ST_NumCurves
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Name

ST_NumCurves — Return the number of component curves in a CompoundCurve.

Synopsis

integer ST_NumCurves(geometry a_compoundcurve);

Descrizione

Return the number of component curves in a CompoundCurve, zero for an empty CompoundCurve, or NULL for a non-CompoundCurve input.

Questo metodo implementa la specifica SQL/MM. SQL-MM 3: 8.2.6, 8.3.5

Questa funzione supporta il 3d e non distrugge gli z-index.

Esempi

-- Returns 3
SELECT ST_NumCurves('COMPOUNDCURVE(
    (2 2, 2.5 2.5),
    CIRCULARSTRING(2.5 2.5, 4.5 2.5, 3.5 3.5),
    (3.5 3.5, 2.5 4.5, 3 5, 2 2)
  )');

-- Returns 0
SELECT ST_NumCurves('COMPOUNDCURVE EMPTY');