Essentially, I need to return a result if row count of result is 1. Meaning if there is more than 1 result for the Select statement it must return nothing.

For example if: `SELECT Person WHERE Job = "Construction" OR "Officer"`

return no results

but if: `SELECT Person WHERE Job = "Clerk"` return the 1 row

[![enter image description here](https://i.stack.imgur.com/wu52f.png)](https://i.stack.imgur.com/wu52f.png)

How can this be done?