Question

Say I have a table called Users, which contains your typical information: Id, Name, Street, City–much like in the example here:

http://weblogs.asp.net/manavi/archive/2010/12/11/entity-association-mapping-with-code-first-part-1-one-to-one-associations.aspx.

Among other things, this article states:

“Code First has a concept of Complex Type Discovery that works based on a set of Conventions. The convention is that if Code First discovers a class where a primary key cannot be inferred, and no primary key is registered through Data Annotations or the fluent API, then the type will be automatically registered as a complex type. Complex type detection also requires that the type does not have properties that reference entity types (i.e. all the properties must be scalar types) and is not referenced from a collection property on another type.” My Address class meets these criteria: it’s made up of strings and isn’t used anywhere else.

In the app, though (I’m not sure if this makes any difference), we’re calling the Users something else–say, Techs. I want to break out User’s address columns into an Address so each Tech can have its own Address. According to the article above, EF should infer this and take care of the complex type automatically. What I’m getting,though, when the context attempts to give me a Tech, is the following exception:

System.Data.EntityCommandExecutionException: An error occurred while executing t
he command definition. See the inner exception for details. ---> System.Data.Sql
Client.SqlException: Invalid column name 'Address_Street'.
Invalid column name 'Address_City'.
Invalid column name 'Address_State'.
Invalid column name 'Address_Zip'.

It looks like it’s trying to make sense of the Tech.Address property, but is giving each of its sub-properties the wrong name (e.g., “Address_City” instead of “City”).

Any ideas on how I can rectify this?

Answer 1

That is correct behavior. Default convention always prefixes properties mapped to complex type with type name. If you want to use different column names you must map them either through data annotations:

public class Address
{
    [Column("City")]
    public string City { get; set; }
    ...
}

or through fluent API:

modelBuilder.ComplexType<Address>().Property(a => a.City).HasColumnName("City");