Entity Framework DataAnnotations Cheat Sheet

I have been looking everywhere for a Cheat Sheet like this but could not find anything, So I had to make my own, I hope you find it useful:

DataAnnotations Cheat Sheet v1.0

Name: AssociationAttribute
Description: Specifies that an entity member represents a data relationship, such as a foreign key relationship.
Usage: [Association(Name, OtherKey, ThisKey)]
Example:

[Table(Name = "Customers")]
public partial class Customer
{
    [Column(IsPrimaryKey = true)]
    public string CustomerID;
    // ...
    private EntitySet<Order> _Orders;
    [Association(Storage = "_Orders", OtherKey = "CustomerID")]
    public EntitySet<Order> Orders
    {
        get { return this._Orders; }
        set { this._Orders.Assign(value); }
    }
}

Name: BindableTypeAttribute
Description: Specifies whether a type is typically used for binding.
Usage: [BindableType(IsBindable = bool)]
Example:

  [BindableType(IsBindable = false)]
  public enum EntityState
  {
    Detached = 1,
    Unchanged = 2,
    Added = 4,
    Deleted = 8,
    Modified = 16,
  }

Name: CompareAttribute
Description: Provides an attribute that compares two properties.
Usage: [Compare(OtherProperty)]
Example:

public class Visitor
{
    public string EmailAddress { get; set; }
    [Compare("EmailAddress", ErrorMessage="Email Addresses Do Not Match." )]
    public string ConfirmEmailAddress { get; set; }
}

Name: ConcurrencyCheckAttribute
Description: Specifies that a property participates in optimistic concurrency checks. ConcurrencyCheckAttribute is used to specify that a property/column has a concurrency mode of “fixed” in the EDM model. A fixed concurrency mode means that this property is part of the concurrency check of the entity during save operations and applies to scalar properties only.
Usage: [ConcurrencyCheckAttribute]
Example:

  public class  Book
    {
        public long BookId { get; set; }
        public virtual string Title { get; set; }
        public Author Author { get; set; }
        [ConcurrencyCheckAttribute]
        [TimestampAttribute]
        public byte[] TimeStamp { get; set; }
    }

Name: CreditCardAttribute
Description: Specifies that a data field value is a credit card number.
Usage: [CreditCardAttribute]
Example:

public class Buyer
{
    public string Nombre { get; set; }
    [CreditCardAttribute]
    public string CardNumber { get; set; }
}

Name: CustomValidationAttribute
Description: Specifies a custom validation method that is used to validate a property or class instance.
Usage: [CustomValidation(typeof(Field), "Eval_function")]
Example:

public class CategoryMetadata
   {
      [CustomValidation(typeof(Category), "TestCategoryName")]
      public object CategoryName { get; set; }
   }
 
public static ValidationResult TestCategoryName(string pNewName, ValidationContext pValidationContext)
   {
      if (Regex.IsMatch(pNewName, @"^\d")) // cannot start with a digit
         return new ValidationResult("Cannot start with a digit", new List<string> { "CategoryName" });
      return ValidationResult.Success;
   }

Name: DataTypeAttribute
Description: Specifies the name of an additional type to associate with a data field.
Usage: [DataType(DataType.*)]
Example:

public class DataTypeEntity
{
    [DataType(DataType.Date, ErrorMessage = "Please enter a valid date (ex: 2/14/2011)")]
    public DateTime SaleDate { get; set; }

    [DataType(DataType.EmailAddress)]
    public string EmailAddress { get; set; }
}

Name: DisplayAttribute
Description: Provides a general-purpose attribute that lets you specify localizable strings for types and members of entity partial classes.
Usage: [Display(Name = "*")]
Example:

public class SalesMan
{
    [Required]
    [DisplayName("Full Name :")]
    public string Name { get; set; }

    [Display(Name = "Email address")]
    public string EmailAddress { get; set; }
}

Name: DisplayColumnAttribute
Description: Specifies the column that is displayed in the referred table as a foreign-key column.
Usage: [DisplayColumn("field to use as Foreign Key, Field to use for Sorting, ascending/descending)]
Example:

[DisplayColumn("City", "PostalCode", false)]
public partial class Address
{

}

Name: DisplayFormatAttribute
Description: Specifies how data fields are displayed and formatted by ASP.NET Dynamic Data.
Usage: [DisplayFormat(DataFormatString="*")]
Example:

public class Sale
{
    // Display currency data field in the format $1,345.50.
    [DisplayFormat(DataFormatString="{0:C}")]
    public object StandardCost;
    [DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:dd/MM/yyyy hh:mm}")]
    public DateTime MyDate { get; set; }
}

Name: EditableAttribute
Description: Indicates whether a data field is editable.
Usage: [Editable(AllowEdit=bool,AllowInitialValue=bool)]
Example:

public class Person
{
[Editable(AllowEdit=false)]
 public object Name { get; set; }
 }

Name: EmailAddressAttribute
Description: Validates an email address.
Usage: [EmailAddress]
Example:

public class employee
{
public string Name{get; set;}
[EmailAddress]
public string Notification {get; set;}
}

Name: EnumDataTypeAttribute
Description: Enables a .NET Framework enumeration to be mapped to a data column.
Usage: [EnumDataType(typeof(Enum Type))]
Example:

public enum eReorderLvl {
        zero = 0,
        five = 5,
        ten=10,
        fifteen=15,
        twenty=20,
        twenty_five=25,
        thirty=30
    }
 public class Product_MD {
            [EnumDataType(typeof(eReorderLvl))]
            public object ReorderLevel { get; set; }
        }

