"The quantity takeoff is incorrect due to the column and wall junction."

[soyhannnnn]

"The quantity takeoff in Revit is incorrect because the column continues through the wall. What should be the solution for this?"

[barthbradley]

Unjoin and split the wall in two at the column.  

...switch join order might get you there as well.  

https://www.youtube.com/watch?v=dxwfIbEw-24&t=3s

[vitorbortoncello]

To complement BarthBradley's reply, it's also important to disallow join at wall ends to ensure accurate wall length and quantity takeoffs

[ToanDN]

To get correct quantity take off, create parts from building components and schedule parts material take-off. You can further refine parts geometry by enable geometry grips to stretch parts, along with merge/ exclude parts, without messing up with the original building components.