## Name

GetNodeByPoint — Find the id of a node at a point location

## Synopsis

`integer `**GetNodeByPoint**(

varchar `atopology`, geometry `point`, float8 `tol``)`

;

## Retrieve the id of a node at a point location

The function return an integer (id-node) given a topology, a POINT and a tolerance. If tolerance = 0 mean exactly intersection otherwise retrieve the node from an interval.

If there isn't a node at the point, it return 0 (zero).

If use tolerance > 0 and near the point there are more than one node it throw an exception.

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If tolerance = 0, the function use ST_Intersects otherwise will use ST_DWithin. |

Availability: 2.0.0 - requires GEOS >= 3.3.0.

## Examples

These examples use edges we created in AddEdge

SELECT topology.GetNodeByPoint('ma_topo',geom, 1) As nearnode
FROM ST_GeomFromEWKT('SRID=26986;POINT(227591.9 893900.4)') As geom;
nearnode
----------
2

SELECT topology.GetNodeByPoint('ma_topo',geom, 1000) As too_much_tolerance
FROM ST_GeomFromEWKT('SRID=26986;POINT(227591.9 893900.4)') As geom;
----get error--
ERROR: Two or more nodes found