Developing Next Generation Smart Clients using .NET 2.0 working with Existing .NET 1.1 SOA-based XML Web Services

using System;
using System.Data;

namespace SmartInstitute.DataAccessLayer
{

#region Repository Enumerations
		#region Load/Save Enums

		/// <summary>
		/// DeepLoad options for deep loading entities
		/// </summary>
		public enum DeepLoadType : int
		{
			/// <summary>
			/// Will Include a child property collection 1 Level Deep
			/// </summary>
			IncludeChildren = 1,
			
			/// <summary>
			/// Will Exclude a child property collection
			/// </summary>
			ExcludeChildren = 2,
						
			/// <summary>
			/// Will ignore the request and return the entity.
			/// </summary>
			Ignore = 3
		}

		/// <summary>
		/// DeepSave options for deep saving entities
		/// </summary>
		public enum DeepSaveType : int
		{
			/// <summary>Will Include a child property collection</summary>
			IncludeChildren = 1,

			/// <summary>Will Exclude a child property collection</summary>
			ExcludeChildren = 2,

			/// <summary>Will ignore the request and return the entity.</summary>
			Ignore = 3
		}
		#endregion
		
#endregion

		
	/// <summary>
	/// Contains some helper function for SQL.
	/// </summary>
	public sealed class CommonSql
	{
		private CommonSql()
		{
			// All static methods
		}

		#region Helper Methods
		/// <summary>
		/// Get a default value for a given data type
		/// </summary>
		/// <param name="dataType">Data type for which to get the default value</param>
		/// <returns>An object of the default value.</returns>
		public static Object GetDefaultByType(DbType dataType)
		{
			switch (dataType)
			{
				case DbType.AnsiString: return string.Empty;
				case DbType.AnsiStringFixedLength: return string.Empty;
				case DbType.Binary: return 0;
				case DbType.Boolean: return false;
				case DbType.Byte: return 0;
				case DbType.Currency: return 0;
				case DbType.Date: return DateTime.MinValue;
				case DbType.DateTime: return DateTime.MinValue;
				case DbType.Decimal: return 0;
				case DbType.Double: return 0;
				case DbType.Guid: return Guid.Empty;
				case DbType.Int16: return 0;
				case DbType.Int32: return 0;
				case DbType.Int64: return 0;
				case DbType.Object: return null;
				case DbType.Single: return 0;
				case DbType.String: return String.Empty;
				case DbType.StringFixedLength: return string.Empty;
				case DbType.Time: return DateTime.MinValue;
				case DbType.VarNumeric: return 0;
				default: return null;
			}
		}

		/// <summary>
		/// Get Value or Default Value from an IDataParamater
		/// Based on DbType
		/// </summary>
		/// <param name="p">The IDataParameter instance type is used to determine the default value.</param>
		/// <returns></returns>
		public static Object GetDataValue(IDataParameter p)
		{
			if (p.Value != DBNull.Value) 
				return p.Value;
			else
				return GetDefaultByType(p.DbType);
		}

		/// <summary>
		/// Checks to see if the Default Value has been set to the parameter.
		/// If it's the default value, then create.
		/// </summary>
		/// <param name="val">The value we want to check.</param>
		/// <param name="dbtype">The DbType from wich we take the default value.</param>
		/// <returns></returns>
		public static object DefaultToDBNull(object val, DbType dbtype){
			if (val == null || Object.Equals(val, GetDefaultByType(dbtype)))
				return System.DBNull.Value;
			else
				return val;
		}
		#endregion

	}
}