Problem: Cannot complete Exercise 3 in Using ArcMap tutorial
When working with Exercise 3 of the Using ArcMap tutorial, step 4 of the section titled 'Adding a field to an attribute table' returns the error below.
"Failed to add the field to the table/feature class. Cannot create a table with a duplicate column. Field 'POP_DEN' already exists in the table 'tracts'".
There is already a column named POP_DEN in the tracts attribute table.
Solution or Workaround
- Right-click tracts in the table of contents.
- Select Open Attribute Table.
- Right-click the heading for the POP_DEN field in the tracts attribute table.
If you have already completed the 'Joining tables' section of the tutorial and joined the tracts and tract_pop tables, right-click the heading for the tracts.POP_DEN column.
- Select Delete Field.
- Click the Yes button on the Confirm Delete Field dialog box. It is now possible to add the new POP_DEN field to the tracts attribute table.