--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Source/Data/Sql/SqlValue.cs	Thu Mar 27 21:46:09 2014 +0400
@@ -0,0 +1,138 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace BLToolkit.Data.Sql
+{
+    public class SqlValue : SqlValueBase, ISqlExpression
+	{
+		public SqlValue(Type systemType, object value)
+		{
+			_systemType = systemType;
+			_value = value;
+		}
+
+		public SqlValue(object value)
+		{
+			_value = value;
+
+			if (value != null)
+				_systemType = value.GetType();
+		}
+
+		public override object Value
+		{
+			get
+			{
+				var rv = base.Value;
+
+				if (rv != null && rv.GetType() != _systemType)
+				{
+					_systemType = rv.GetType();
+				}
+
+				return rv;
+			}
+		}
+
+		Type _systemType; public Type    SystemType { get { return _systemType; } }
+
+		#region Overrides
+
+#if OVERRIDETOSTRING
+
+		public override string ToString()
+		{
+			return ((IQueryElement)this).ToString(new StringBuilder(), new Dictionary<IQueryElement,IQueryElement>()).ToString();
+		}
+
+#endif
+
+		#endregion
+
+		#region ISqlExpression Members
+
+		public int Precedence
+		{
+			get { return Sql.Precedence.Primary; }
+		}
+
+		#endregion
+
+		#region ISqlExpressionWalkable Members
+
+		ISqlExpression ISqlExpressionWalkable.Walk(bool skipColumns, Func<ISqlExpression,ISqlExpression> func)
+		{
+			return func(this);
+		}
+
+		#endregion
+
+		#region IEquatable<ISqlExpression> Members
+
+		bool IEquatable<ISqlExpression>.Equals(ISqlExpression other)
+		{
+			if (this == other)
+				return true;
+
+			var value = other as SqlValue;
+			return
+				value       != null              &&
+				_systemType == value._systemType &&
+				(_value == null && value._value == null || _value != null && _value.Equals(value._value));
+		}
+
+		#endregion
+
+		#region ISqlExpression Members
+
+		public bool CanBeNull()
+		{
+			return Value == null;
+		}
+
+		public bool Equals(ISqlExpression other, Func<ISqlExpression, ISqlExpression, bool> comparer)
+		{
+			return ((ISqlExpression)this).Equals(other) && comparer(this, other);
+		}
+
+		#endregion
+
+		#region ICloneableElement Members
+
+		public ICloneableElement Clone(Dictionary<ICloneableElement, ICloneableElement> objectTree, Predicate<ICloneableElement> doClone)
+		{
+			if (!doClone(this))
+				return this;
+
+			ICloneableElement clone;
+
+			if (!objectTree.TryGetValue(this, out clone))
+				objectTree.Add(this, clone = new SqlValue(_systemType, _value));
+
+			return clone;
+		}
+
+		#endregion
+
+		#region IQueryElement Members
+
+		public QueryElementType ElementType { get { return QueryElementType.SqlValue; } }
+
+		StringBuilder IQueryElement.ToString(StringBuilder sb, Dictionary<IQueryElement,IQueryElement> dic)
+		{
+			return
+				Value == null ?
+					sb.Append("NULL") :
+				Value is string ?
+					sb
+						.Append('\'')
+						.Append(Value.ToString().Replace("\'", "''"))
+						.Append('\'')
+				:
+					sb.Append(Value);
+		}
+
+		#endregion
+	}
+}