Question
Using EntityFramework code-first, I've created a simple Foo table. Here's my entity:
public class Foo
{
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public virtual string Id { get; set; }
public virtual string Name { get; set; }
}
However whenever I try to insert a new row, I get a Cannot insert the value NULL into column 'Id'. Why is this happening when I've added a DatabaseGenerated attribute? Deleting and recreating my table makes no difference.
Accepted Answer
Identities for string column types are not supported with SQL Server. (How do you expect such a string to look like?) To get this working you could - for example - add a computed column/user defined function in SQL Server that formats a string from an ordinary int identity column - as shown here.
Popular Answer
- you forgot the
Keyattribute. and there is no need to usevirtualfor primary key. - as mentioned by Slauma you can't use
Identityfor string datatype.
Try this code:
public class Foo
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int Id { get; set; }
public virtual string Name { get; set; }
}
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