DbContext APIs (for Insert, Update, Delete and Get)

The model of SalesOrder.edmx

SalesOrder.Context.cs

SalesOrderDBContext : DbContext

 

GetCustomers()

Context.Entity.ToList()

 

GetCustomer(int id)

Context.Entity.Find(primary_key)

TOP (2): to make sure Find() is always return 1 record, so it will raise an exception if SQL server return 2 records

 

InsertCustomer()

1. Context.Entity.Add(item)

2. Context.SaveChanges()

3. Able to get primary key after insertion

INSERT and SELECT are in a single transaction

1. For context.CustomerSet.Add(customer);

2. For customer.Id

 

UpdateCustomer()

SELECT and UPDATE are in different transactions

Hardcode name for WHERE condition

 

DeleteCustomers()

Context.Entity.Remove(item)

SELECT and DELETE are in different transactions