Transform
TRANSFORM(g Geometry, srid integer)
Alias: ST_TRANSFORM
Transforms g from one spatial reference system to another. It changes the coordinates of g, but not the SRID of g. Both the SRID being transformed from and to must be in the spatial_ref_sys table.
Result type: geometry
Examples:
Transforms g from 2805 to 4326, SRID of g is not changed:
SELECT SRID(TRANSFORM(POINTFROMTEXT('POINT(49 3)', 2805), 4326));
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col1
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2805
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SELECT ASTEXT(TRANSFORM(POINTFROMTEXT('POINT(49 3)', 2805), 4326));
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col1
--------------------------------
POINT (-73.6508648486344413 34.2444245779162628)
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Transforms g from 2805 to 4326. Also changes SRID of g by getting g in WKB and passing the binary and SRID to GEOMFROMWKB.
SELECT SRID(GEOMFROMWKB(ASBINARY(TRANSFORM(POINTFROMTEXT('POINT(49 3)', 2805), 4326)), 4326));
-------------
col1
-------------
4326
-------------
Transforms g from 2805 to 4326 and back to 2805. SRID of g is still 4326.
SELECT ASTEXTROUND(TRANSFORM(GEOMFROMWKB(ASBINARY(TRANSFORM(POINTFROMTEXT('POINT(49 3)', 2805), 4326)), 4326), 2805), 0);
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col1
--------------------------------
POINT (49 3)
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Last modified date: 01/30/2023