ST_MapPolygonsToGrid

Map polygon geometries that are contained in a table to grid cells.

Syntax

ST_MapPolygonsToGrid(gridsize, table, col[, debug[, srid[, idcol[, includeAllCols]]]])

gridsize

The grid size in degrees. Possible values:

1
0.1
0.01

If the grid table doesn't already exist, it will be created.

Type: DOUBLE

table

The table that contains the polygons to be mapped.

Type: VARCHAR(ANY)

col

The column that contains the polygons to be mapped.

Type: VARCHAR(ANY)

debug

Whether to enable debug messages and preserve all intermediate tables.

Type: BOOLEAN

Default: FALSE

srid

The SRID used to initialize the grid.

Type: INTEGER

idcol

The column of the input table that contains the identifier of each of the input polygon geometries.

Type: VARCHAR(ANY)

includeAllCols

If the value of this parameter is TRUE, the output table is augmented to include, in addition to its other columns, all the columns of the input table.

Type: BOOLEAN

Default: FALSE

Returns

This function returns two outputs:

A value of type INTEGER that is 0 if the function was successful or 1 if an error occurred.
A table with one row for each intersection of an input polygon geometry with a grid cell. Each row of the output table has the following columns:

ID_COLUMN

The identifier from the column of the input table that was specified by the idcol parameter.

GEOM_COLUMN

GRID_ID

GRID_GEOMETRY

Examples

set PATH=inza.inza;
 
create table POINTS (ID INTEGER, MY_GEOM ST_GEOMETRY(64000)); insert into POINTS VALUES (1,
            inza..ST_WKTToSQL('Point (1.1 1.1)'));
 
insert into POINTS VALUES (2, inza..ST_WKTToSQL('Point (2.2 2.2)'));
insert into POINTS VALUES (3, inza..ST_WKTToSQL('Point (3.3 3.3)'));

alter table points owner to inzauser;

call inza..ST_MAPPOLYGONSTOGRID(1,'POINTS','MY_GEOM',false,4326,'ID',true);


select ID, inza..ST_ASTEXT(MY_GEOM), ONEGID, inza..ST_ASTEXT(ONEGRID_GEOM) from POINTS_ONE_GRIDMAP; 

drop table POINTS_ONE_GRIDMAP;
drop table POINTS;
drop table GRID_ONE_GEOMETRIES;
delete from GEOMETRY_COLUMNS where F_TABLE_NAME='POINTS_ONE_GRIDMAP';

ST_MAPPOLYGONSTOGRID
--------------------
0
(1 row) 

ID |      ST_ASTEXT  | ONEGID | ST_ASTEXT
---+-----------------+--------+-------------------------------------
 2 | POINT (2.2 2.2) |  92182 | POLYGON ((2 2, 3 2, 3 3, 2 3, 2 2))
 3 | POINT (3.3 3.3) |  93183 | POLYGON ((3 3, 4 3, 4 4, 3 4, 3 3)) 
 1 | POINT (1.1 1.1) |  91181 | POLYGON ((1 1, 2 1, 2 2, 1 2, 1 1))
(3 rows)