title: SSIS 2012 - passing variables from parent to child package
body: <p>I know this topic has been covered many times, but I have one caveat there that I can't seem to find an answer to . </p>
  
  <p>I have several packages which all have ActivityDate variable. By default, the packages need to run for yesterday's date.  </p>
  
  <p>There are two possible scenarios.  </p>
  
  <p>Scenario 1 - packages are called from a master package.  In this case, ActivityDate is set once, to yesterday's date, in the master package, and then passed down to child packages.</p>
  
  <p>Scenario 2 - packages run stand-alone.  In this case, ActivityDate is set in each child package,  also to yesterday's date, via expression.</p>
  
  <p>In SQL 2008 it was very easy - the variable in each child package vas set via Package Configuration for Scenario 1, but then used expression when run in Scenario 2.</p>
  
  <p>I am unclear how to accomplish this in 2012.   There is no more package configuration, so I need to create package parameter in the child package and then link to it from the parent. But parameters don't use expressions.  So if I create ActivityDate parameter in the child package, then i can link to it from the parent (for Scenario 1), but I can't create an expression for it (for Scenario 2).   And if I have only ActivityDate variable, then I can create an expression, but can't link to it from the parent.<br>
  So how do I make both scenarios work in 2012??  </p>
  
  <p>Help, please!</p>