Update + st_within

Question

I want update table A.localidad, using st_within table B.licalidad

I need make centroid from table a for more precision.

The error, is the subquery return more one row

update test.test set 
localidad = (select st_within (st_centroid(a.geom), b.geom) from test.test a, capas_gral.localidades_amba b)

ERROR: una subconsulta utilizada como expresión retornó más de un registro (translation via Google: a subquery used as an expression returned more than one record)

Answer 1

Try the following:

Updates column localidad of table test.test to take value of table capas_gral.localidades_amba where the centroid of test.test is completely inside capas_gral.localidades_amba.

UPDATE test.test
SET localidad = b.localidad 
FROM capas_gral.localidades_amba b
WHERE ST_WITHIN(st_centroid(test.test.geom), b.geom)