-- Einen Punkt erzeugen
SELECT ST_AsText(ST_GeometryFromText('POINT(7.77777 7.77777)', 4326));

-- Ein Kreis um einen Punkt zeichnen
SELECT ST_AsText(ST_Buffer(ST_GeometryFromText('POINT(-30 -50)', 4326), 10));

-- Schnittmenge zweier kreisförmiger Polygone
SELECT ST_AsText(
  ST_Intersection(
    ST_Buffer(ST_GeometryFromText('POINT(40 30)', 4326), 10),
    ST_Buffer(ST_GeometryFromText('POINT(30 40)', 4326), 10)
  )
);

-- Eine Multigeometrie mit Loch
SELECT ST_AsText(
  ST_Union(
    ST_Difference(
      ST_Buffer(ST_GeometryFromText('POINT(0 0)', 4326), 30),
      ST_Envelope(
        ST_Buffer(ST_GeometryFromText('POINT(0 0)', 4326), 10)
      )
    ),
    ST_Envelope(
        ST_Buffer(ST_GeometryFromText('POINT(-55 -55)', 4326), 10)
      )
  )
);

-- Einen LineString
SELECT ST_AsText(
  ST_MakeLine(
    subselect.point
  )
)
FROM (
  SELECT ST_MakePoint(r1, r2) AS point
  FROM
    generate_series(-45, 45) AS r1,
    generate_series(0, 2) AS r2
) as subselect
;

-- Ein einfaches Polygon mit Loch
SELECT 'POLYGON((0 0, 0 20, 20 20, 20 0, 0 0), (5 5, 5 15, 15 15, 15 5, 5 5))';

-- Informationsabfrage zu obigem Polygon
SELECT ST_Area( 'POLYGON((0 0, 0 20, 20 20, 20 0, 0 0), (5 5, 5 15, 15 15, 15 5, 5 5))'::geometry );

-- Rotiere obiges Loch-Polygon
SELECT ST_AsText( ST_Rotate( 'POLYGON((0 0, 0 20, 20 20, 20 0, 0 0), (5 5, 5 15, 15 15, 15 5, 5 5))'::geometry, radians(315.0))) ;

-- 1000 Zufallspunkte zeichnen (kann ein bisschen dauern)
SELECT ST_AsText(
  ST_Collect(
    ST_MakePoint(
      CASE WHEN random() > 0.5 THEN 1 ELSE -1 END * random() * 180,
      CASE WHEN random() > 0.5 THEN 1 ELSE -1 END * random() * 90
    )
  )
)
FROM generate_series(1, 1000);

-- Zugriff auf in der Datenbank vorgehaltene Liste an Geometrien ${A} --> ${K}
SELECT ST_AsText(
  ST_Collect(subselect.the_geom)
)
FROM (
  SELECT ${A} AS the_geom
    UNION
  SELECT ${B}
    UNION
  SELECT ${C}
    UNION
  SELECT ${D}
    UNION
  SELECT ${E}
    UNION
  SELECT ${F}
    UNION
  SELECT ${G}
    UNION
  SELECT ${H}
    UNION
  SELECT ${I}
    UNION
  SELECT ${J}
    UNION
  SELECT ${K}
) AS subselect;