Sorting Access Data (date times in the wrong format)

Question

Problem:

Some of the fields in my table have the wrong format for a date, they're formatted using the .ToString() Method in C# but i made a typo and entered it like this : MM/dd/yyyy hh:mm/ss tt

Now, if you look closely you see MM/dd/yyyy hh:mm ----> ' / ' <--- ss

which is suppose to be a ' : '

I then preceded to fix it in my c# code, (meaning some of the values are formatted: MM/dd/yyyy hh:mm:ss tt )

The problem is, i'm trying to select values from the table in order of Date (which i can't just Sort by 'Datefieldnamehere') because some of the fields are in the wrong format with a '/'

---

What i have Tried:

Now, i figured since the time is always in the same spot (and that's what matters to me) i could just take the substring of the numbers in the time and order them; first for AM then for PM

I could Order By MID([ColumnName],11,2) , MID([ColumnName],14,2), MID([ColumnName],16,2) because every date regardless of the delimiter is always in the format M/dd/yyyy hh/mm/ss tt

So I Tried:

---

(
SELECT SN, StatusCode, Time, Mid(Time,14,2) + ':'+ Mid(Time,17,2) AS TTI
FROM OrderStatus
WHERE StatusCode = 'Finished' and Left(Time,10) = '4/20/2012'
AND Time LIKE '*AM'
ORDER BY Val(Mid([Time],11,2)) DESC
)
UNION ALL (
SELECT SN, StatusCode, Time, Mid(Time,14,2) + ':'+ Mid(Time,17,2) AS TTI
FROM OrderStatus
WHERE StatusCode = 'Finished' and Left(Time,10) = '4/20/2012'
AND Time LIKE '*PM'
ORDER BY Val(Mid([Time],11,2)) DESC
);

---

Just to see if that would Order it by hour but it doesn't it gives me this :

As you can see it goes (in the hour field) 01 then 02 and then it goes back to 01... ?

Anyway there's a similar question here That i have put a bounty on, you will earn the bounty if you answer this question or that question, this would be useful to know for other scenarios as well

Edit: The Question that i really want answered how to sort by a Substring of a string; sorry for the late edit i could of swore i changed this already, say i want to sort by a single digit of any string / date / anything i was wondering how i can do something like: Order By Val(Mid(ColumnName,StartPos,EndPos))

Note: That Order By gives completely wrong results.

Answer 1

My instinct is to create a function and run it once in an Access UPDATE statement to convert the stored values to match the desired format.

The quick & dirty function below copes with both single and two digit months. It requires Access 2000 or later.

? FixTimeData("4/20/2012 01:34/09 PM")
4/20/2012 01:34:09 PM
? FixTimeData("12/20/2012 01:34/09 PM")
12/20/2012 01:34:09 PM

Public Function FixTimeData(ByVal pIn As String) As String
    Dim astrPieces() As String
    Dim strOut As String
    astrPieces = Split(pIn, " ")
    strOut = astrPieces(0) & " " & _
        Replace(astrPieces(1), "/", ":") & " " & _
        astrPieces(2)
    FixTimeData = strOut
End Function

Then an UPDATE statement similar to this ...

UPDATE OrderStatus
SET time_field = FixTimeData(time_field)
WHERE time_field Like "*/*/*/*";

If you run the statement under ADO instead of DAO, change to ANSI wild card characters in the WHERE clause.

WHERE time_field Like "%/%/%/%";

Or use ANSI wild cards with ALike if you want the same statement to work under either ADO or DAO.

WHERE time_field ALike "%/%/%/%";

I used time_field as the field name where you used Time because Time is a reserved word. If you can't change the field name, enclose it with square brackets in your query.

Edit : My intention was to fix the data so you can then sort reliably based on Right(time_field, 11)

Edit2 : To sort based on the "upper" minute digit, see if you can build on this approach, which assumes you have fixed the stored date/time strings:

? Left(Format(Minute("4/23/2012 04:02:40 PM"), "00"), 1)
0
? Left(Format(Minute("4/23/2012 04:12:40 PM"), "00"), 1)
1
? Left(Format(Minute("4/23/2012 04:22:40 PM"), "00"), 1)
2

Although the Minute() function accepts a string, I would likely use CDate() to explicitly transform the string to a Date/Time before feeding it to Minute() .

So ... if I haven't gone completely astray ... try that approach in a query like this:

SELECT
    Left(Format(Minute(CDate(time_field)), "00"), 1) AS upper_minute,
    OrderStatus. *
FROM OrderStatus
ORDER BY 1;

Answer 2

Make date filed to be real date field instead of string. Migrate all values to new field with 2 updates - one that selects all rows with old format, another with new. Drop string column for date and enjoy properly typed data.

If you really want to keep it as string at least make sure to use standard ISO8601 format (approximately YYYY-MM-DDTHH:MM.ssss) that is safe for sorting/localization.

Answer 3

I don't have a table to test, however I want to give my idea.
I will use the Left, Mid and Right function together with CDate and CInt functions.
I will get the leftmost part of Time Field (16 bytes), add a ":00" for the seconds and the PM/AM designator. This string can be converted to a date using CDate.
Then I will get the seconds part and convert them to an integer.
Now the order by could be reached ordering for the first part (TTI) and then for the second part (TTS) without using an UNION.
But there is a problem, some dates contains a month with only 1 char, (es: 4 april vs 12 december) luckily, we can use the IIF operator to select the right numbers for mid, right and left.

EDIT:

SELECT 
SN, StatusCode, Time, 
IIF(Len(Time) = 22, Left(Time,16) + ':00' + Right(Time,2), Left(Time,15) + ':00' + Right(Time,2)) AS TTI, 
IIF(Len(Time) = 22, Mid(Time, 18,2), Mid(Time, 17,2)) as TTS
FROM OrderStatus 
WHERE StatusCode = 'Finished' and Left(Time,10) = '4/20/2012' 
ORDER BY CDate(IIf(Len([Time])=22,Left([Time],16)+ ':00 ' + Right([Time],2),Left([Time],15)+ ':00 ' + Right([Time],2))) DESC , 
         CInt(IIf(Len([Time])=22,CInt(Mid([Time],18,2)),CInt(Mid([Time],17,2)))) DESC;