Entity Framework Learning One: Creating a new database on a. NET class basis

This article reads Code-first develoment with the Entity Framework for simple notes.

1. First we create a person class

 Public class person    {        publicintgetset;}          Public string Get Set ; }          Public string Get Set ; }    }

Then create the context class, which inherits from the DbContext class

 Public class Context:dbcontext    {        publicbase("ConnectionString")        {        }          Public Get Set ; }    }

Note that base ("ConnectionString") needs to configure the link string, otherwise EF will use the default connection settings.

< connectionStrings > <  name= "ConnectionString"ConnectionString= "Data source=192.168.0.14; Initial Catalog=efsample;user id=sa;password= "providerName=" System.Data.SqlClient "  /></connectionStrings>

Using the code below, if the database does not exist, the data is created in the data

Static voidMain (string[] args) {            using(varcontext=NewContext ()) {               BOOLtemp=context.                Database.createifnotexists (); if(temp) {Console.WriteLine ("Create success!"); }                Else{Console.WriteLine ("creation failed!");        }} console.readkey (); }

After running this code you will find that you have created a database named "Efsample" in the database, which is the name of the database that you just set the connection string to in the configuration file.

2. Add a record to the database we created

classProgram {Static voidMain (string[] args) {            using(varcontext=NewContext ()) {               BOOLtemp=context.                Database.createifnotexists (); varperson =NewPerson {FirstName="John", LastName="Doe"                }; Context.                People.add (person); Context.            SaveChanges ();        } console.readkey (); }    }

Using this code will find that the people table is created in the database and adds a record that EF automatically determines whether there is a people table in the database (the table name is based on the public dbset<person> people {get) defined in the context class; Set } property name). We can also map the tables we've created, which we'll cover later. In this code you find that we do not assign a value to PersonID, and EF automatically sets the +id name to the table primary key.

Entity Framework Learning One: Creating a new database on a. NET class basis