clarify TeacherAppointment.schNo vs Establishment.schNo

[Brian Lewis]

Originally, teacherAppointment School number was usually left null, the school no of the appointment coming from the schNo on the Establishment (position) record.

However, the model allows for "supernumerary", or "floating" positions; that are positions in the Establishment that are tied tied to a given school. These could be allocated to teachers, e.g. on paid study leave.

a supernumerary position is allocated to the education authority - these are indicated by the flag estpScope = 'A'. These should be the only records in Establishment with null schNo.

A floating position may be allocated to any school (withi the authority). So, in this case TeacherAppointment.schNo is set, Establishment.schNo is null, and Establishment.estpScore = 'A'

This creates an issue for stored proc pTeacherRead.TeacherListByAppointment - does it get the schNo from TeacherAppointment or Establishment?

this was changed in Solomon Islands from TA to EST, but the most correct answer is to coalesce these values. change this stored proc accordingly

[Brian Lewis]

change to stored proc as described pull request #166