Set decimal(16, 3) for a column in Code First Approach in EF4.3 [duplicate]

The DataType Attribute is a Validation Attribute. You need to do that using the ModelBuilder. public class MyContext : DbContext { public DbSet<MyClass> MyClass; protected override void OnModelCreating(DbModelBuilder modelBuilder) { modelBuilder.Entity<MyClass>().Property(x => x.SnachCount).HasPrecision(16, 3); modelBuilder.Entity<MyClass>().Property(x => x.MinimumStock).HasPrecision(16, 3); modelBuilder.Entity<MyClass>().Property(x => x.MaximumStock).HasPrecision(16, 3); } }