protected override Expression VisitConstant(ConstantExpression node) { var expression = base.VisitConstant(node); var type = node.Type; if (IsNullableType(type)) { var genericArgs = type.GetGenericArguments(); if ((genericArgs != null) && (genericArgs.Length == 1)) { type = genericArgs[0]; } } if (type == typeof(byte[])) { MapExpressionToDbExpression(expression, DbExpression.FromBinary((byte[])node.Value)); } else if (type == typeof(bool)) { MapExpressionToDbExpression(expression, DbExpression.FromBoolean((bool?)node.Value)); } else if (type == typeof(byte)) { MapExpressionToDbExpression(expression, DbExpression.FromByte((byte?)node.Value)); } else if (type == typeof(DateTime)) { MapExpressionToDbExpression(expression, DbExpression.FromDateTime((DateTime?)node.Value)); } else if (type == typeof(DateTimeOffset)) { MapExpressionToDbExpression(expression, DbExpression.FromDateTimeOffset((DateTimeOffset?)node.Value)); } else if (type == typeof(decimal)) { MapExpressionToDbExpression(expression, DbExpression.FromDecimal((decimal?)node.Value)); } else if (type == typeof(double)) { MapExpressionToDbExpression(expression, DbExpression.FromDouble((double?)node.Value)); } else if (type == typeof(Guid)) { MapExpressionToDbExpression(expression, DbExpression.FromGuid((Guid?)node.Value)); } else if (type == typeof(Int16)) { MapExpressionToDbExpression(expression, DbExpression.FromInt16((Int16?)node.Value)); } else if (type == typeof(Int32)) { MapExpressionToDbExpression(expression, DbExpression.FromInt32((Int32?)node.Value)); } else if (type.IsEnum) { MapExpressionToDbExpression(expression, DbExpression.FromInt32((Int32)node.Value)); } else if (type == typeof(Int64)) { MapExpressionToDbExpression(expression, DbExpression.FromInt64((Int64?)node.Value)); } else if (type == typeof(float)) { MapExpressionToDbExpression(expression, DbExpression.FromSingle((float?)node.Value)); } else if (type == typeof(string)) { MapExpressionToDbExpression(expression, DbExpression.FromString((string)node.Value)); } else { throw new NotImplementedException(string.Format("Unhandled Type of {0} for Constant value {1} in LambdaToDbExpressionVisitor.VisitConstant", node.Type.Name, node.Value ?? "null")); } return(expression); }