CODEWITHSUNDEEP
c#entity-framework-core
alex
alex

Reputation: 25

Entity Framework core doesn't save changes (no primary key, one row table)

I have a legacy database with the table which has only one row without a primary key. When I try to update this row nothing happens. I searched a lot and came on this line of code (dbf.Entry(nextPro).State = EntityState.Modified;). When I added this code I got the error: "Unable to track an instance of type 'NxtId' because it does not have a primary key. Only entity types with primary keys may be tracked."

I cannot remove the row and add a new one. I cannot add primary key. I have the only option to update the row somehow.

var nextPro = dbf.NxtId.FirstOrDefault();

nextPro.ProductNo = 239071;
dbf.Entry(nextPro).State = EntityState.Modified;
dbf.SaveChanges();

Entity:

public partial class NxtId
{
    public int? ProductNo { get; set; }
    public int? Uid { get; set; }
    [Key]
    public int? SatCode { get; set; }
}

Upvotes: 0

Views: 2167

Answers (2)

alex
alex

Reputation: 25

The code that works for me (Entity Framework Core doesn't like to work with raw sql). So I had to find a command that still works.

        using (SqlConnection connection = new SqlConnection(Configuration["ConnectionStrings:Test"]))
        {
            SqlCommand command = new SqlCommand("UPDATE dbo.NxtID SET ProductNo =" + newProductNo, connection);
            command.Connection.Open();
            command.ExecuteNonQuery();
        }

Upvotes: 1

Progman
Progman

Reputation: 19570

You cannot track or change an entity with Entity Framework when it does not have a key. However, you can still read data from the database. Also, you can run custom manually written SQL queries using the extension method RelationalDatabaseFacadeExtensions.ExecuteSqlRaw(). Use it to send a normal UPDATE query and then read the entity again from the database to get the new values.

dbf.Database.ExecuteSqlRaw($"UPDATE {nameof(NxtId)} SET {nameof(NxtId.ProductNo)} = {{0}}", 239071);
var nextPro = dbf.NxtId.Single();

Upvotes: 2

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