public static SqlClause AddBetween(this SqlClause sqlClause, [NotNull] string columnName, [CanBeNull] IDbDataParameter parameter, [CanBeNull] IDbDataParameter parameter2) { if (parameter == null && parameter2 == null) { return(sqlClause); } if (parameter == null) { return(sqlClause.AddLessOrEquals(columnName, parameter2)); } if (parameter2 == null) { return(sqlClause.AddGreaterOrEquals(columnName, parameter)); } sqlClause.Add(columnName + " between " + parameter.ParameterName + " and " + parameter2.ParameterName); sqlClause.Add(parameter); sqlClause.Add(parameter2); return(sqlClause); }