Name: FileExtensionsAttribute
Description: Validates file name extensions.
Usage: [FileExtensions(Extensions="*")]
Example:

public class Cliente{
    [FileExtensions(Extensions = "csv,txt",ErrorMessage = "Must choose .csv file.")]
    public string ImportFile{ get; set; }
}

Name: FilterUIHintAttribute
Description: Represents an attribute that is used to specify the filtering behavior for a column.
Usage: [FilterUIHint("The name of the control to use for filtering.")]
Example:

MetadataType(typeof(Product_MD))]
public partial class Product {
    private class Product_MD {
        [FilterUIHint("MultiForeignKey")]
        public object Category { get; set; }
        [FilterUIHint("BooleanRadio")]
        public object Discontinued { get; set; }
    }
}

Name: KeyAttribute
Description: Denotes one or more properties that uniquely identify an entity.
Usage: [Key]
Example:

public class Cliente{
    [Key]
    public int Id { get; set; }
    public string name { get; set; }
}

Name: MaxLengthAttribute
Description: Specifies the maximum length of array or string data allowed in a property.
Usage: [MaxLength(Length)]
Example:

public class Customer
{
    public virtual string CustomerID { get; set; }
    [MaxLength(50, ErrorMessage="Name can not be longer than 50 characters." )]
    public virtual string CompanyName { get; set; }
}

Name: MetadataTypeAttribute
Description: Specifies the metadata class to associate with a data model class.It indicates that a data model class has an associated metadata class. The MetadataType attribute gets a type parameter to specify which type is holding the metadata for the class
Usage: [MetadataType(typeof(MetaData))]
Example:

public class CRMTypeMetadata
{
    [ScaffoldColumn(false)]
    public int TypeID { get; set; }
 
    [StringLength(100)]
    public string Url { get; set; }
}
 
[MetadataType(typeof(CRMTypeMetadata))]
public partial class CRMType
{
}

Name: MinLengthAttribute
Description: Specifies the minimum length of array or string data allowed in a property.
Usage: [MinLength(Length)]
Example:

public class Customer
{
    public virtual string CustomerID { get; set; }
    [MinLength(3, ErrorMessage="Name can not be shorter than 3 characters." )]
    public virtual string CompanyName { get; set; }
}

Name: PhoneAttribute
Description: Specifies that a data field value is a well-formed phone number using a regular expression for phone numbers.
Usage: [Phone]
Example:

public class Customer
{
    public virtual string CustomerID { get; set; }
    [Phone]
    public virtual string Phone_Number { get; set; }
}

Name: RangeAttribute
Description: Specifies the numeric range constraints for the value of a data field.
Usage: [Range(Double,Double)], [Range(Int32,Int32)], [Range(Type,String,String)]
Example:

public class Item
{
public int Id { get; set; }
[Range(10, 1000, ErrorMessage = "Value for {0} must be between {1} and {2}.")]
public Double Weight { get; set; };
}

Name: RegularExpressionAttribute
Description: Specifies that a data field value in ASP.NET Dynamic Data must match the specified regular expression.
Usage: [RegularExpression(@"Regular_Expresion")]
Example:

public class Customer
{
    [RegularExpression(@"[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,4}", ErrorMessage = "Please enter correct email")]
     public string Email { get; set; }
 }

Name: RequiredAttribute
Description: Specifies that a data field value is required.
Usage: [Required()]
Example:

public class Customer
{
    [Required]
    public virtual string CustomerID { get; set; }
    public virtual string CompanyName { get; set; }
}

Name: ScaffoldColumnAttribute
Description: Specifies whether a class or data column uses scaffolding.
Usage: [ScaffoldColumn(true)]
Example:

public class ProductMetadata
{
    [ScaffoldColumn(true)]
    public object ProductID;
    [ScaffoldColumn(false)]
    public object ThumbnailPhotoFileName;
}

Name: ScaffoldTableAttribute
Description: Specifies whether a class or data table uses scaffolding.
Usage: [ScaffoldTable(bool)]
Example:

[MetadataType (typeof(ErrorLogMetada))]
[ScaffoldTable(false)]
public partial class ErrorLog
{
 
}

public class ErrorLogMetada
{

}

Name: StringLengthAttribute
Description: Specifies the minimum and maximum length of characters that are allowed in a data field.
Usage: [StringLength(int maximumLength)]
Example:

public class ProductMetadata
{
    [StringLength(4, ErrorMessage = "The ThumbnailPhotoFileName value cannot exceed 4 characters. ")]
    public object ThumbnailPhotoFileName;

}

Name: TimestampAttribute
Description: Specifies the data type of the column as a row version.Also specifies that this column will be included in the Where clause of Update and Delete commands sent to the database, For concurrency cheking.
Usage: [Timestamp]
Example:

public class Person
{
    public Int64 Id { get; set; }
    public string Name { get; set; }
    [Timestamp]
    public Byte[] Timestamp { get; set; }
}

Name: UIHintAttribute
Description: Specifies the template or user control that Dynamic Data uses to display a data field.
Usage: [UIHintAttribute(string uiHint)]
Example:

public partial class ProductMetadata
{
    [UIHint("UnitsInStock")]
    [Range(100, 10000,
    ErrorMessage = "Units in stock should be between {1} and {2}.")]
    public object UnitsInStock;
}

Name: UrlAttribute
Description: Provides URL validation.
Usage: [Url]
Example:

public class MyModel
{
    [Url]
    public string ServerAddress {get; set;}
}

And that, my Friend, It's all!