Passing variables from a Parent Package To a Child - part II

Case
A few months ago I did a post on how to pass the value of a parent package to a child package. That solution consisted on a peace of .Net coding in a Script Task. But there is an other solution for those who don't like .Net coding.

Solution
This solution consists of using the package configuration.

1) Create parent variable
Create a variable in your parent package. Right click in the Control Flow if the variables are not visible. I used a string variable named FilePath in this test case to store some filepath.

Create new variable, think about the scope.

2) Create Execute Package Task
Drag an Execute Package Task in your Control Flow and configure it to start your child package.

Execute Package Task

3) Create child variable
Goto to your child package and create a variable with the same name as your parent package variable.

Same name!

4) Add configurations
In the SSIS menu choose Package Configurations.

Package Configurations

5) Configuration Type
Enable package configuration(1) and add a configuration. Choose Parent package variable(2) and type the name of the variable(3).

Parent package variable

6) Select Target Property
After you typed the name of the variable, hit the next button and select the value property of the child package variable. After that hit Next, Finish and OK to complete the configuration.

Value property of the child package variable

7) Testing
To test the package I added a simple Script Task (sorry for .net coding) with a messagebox to show the value of the parent package.

Little bit of coding, but just for the show.

The SSIS solution can be downloaded here.

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