Conditional Split - Expression Evaluates to Null

Question

Hi everyone!
I'm using a conditional split to discriminate modified records. My expression looks like this:
col1_source != col1_dest || col2_source != col2_des.....and so on. I use OLE DB Command afterward to update modified records.
It all works fine if no columns evaluate to null. If any (source or dest.) evaluates to null, component fails.
Any tips how to solve a problem?
It has to work like this:
If colX_source is null and colX_dest is not null --> Update
If colX_source is not null and colX_dest is null --> Update
If both colX_source and colX_dest are null --> No update
p.s. i apologize if a similar thread exists, I haven't found something of use to me.

Answer 1

Thank you both for a quick response.
I understood the derived column idea but not the isnull idea. 
If I want to cover all the cases in which I want the update to execute, my expression (if I haven’t missunderstood sth) should look like this: 
isNull(col1_source) && !IsNull(col1_dest) || !isNull(col1_source) && IsNull(col1_dest) || col1_source != col1_dest
Isn’t it true that again, the last part of the expression col1_source != col1_dest evaluates to null if one of the columns is null? And that the only solution to the problem is a derived column which transforms null values in “”?
I’m new to SSIS and slowly learning that programming logic is not always the SSIS logic.