Frequent tipster Danny Korem shares a technique he uses during AutoCAD data extraction to ensure that he doesn’t duplicate data.
"The latest versions of AutoCAD all have built-in data-extraction functionality — the ability to link between DWG components and their derivatives within electronic spreadsheets (in both directions, and more). At the end of the day, accuracy while counting objects within drawings is crucial and, in spite of great functionality, there are some possible failure points that must be considered before the real procedure starts its run: Is it possible that blocks with attributed data that is to be extracted have unnecessary duplicates? Is it possible that each duplicate resides in a different layer?
"If one of the blocks is on a locked layer or the Delete Duplicate Objects command (also known as Overkill) has the wrong set of parameters, it makes it difficult to clean up your file. Well, one of the critical phases in the procedure to help deal with this issue is to have an invisible attribute quoting the location (x,y coordinates), which can be extracted later. This way, you'll be able to easily determine if any duplicates exist in the data extraction source (DWG objects). If so, stop and relate to, and finally, resume the procedure."
Notes from Cadalyst Tip Reviewer Brian Benton: This is a good tip that can help you check your data. If the x,y,z coordinates are duplicated, then the data is likely to have been duplicated as well. Making a unique field to hold the data also makes it easier to find the data.