ST_Point — Creates a Point with the given coordinate values. Alias for ST_MakePoint.
geometry ST_Point(float x, float y
Returns an Point with the given X and Y coordinate values. This is the SQL-MM alias for ST_MakePoint that takes just X and Y.
For geodetic coordinates,
This method implements the SQL/MM specification. SQL-MM 3: 6.1.2
SELECT CAST(ST_SetSRID( ST_Point( -71.104, 42.315), 4326) AS geography);
PostgreSQL also provides the
:: short-hand for casting
SELECT ST_SetSRID( ST_Point( -71.104, 42.315), 4326)::geography;
If the point coordinates are not in a geodetic coordinate system (such as WGS84), then they must be reprojected before casting to a geography. In this example a point in Pennsylvania State Plane feet (SRID 2273) is projected to WGS84 (SRID 4326).
SELECT ST_Transform(ST_SetSRID( ST_Point( 3637510, 3014852 ), 2273), 4326)::geography;