This function returns the pcpoint object with the specified sequence number in a pcpatch object.


pcpoint ST_pointN(pcpatch pc, integer n);


Parameter Description
pc The pcpatch object.
n The sequence number of the pcpoint object, starting from 1. If n is a negative number, it specifies the pcpoint object with the sequence number of |n| starting from the end of the pcpatch object reversely. For example, a value of -2 indicates the last but one pcpoint object in the pcpatch object.


SELECT ST_asText(ST_pointN(pa, 4)) FROM patches WHERE id = 7;