This function returns the pcpoint object with the specified sequence number in a pcpatch object.
Syntax
pcpoint ST_pointN(pcpatch pc, integer n);
Parameters
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. |
Examples
SELECT ST_asText(ST_pointN(pa, 4)) FROM patches WHERE id = 7;
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{"pcid":1,"pt":[-126.41,45.59,59,5]}