Friday, 3 June 2011

Often used SSIS expressions

Here is a list of often used SSIS expression which I will expand regularly. You can leave your own handy expression in the comments. Or let me know if you have a better or alternative expression for the expressions below.

And because the expression builder of SSIS is quite worthless, the opensource addon SSIS Expression Editor & Tester could be very useful.

Strings



Filename from pathstring

This expression reverses the string to find the position of the last \ and uses that number (minus 1) in the Right expression:
  • RIGHT([FilePath],FINDSTRING(REVERSE([FilePath]),"\\",1) - 1)
  • RIGHT(@[User::FilePath],FINDSTRING(REVERSE(@[User::FilePath]),"\\",1) - 1)
Folderpath from pathstring
This expressions reverses the string to find the position of the last \ and deduct that number of the total length. After that you can use that number in a substring.
  • SUBSTRING(@[User::FilePath], 1,
    LEN(@[User::FilePath]) - FINDSTRING(REVERSE(@[User::FilePath] ), "\\" ,1 ) + 1
    )
Foldername from the pathstring
This expression finds the last and second last / in the filepath and uses the those positions to find the foldername.
  • SUBSTRING(@[User::FilePath],
    LEN(@[User::FilePath]) - FINDSTRING(REVERSE(@[User::FilePath]),"\\",2) + 2,
    (LEN(@[User::FilePath]) - FINDSTRING(REVERSE(@[User::FilePath]),"\\",1)) - (LEN(@[User::FilePath]) - FINDSTRING(REVERSE(@[User::FilePath]),"\\",2)) - 1
    )
 In SSIS 2012 it's a lot easier/shorter with the token expression:
  • TOKEN(@[User::FilePath],"\\",TOKENCOUNT(@[User::FilePath],"\\") - 1)
 
Default value for an empty string
If you want to give a default value for empty columns, you can check the length or you can check for NULL or you can even check both:
  • LEN([STRING_COLUMN]) == 0 ? "default value" : [STRING_COLUMN]
  • ISNULL([STRING_COLUMN]) ? "default value" : [STRING_COLUMN]
  • ISNULL([STRING_COLUMN]) || LEN([STRING_COLUMN]) == 0 ? "default" : [STRING_COLUMN]

Numbers
Leading zeros
These two expression will add up to 5 leading zeros to a number. So "123" becomes "00123":
  • RIGHT(("00000" + [STRING_COLUMN]), 5)
  • REPLICATE("0", 5 - LEN([STRING_COLUMN])) + [STRING_COLUMN]
Note: you will have to convert a numeric field to string field first with DT_WSTR or DT_STR.

Datetimes
Date from datetime
If you want to remove the time element in a datetime object, you should cast it to DT_DBDATE. But because that datatype is very inconvenient to use, you should cast it back to the original datatype. That will set the time to 0:00.
  • (DT_DATE)(DT_DBDATE)@[User::datetimeVariable]
  • (DT_DATE)(DT_DBDATE)[datetimeColumn]
  • (DT_DBTIMESTAMP)(DT_DBDATE)GETDATE()

Time from datetime
If you want to remove the date element in a datetime object, you should cast it to DT_DBTIME. And optional cast it to a string.
  • (DT_STR,8,1252)(DT_DBTIME)@[User::datetimeVariable]
  • (DT_STR,8,1252)(DT_DBTIME)[datetimeColumn]
  • (DT_STR,8,1252)(DT_DBTIME)GETDATE()

First day of the current month
If you want to get the first day of the current month, you take the current datetime and deduct the current day number (minus 1). Optional you can remove the time part:
  • DATEADD("d", -DAY(GETDATE()) + 1, GETDATE())
  • (DT_DBTIMESTAMP)(DT_DBDATE)DATEADD("d", -DAY(GETDATE()) + 1, GETDATE())

Last dat of the current month
If you want to get the last day of the current month, you add 1 month and deduct the current day number. Optional you can remove the time part:
  • DATEADD("d", -DAY(GETDATE()), DATEADD("m", 1, GETDATE()))
  • (DT_DBTIMESTAMP)(DT_DBDATE)DATEADD("d", -DAY(GETDATE()), DATEADD("m", 1, GETDATE()))
And if you realy want the last second of the current month 30-06-2011 23:59:59
  • DATEADD("s", -1,DATEADD("d", -DAY(GETDATE()) + 1, DATEADD("m", 1, (DT_DBTIMESTAMP)(DT_DBDATE)GETDATE())))

Weeknumber of the month (see)
1-june-2012 is weeknumber 23 in the year, but weeknumber 1 of the month june 2012.
  • (DATEPART("ww",[YourDate]) - DATEPART("ww",DATEADD("d", -DAY([YourDate]) + 1, [YourDate]))) + 1

3 comments:

  1. This is excellent collection. My one cent will be the expression to create a dynamic file with date/timestamp:

    (DT_STR, 4, 1252)DATEPART("yyyy", @[System::StartTime]) +
    RIGHT("0" + (DT_STR, 2, 1252)DATEPART("mm", @[System::StartTime]), 2) +
    RIGHT("0" + (DT_STR, 2, 1252)DATEPART("dd", @[System::StartTime]), 2) +
    RIGHT("0" + (DT_STR, 2, 1252)DATEPART("hh", @[System::StartTime]), 2) +
    RIGHT("0" + (DT_STR, 2, 1252)DATEPART("mi", @[System::StartTime]), 2) +
    RIGHT("0" + (DT_STR, 2, 1252)DATEPART("ss", @[System::StartTime]), 2)

    ReplyDelete
    Replies
    1. Still useful in late 2015! Thanks for saving me the typing (and searching for a datepart parameter reference)

      Delete
  2. A workaround I needed to do for...

    "RIGHT(@[User::FilePath],FINDSTRING(REVERSE(@[User::FilePath]),"\\",1) - 1)"

    ...to keep Expression Builder from complaining about a "-1" in my RIGHT() statement, was to give User::FilePath a dummy default value of "\\blah.txt" so that a "\\" is found, even pre-runtime (at runtime, this is of course replaced by actual file paths from my ForEach enumerator)

    (I added the blah.txt part too because I expanded on this function to also strip out the .txt part because I just wanted filename w/o extension)

    ReplyDelete

Please use the SSIS MSDN forum for general SSIS questions that are not about this post. I'm a regular reader of that forum and will gladly answer those questions over there.

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