WISE OWL EXERCISES
VISUAL C# EXERCISES
- Creating forms (4)
- Coding form events (1)
- Laying out your code (2)
- C# variables (4)
- Enumerations and constants (2)
- Conditions (2)
- Modular code (3)
- Arrays (2)
- Looping (2)
- Files and folders (3)
- Properties in C# (3)
- Using lists (3)
- Validating forms (6)
- Toolbars, menus and status bars (1)
- FileDialogs and StreamReaders (1)
- Debugging and trapping errors (1)
- Introduction to DataGridViews (1)
- DataGridView events (3)
- Complex DataGridViews (2)
- Creating classes (2)
- The form as a class (1)
- Data structures (4)
- Inheritance (4)
- Interfaces (2)
- Delegates and events (2)
- Writing LINQ (1)
- Advanced LINQ (3)
- LINQ to SQL models (1)
- Writing LINQ to SQL (2)
- Grouping using LINQ (2)
Visual C# | LINQ to SQL models exercise | Use LINQ to SQL to list authors and their count of books
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If you haven't already done so, go into SQL Server Management Studio and open the file in the above folder and run its script. This should generate a Books database.
Add a new LINQ to SQL classes item called Books to your project:
The item that you should add to your project.
In Server Explorer, create a connection to this database:
You should be able to expand the tables to show the tblAuthor and tblBook tables.
Drag these two tables onto your O/R designer window, and rename the tables to get this:
We've renamed the entities, but left all of the properties the same.
Create a new window called frmBooks, and within this create code to list out the authors. This should use the data context that you've created:
// use the classes in the LINQ to SQL data model
using (BooksDataContext books = new BooksDataContext())
Now use LINQ to SQL to list out all authors with the number of books they've written. The easiest way to do this is probably to create a new anonymous type with two properties:
- AuthorName - the first name and last name concatenated (with a space in between)
- BookCount - the number of books written by the author
This is what you should see accumulated when you run your code:
For each author you should see in parentheses the number of books they've written.
At this point you should be marvelling at how easy LINQ to SQL is to code!