Use sparse data from a list of fields to populate a new field by iterating over a list of fields and selecting the next value in the list.
"SELECT > 'destination_field' < ['source_field', 'source_field', etc.]"
Where order of
source_field is important, each successive field in the list has priority over the ones before
it (e.g. for columns A, B & C, values in C will have precedence over values in B and A). If there are nulls in
A and B, but not B, then the returned value will be from B. If, however, there are values in A, B and C, then
the returned value will be from C.
"SELECT > 'occupation_state_date' < ['Account Start date', 'Current Relief Award Start Date']"
In this example, any dates in
Current Relief Award Start Date will have precedence over
Account Start date
while nulls will be ignored, ensuring that
Account Start date will be returned.