[dba-SQLServer] Percent Rank Function in SQL

I need to use a Percent Rank function to determine which students are in the
lowest 25% of a school.  We sort then rank the prior year developmental
scale score by previous year's grade level.  Any ties need to be ranked
down.  Then we flag the students whose rank is 25.44 or below as in the
lowest 25%.  We do this for each grade level of the school (grade 3 - 10).
If there are less than 30 students in the lowest 25% of the school then we
need to resort all of the rankings in the school and flag the lowest 30
students.  This is a separate calculation and only really needs to be done
if the lowest 25% does not contain enough students.  I hope this explanation
is good enough to get someone to put me on the track of finding a Percent
rank function.  Thanks for all your help.

 

Susan Klos

Senior Database Analyst

Evaluation and Reporting

Florida Department of Education

850-245-0708 

sc 205-0708