private void btnEFDeletingData_Click(object sender, EventArgs e)
{
using (var ctx = new NorthwindsEntities())
{
Categories cat = ctx.Categories.First(c => c.CategoryName == "teste1");
ctx.Categories.Remove(cat);
ctx.SaveChanges();
}
// You can also delete records by using just a few lines of code.
// using (NorthwindsEntities db = new NorthwindsEntities())
// {
// Category category = db.Categories.First(c => c.CategoryName == "Alcohol");
// db.Categories.Remove(category);
// db.SaveChanges();
// }
// In Entity Framework 5.0 you use the Remove method.In previous versions the method was called
// DeleteObject.
}
private void btnEFStoredProcedures_Click(object sender, EventArgs e)
{
using (var ctx = new NorthwindsEntities())
{
var queryFromProcedure = ctx.CustOrderHist("asdasdasd");
foreach (CustOrderHist_Result res in queryFromProcedure)
{
Debug.WriteLine(string.Format("Product Name; {0}", res.ProductName));
}
}
// Call a Stored Procedure
// As previously shown, all the stored procedures were created as methods in the NorthwindsEntities
// class by the Entity Data Model Wizard.To call a stored procedure, you simply need to call the method.
// The following code sample calls the CustOrderHist stored procedure, passes in a customer ID, and
// then prints the orders to the Output window:
// using (NorthwindsEntities db = new NorthwindsEntities())
// {
// var custOrderHist = db.CustOrderHist("ALFKI");
// foreach (CustOrderHist_Result result in custOrderHist)
// {
// Debug.WriteLine(string.Format("ProductName: {0}, Total: {1}",
// result.ProductName, result.Total));
// }
// }
// As you can see, all the heavy lifting is done for you by the Entity Framework, but it is still important to
// understand what is going on behind the scenes with ADO.NET to become a more complete developer.
}
private void btnEFUpdatingData_Click(object sender, EventArgs e)
{
using (var ctx = new NorthwindsEntities())
{
Categories cat = ctx.Categories.First(c => c.CategoryName == "Produce");
cat.Description = "Dried fruit and bean curd - modified";
ctx.SaveChanges();
}
// Updating records is just as trivial.The following code sample retrieves the Category with the name
// Alcohol, changes its description, and then updates the record in the database:
//Category category = db.Categories.First(c => c.CategoryName == "Alcohol");
// category.Description = "Happy People";
// db.SaveChanges();
}
private void btnEFInsertingData_Click(object sender, EventArgs e)
{
using (var ctx = new NorthwindsEntities())
{
Categories cat = new Categories();
cat.CategoryName = "teste1";
cat.Description = "Test Description";
//
ctx.Categories.Add(cat);
ctx.SaveChanges();
//
// This code created an instance of the Category class and initialized its properties. It then added
// the object to the Categories property of the NorthwindsEntities.The SaveChanges() method
// is then called to add the record to the database. Again, there was no SQL syntax needed; the Entity
// Framework handled all that behind the scenes.
}
}
private void EF_Tips_Selecting_Data_From_Db_Using_Linq_Joining()
{
using (var ctx = new NorthwindsEntities())
{
var products =
from
c in ctx.Categories
join
p in ctx.Products on c.CategoryID equals p.CategoryID
select p;
foreach (Products prod in products)
{
Debug.WriteLine(string.Format("ProductName: {0}", prod.ProductName));
}
}
}
private void EF_Tips_Selecting_Data_From_Db_Using_Linq()
{
using (var ctx = new NorthwindsEntities())
{
var categories = from c in ctx.Categories select c;
foreach (var cat in categories)
{
Debug.WriteLine(string.Format("Id d acategoria: {0}", cat.CategoryID.ToString()));
}
}
}
private void EF_Tips_Selecting_Data_From_Db_Using_ToList()
{
using (var ctx = new NorthwindsEntities())
{
var categories = ctx.Categories.ToList();
foreach (Categories cat in categories)
{
Debug.WriteLine(cat);
}
}
}