The SELECT clause lists the columns to select. COALESCE overlays the
like-named columns. For each row, COALESCE returns the first nonmissing value
of either P2.JOBCODE or P.JOBCODE. Because P2.JOBCODE is the first argument,
if there is a nonmissing value for P2.JOBCODE, COALESCE returns that value.
Thus, the output contains the most recent jobcode information for every employee.
LABEL= assigns a column label.
title 'Most Current Jobcode and Salary Information';
select p.idnumber, coalesce(p2.jobcode,p.jobcode)
label='Current Jobcode',