private string GetNullValueOperator(NullValueOperator op) { string opStr = ""; switch (op) { case NullValueOperator.Is: opStr = " is "; break; case NullValueOperator.IsNot: opStr = " is not "; break; } return(opStr); }
/// <summary> /// 指定某列值为NULL的查询。该方法可连续调用。由于使用Where方法指定某列值为null(如:columnName is @arg,@arg为null)时会出错,所以有了该方法。 /// </summary> /// <param name="logicOperator">逻辑操作符</param> /// <param name="columnName">列名</param> /// <param name="valueOperator">值操作符</param> /// <returns></returns> public Command NullWhere(LogicOperator logicOperator, string columnName, NullValueOperator valueOperator) { whereString += GetLogicOperator(logicOperator) + columnName + GetNullValueOperator(valueOperator) + " null "; return(this); }
/// <summary> /// 指定某列值为NULL。该方法可连续调用。 /// </summary> /// <param name="logicOperator">逻辑操作符</param> /// <param name="columnName">列名</param> /// <param name="valueOperator">值操作符</param> /// <returns></returns> public new SelectCommand NullWhere(LogicOperator logicOperator, string columnName, NullValueOperator valueOperator) { base.NullWhere(logicOperator, columnName, valueOperator); return(this); }