fetchRow
Executes the query and returns its single row, or null when nothing matched.
At most two rows are requested, so a query that accidentally matches a million does not cross the wire before failing.
Return
The single row, or null if there were none.
Parameters
params
Values by parameter name, without the leading @.
Throws
INCORRECT_RESULT_SIZE if more than one row matched, MISSING_NAMED_PARAMETER if the statement names a parameter params omits.
Same as fetchRow, with the values given as Pairs.