Question

I need to check if a value lies in a range, however I can’t guarantee that either end of the range isn’t NULL. The values in this case are integers. ‘mo‘ represents employment

currently I have the following

WHERE (r.year BETWEEN mo.startyear AND mo.endyear >= r.year) 
OR (mo.startyear <= r.year AND mo.endyear IS null)
OR (mo.startyear IS null AND mo.endyear IS null)
OR (mo.startyear IS null AND mo.endyear >= r.year)

is this the only way to check the mo was ’employed’ at a particular year (r)

Answer 1

How about:

WHERE ( mo.startyear <= r.year OR mo.startyear IS NULL )
  AND ( mo.endyear >= r.year OR mo.endyear IS NULL )