Database Reference
In-Depth Information
couldprojectthegeometriestoaplanarsystemthatisaccuratefortheareaweare
studyinginthisrecipe(inthiscase,the
ESPG:2163
,
US National Atlas Equal Area
would be a good choice) using the
ST_Transform
function. However, in the case
of large areas like the one we've dealt with in this recipe, casting to geography is
generally the best option, as it gives more accurate results.
The fourth query uses the
ST_Intersects
function. In this case, we grouped by
the
state
columnandusedtwoaggregationSQLfunctions(
SUM
and
COUNT
)toget
the desired results.
Finally,inthelastquery,youupdateaspatialtableusingtheresultsofaspatialjoin.
Theconceptbehindthisislikethatofthepreviousquery,exceptthatitisinthecon-
text of an
UPDATE
SQL command.
