c# – SQLite日期和时间数据类型

在SQLite Documentation中,日期和时间数据类型定义如下：

1.2 Date and Time Datatype

SQLite does not have a storage class set aside for storing dates
and/or times. Instead,the built-in Date And Time Functions of SQLite
are capable of storing dates and times as TEXT,REAL,or INTEGER
values:

• TEXT as ISO8601 strings (“YYYY-MM-DD HH:MM:SS.SSS”).
• REAL as Julian day numbers,the number of days since noon in Greenwich on November 24,4714 B.C. according to the proleptic
  Gregorian calendar.
• INTEGER as Unix Time,the number of seconds since 1970-01-01 00:00:00 UTC.

Applications can chose to store dates and times in any of these
formats and freely convert between formats using the built-in date and
time functions.

因此,将我的DateTime值保存为REAL(float)或INTEGER的大小相同.

TEXT格式怎么样？ YYYY-MM-DD HH：MM：SS.SSS中有23个字符.每个字符是8个字节吗？如果是这样,那就是以文本格式存储的巨大空间(这正是我目前所做的).

REAL格式怎么样？我是否定义基准日期为公元前4714年11月24日？ (我甚至不确定Visual Studio 2008是否允许我这样做.我从未尝试过.)然后在我想要的基准日期和日期之间获取TimeSpan,提取天数并存储它？

// is this how to declare this date?
private static readonly DateTime nov24_4714bc = new DateTime(-4714,11,24);

public static double GetRealDate(DateTime dateTime) {
  // FYI: subtracting dates in .NET returns a time span object
  return (dateTime - nov24_4714bc).TotalDays;
}

INTEGER格式怎么样？我会定义1970-01-01 00:00:00 UTC的基准日期(请告诉我该怎么做！),然后在基准日期和输入日期之间获取TimeSpan,提取秒数,并存储？

// is this a UTC date?
private static readonly DateTime utc1970_01_01 = new DateTime(1970,1,1);

public static double GetIntDate(DateTime dateTime) {
  // FYI: subtracting dates in .NET returns a time span object
  return (dateTime - nov24_4714bc).TotalSeconds;
}

对此有何帮助？我有点困惑几点.