One of the common problems that beginners have with SSIS is debugging errors involving variables. One example of this occurs when a package uses a Foreach Loop container. These are often used to set a variable value differently for each iteration of a loop. If something fails during the loop, you might want to check the value of the variable in order to determine what went wrong.
Fortunately, this is pretty easy to accomplish in SSIS. You can see the value of any package variable in BIDS when you debug the package by following the steps below:
This is a useful technique for troubleshooting packages that use variables, particularly if the variable values are changed during package execution.
Moreover, this technique allows you to see the value of variables that are evaluated as expressions and hence I always advocate putting expressions into variables rather than applying them to Container/ConnMan properties directly.
-Jamie