Forum Discussion
Can I Use the VLOOKUP Formula to Return a Data Validation Drop Down List?
No, you can't use VLookup, but you could still add data validation. The caveat is that you can't have user input and a lookup formula in the same cell, so you would need to add a column for user selection from the data validation list. Then, using an IF formula in the instructor field, you can perform a lookup when there is only one instructor, or pull from the user's selection from the data validation when there is more than one.
VLOOKUP only returns the first instance in the match. A better alternative is to create a new column in Table 1 that can be used a reference for future lookups. This can be a Unique ID for the courses.
Now when referencing Courses in Table 2, the Unique ID will always return the respective instructor even if the course list is repeated, since the Unique ID is unique. That is the essence of working with relational databases in Excel.