Simple Data Access in C#

using System;
using System.Data;


namespace Yap.Data.Client
{
	/// <summary>
	/// Represents a parameter to a <see cref="Yap.Data.Client.Command"/>.
	/// </summary>
	[Serializable]
	public class Parameter : IEquatable<Parameter>
	{
		private readonly String _Name;
		private Object _Value;
		private readonly ParameterDirection _Direction = ParameterDirection.Input;
		private readonly Type _ParameterType = typeof(String);
		private readonly Int32? _Size;

		/// <summary>
		/// Gets the name of the parameter.
		/// </summary>
		public String Name
		{
			get { return _Name; }
		}

		/// <summary>
		/// Gets or sets the value of the parameter.
		/// </summary>
		public Object Value
		{
			get { return _Value; }
			set { _Value = value; }
		}

		/// <summary>
		/// Gets the direction of the parameter.
		/// </summary>
		public ParameterDirection Direction
		{
			get { return _Direction; }
		}

		/// <summary>
		/// Gets the type of the parameter.
		/// </summary>
		public Type ParameterType
		{
			get { return _ParameterType; }
		}

		/// <summary>
		/// Gets the size of the parameter.
		/// </summary>
		public Int32? Size
		{
			get { return _Size; }
		}

		/// <summary>
		/// Initializes a new instance of <see cref="Yap.Data.Client.Parameter"/> with specified name.
		/// </summary>
		/// <param name="name">The name of the parameter.</param>
		public Parameter(String name)
		{
			if (String.IsNullOrEmpty(name))
			{
				throw new ArgumentNullException("name");
			}
			_Name = name;
		}

		/// <summary>
		/// Initializes a new instance of <see cref="Yap.Data.Client.Parameter"/> with specified name and value.
		/// </summary>
		/// <param name="name">The name of the parameter.</param>
		/// <param name="value">The value of the parameter.</param>
		public Parameter(String name, Object value)
			: this(name)
		{
			_Value = value;
			if (value != null)
			{
				_ParameterType = _Value.GetType();
			}
		}

		/// <summary>
		/// Initializes a new instance of <see cref="Yap.Data.Client.Parameter"/> with specified name, value and type.
		/// </summary>
		/// <param name="name">The name of the parameter.</param>
		/// <param name="value">The value of the parameter.</param>
		/// <param name="type">The type of the parameter.</param>
		public Parameter(String name, Object value, Type type)
			: this(name, value)
		{
			_ParameterType = type;
		}

		/// <summary>
		/// Initializes a new instance of <see cref="Yap.Data.Client.Parameter"/> with specified name, value and direction.
		/// </summary>
		/// <param name="name">The name of the parameter.</param>
		/// <param name="value">The value of the parameter.</param>
		/// <param name="direction">The direction of the parameter.</param>
		public Parameter(String name, Object value, ParameterDirection direction)
			: this(name, value)
		{
			_Direction = direction;
		}

		/// <summary>
		/// Initializes a new instance of <see cref="Yap.Data.Client.Parameter"/> with specified name, value, type and direction.
		/// </summary>
		/// <param name="name">The name of the parameter.</param>
		/// <param name="value">The value of the parameter.</param>
		/// <param name="type">The type of the parameter.</param>
		/// <param name="direction">The direction of the parameter.</param>
		public Parameter(String name, Object value, Type type, ParameterDirection direction)
			: this(name, value, type)
		{
			_Direction = direction;
		}

		/// <summary>
		/// Initializes a new instance of <see cref="Yap.Data.Client.Parameter"/> with specified name, value, type, size and direction.
		/// </summary>
		/// <param name="name">The name of the parameter.</param>
		/// <param name="value">The value of the parameter.</param>
		/// <param name="type">The type of the parameter.</param>
		/// <param name="size">The size of the parameter.</param>
		/// <param name="direction">The direction of the parameter.</param>
		public Parameter(String name, Object value, Type type, Int32? size, ParameterDirection direction)
			: this(name, value, type, direction)
		{
			_Size = size;
		}
		
		/// <summary>
		/// Determines whether this instance and another specified <see cref="Yap.Data.Client.Parameter"/> object have the same value.
		/// </summary>
		/// <param name="other">Another <see cref="Yap.Data.Client.Parameter"/>.</param>
		/// <returns>true if the value of the other parameter is the same as this instance; otherwise, false.</returns>
		public Boolean Equals(Parameter other)
		{
			if (other == null)
			{
				return false;
			}
			return
				Equals(Name, other.Name) &&
				Equals(Value, other.Value) &&
				Equals(ParameterType, other.ParameterType) &&
				Equals(Size, other.Size) &&
				Equals(Direction, other.Direction);
		}

		/// <summary>
		/// Determines whether this instance of <see cref="Yap.Data.Client.Parameter"/> and a specified object, which must also be a <see cref="Yap.Data.Client.Parameter"/> object, have the same value.
		/// </summary>
		/// <param name="obj">An <see cref="System.Object"/>.</param>
		/// <returns>true if obj is a <see cref="Yap.Data.Client.Parameter"/> and its value is the same as this instance; otherwise, false.</returns>
		public override Boolean Equals(Object obj)
		{
			return Equals(obj as Parameter);
		}

		/// <summary>
		/// Returns the hash code for this parameter.
		/// </summary>
		/// <returns>The hash code for this parameter.</returns>
		public override Int32 GetHashCode()
		{
			return Name.GetHashCode();
		}

		/// <summary>
		/// Returns a string representation of the parameter.
		/// </summary>
		/// <returns>A string representation of the current parameter.</returns>
		public override String ToString()
		{
			return Name;
		}
	}
}