Simple Example of ADO. NET Entity Framework and Code First, ado. netentity

Simple Example of ADO. NET Entity Framework and Code First, ado. netentity

1. Install EntityFramework;

Open NuGet in vs and enter Install-Package EntityFramework in the command line.

Ii. Basic usage

1. Create a data model

Class Student {public int id {get; set ;}// ID public string name {get; set ;}// name public byte age {get; set ;}// age}

2. Create a data context

Using System. data. entity; // reference Entity Frameworknamespace SQL {class StudentContext: DbContext {public StudentContext (): base (@ "Data Source = MYPC \ MSSQLSERVER; Initial Catalog = entitycodefirst; User ID = sa; password = 123456 ") {} public DbSet <Student> Students {get; set ;}}}

3. Use

Using System; namespace SQL {class Program {static void Main (string [] args) {// save using (var data = new StudentContext () {var student1 = data. students. create (); // Create a student's object student1.name = "Tom"; student1.age = 15; data. students. add (student1); // Add the student object to the student table var student2 = data. students. create (); student2.name = "Xiaohong"; student2.age = 15; data. students. add (student2); data. saveChanges (); // save it to the database} // read using (var data = new StudentContext () {foreach (var item in data. students) {Console. writeLine ("ID: {0}, name: {1}, age: {2}", item. id, item. name, item. age) ;}} Console. readKey (true );}}}