There are several methods for creating geometries in a database:
INSERT INTO world_cities( country, city, point )
   SELECT country, city, NEW ST_Point( longitude, latitude, 4326 )
      FROM OPENSTRING( FILE 'capitalcities.csv' ) 
           WITH( 
                 country   CHAR(100),
                 city      CHAR(100),
                 latitude  DOUBLE,
                 longitude DOUBLE )
    ALTER TABLE my_table ADD point AS ST_Point(SRID=4326) COMPUTE( NEW ST_Point( longitude, latitude, 4326 ) );