Entities. I really, really struggled to find a similiar link for VB Look at that link and maybe you'll see something in your own code that might fix things.
I get the record using the query: Dim values = From n In entities. Looks like, update Model is working, but since I am not updating anything, there is no change in the DB.The following method marks a single product as discontinued, based on the product ID: As you can see, I’m using a simple LINQ query to get a single product with a Product ID matching the product ID parameter of the method, setting the Discontinued flag, and saving the changes. Let’s say I wanted to discontinue all products which are out of stock and have no units on order, instead of just one.The overhead of this is a little bit more than if I were using ADO. In this case I have to execute one database call to retrieve the product, and one database call to update the data. Using only the built-in Entity Framework functionality, I would have to do something like this: This LOOKS pretty simple – I’m iterating through the context. Behind the scenes, Entity Framework is executing one SQL ‘select’ call to retrieve all the products, but when you call Save Changes, it is executing one SQL ‘update’ call .According to MSDN, “Entity Framework (EF) is an object-relational mapper that enables .
NET developers to work with relational data using domain-specific objects.” Essentially, it is a layer between your application code and your database which maps your C# classes to database tables. = null) //here logic of what should happend if there is something in db else Here if I make similar checks for updating records ?