Question

I’ve played a little with SQLite in the past, and I like it enough that I want to use it for a new project.

Step 1 is creating the database, and I need to create a DateStamp field where I place a time stamp on when an event occurred.

In the SQLite Documentation, the Date and Time Datatype is defined as follows:

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.

I’d rather not save dates as text, and since the Windows DateTime object does not go back to November 24, 4714 B.C., I supposed I’m left with storing DateTime values as an INTEGER.

So, how do I store the DateTime as an Integer? Would I get the TimeSpan between base date and date I want, extract the number of days, and store that?

// 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;
}

Is that right? Is this what everyone else is doing that uses SQLite?

It also says that SQLite stores datetime in UTC time, so I need to convert again on top of that.

Surely someone has done this before. I would appreciate seeing tools someone has made already that handles these inputs. SQLite has some built in functions, but I don’t really understand how to use them.

Solved:

Well poo.

Could it be as simple as this?

public static long ToFileTimeUtc(DateTime dateTime) {
  return dateTime.ToFileTimeUtc();
}

public static DateTime FromFileTimeUtc(long fileTimeUtc) {
  return DateTime.FromFileTimeUtc(fileTimeUtc);
}

Comments?

Can I not do that?

Answer 1

Well poo.

Could it be as simple as this?

public static long ToFileTimeUtc(DateTime dateTime) {
  return dateTime.ToFileTimeUtc();
}

public static DateTime FromFileTimeUtc(long fileTimeUtc) {
  return DateTime.FromFileTimeUtc(fileTimeUtc);
}

Comments?

Can I not do that?