What is the simple way to find the column name from Lineageid in SSIS

Question

What is the simple way to find the column name from Lineageid in SSIS. Is there any system variable avilable?

Answer 1

I remember saying this can't be that hard, I can write some script in the error redirect to lookup the column name from the input collection.

string badColumn = this.ComponentMetaData.InputCollection[Row.ErrorColumn].Name;

What I learned was the failing column isn't in that collection. Well, it is but the ErrorColumn reported is not quite what I needed. I couldn't find that package but here's an example of why I couldn't get what I needed. Hopefully you will have better luck.

This is a simple data flow that will generate an error once it hits the derived column due to division by zero. The Derived column generates a new output column (LookAtMe) as the result of the division. The data viewer on the Error Output tells me the failing column is 73. Using the above script logic, if I attempted to access column 73 in the input collection, it's going to fail because that is not in the collection. LineageID 73 is LookAtMe and LookAtMe is not in my error branch, it's only in the non-error branch.

This is a copy of my XML and you can see, yes, the outputColumn id 73 is LookAtme.

<outputColumn id="73" name="LookAtMe" description="" lineageId="73" precision="0" scale="0" length="0" dataType="i4" codePage="0" sortKeyPosition="0" comparisonFlags="0" specialFlags="0" errorOrTruncationOperation="Computation" errorRowDisposition="RedirectRow" truncationRowDisposition="RedirectRow" externalMetadataColumnId="0" mappedColumnId="0"><properties>

I really wanted that data though and I'm clever so I can union all my results back together and then conditional split it back out to get that. The problem is, Union All is an asynchronous transformation. Async transformations result in the data being copied from one set of butters to another resulting in...new lineage ids being assigned so even with a union all bringing the two streams back together, you wouldn't be able to call up the data flow chain to find that original lineage id because it's in a different buffer.

Around this point, I conceded defeat and decided I could live without intelligent/helpful error reporting in my packages.