After EF Core is configured, you can use it to perform CRUD operations on your entity classes. Then, you can develop against C# classes, delegating the database operations to the context class. Database providers in turn translate it to database-specific query language. An example is SQL for a relational database. Queries are always executed against the database, even if the entities returned in the result already exist in the context.
Query data
The context object exposes a collection class for each entity type. In the preceding example, the context class exposes a collection of Pizza objects as Pizzas. Given that we have an instance of the context class, you can query the database for all pizzas:
C#Copy
var pizzas = await db.Pizzas.ToListAsync();
Insert data
You can use the same context object to insert a new pizza:
C#Copy
await db.pizzas.AddAsync(
new Pizza { ID = 1, Name = "Pepperoni", Description = "The classic pepperoni pizza" });
Delete data
Delete operations are simple. They require only an ID of the item to be deleted:
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var pizza = await db.pizzas.FindAsync(id);
if (pizza is null)
{
//Handle error
}
db.pizzas.Remove(pizza);
Update data
Similarly, you can update an existing pizza:
C#Copy
int id = 1;
var updatepizza = new Pizza { Name = "Pineapple", Description = "Ummmm?" };
var pizza = await db.pizzas.FindAsync(id);
if (pizza is null)
{
//Handle error
}
pizza.Description = updatepizza.Description;
pizza.Name = updatepizza.Name;
await db.SaveChangesAsync();nutanix certification malaysia
