ASP.Net MVC cannt create controller for sql server db

Question

i find the problem when i tried to create a controller for sql server table,not code-first(localdb),and i check the connectionString ,but i think i hasn't mistakes on it

for safety ,i hide the machine-name,username and password

One or more validation errors were detected during model generation:

DB2Ex.Model.Student: : EntityType 'Student' has no key defined. Define the key for this EntityType.

Students: : EntityType 'Students' has no key defined. Define the key for this EntityType.

public class Student
{
    public int xh { get; set; }
    public string xm { get; set; }
    public string xb { get; set; }
    public string csrq { get; set; }
    public string jg { get; set; }
    public string sjhm { get; set; }
    public string yxh { get; set; }
    public string mm { get; set; }
}
public class StudentDBContext : DbContext
{
    public StudentDBContext()
        : base("schoolDB")
    {
    }
    public DbSet<Student> Students { get; set; }
}

<add name="schoolDB" connectionString="Data Source=DESKTOP-*****;Initial Catalog=school;Persist Security Info=True;User ID=***;Password=***" providerName="System.Data.SqlClient" />

Answer 1

Assuming xh is the key field in the database, you need to define it in your Student model too:

public class Student
{
    [Key]
    public int xh { get; set; }
    public string xm { get; set; }
    public string xb { get; set; }
    public string csrq { get; set; }
    public string jg { get; set; }
    public string sjhm { get; set; }
    public string yxh { get; set; }
    public string mm { get; set; }
}

Answer 2

I find the way to solve it

-Models
-Create a "ADO.Net Model"
-Choose the sql server db
-Dont forget choose "create the default connectionstring"

Then create a controller for the db.tables and the Dbcontext that hava been created by VS

And i will get the similar views like choosing the code-first way:create new,details,delete and other options