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); } } }