Map model to existing database table using Entity Framework

Question

I face some difficulties when attempt to map my class to existing table using Entity Framework. I currently using Code first but a table was created without it and i cannot map it to a model a created.

My class:

 [Table("AgentCallsByPartner")]
public class AgentCallsByPartnerModel
{
    [Key]
    public int AgentCallID { get; set; }

    [Required]
    public DateTime CallDate { get; set; }

    public string CustomerID { get; set; }

    public string AgentNo { get; set; }

    public string AccountCreated { get; set; }

    public string QuoteStarted { get; set; }

    [Required]
    public string GroupName { get; set; }

    [Required]
    public string GroupRollup { get; set; }

}

Context

    public DbSet<AgentCallsByPartnerModel> AgentCallsByPartner { get; set; }

And this is my table

But when I try to get users from the database, I get an exception

DbContext has changed since the database was created....

So what is my mistake? Thanks

did you update your migration ? did you apply drop create new database if mode change ? — Nazmul Hasan
– Nazmul Hasan, Commented May 5, 2016 at 17:46
i did not since table was created directly in sql server, do i need to do something? — Gilberto Quintero
– Gilberto Quintero, Commented May 5, 2016 at 17:47

Community · Accepted Answer · 2020-06-20 09:12:55Z

2

you can be perform several way i just describe few way

From the Tools menu, click Library Package Manager and then Package Manager Console.

The enable-migrations command creates a Migrations folder in the your project, and it puts in that folder a Configuration.cs file that you can edit to configure Migrations.

(If you missed the step above that directs you to change the database name, Migrations will find the existing database and automatically do the add-migration command. That's OK, it just means you won't run a test of the migrations code before you deploy the database. Later when you run the update-database command nothing will happen because the database will already exist.)

more detail migration http://www.codeproject.com/Articles/801545/Code-First-Migrations-With-Entity-Framework

another way :

How to recreate database in EF if my model changes?

Note: if you use migration then do not lose data value most of time

Update:

problem in migration process run the flowing command

Add-Migration Initial -IgnoreChanges

Update-Database -verbose

edited Jun 20, 2020 at 9:12

CommunityBot

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answered May 5, 2016 at 17:52

Nazmul Hasan

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2 Comments

Gilberto Quintero Over a year ago

I ran the add-migration command, them update-databse, it throw a message in red saying There is already an object named 'AgentCallsByPartner' in the database.

Nazmul Hasan Over a year ago

try with this blog ... codeproject.com/Articles/801545/…

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