MSQL Reference – Measure Operators

The following are the built-in measure (i.e. length/distance/area/relation) operators available in the MSQL language.

ABS/LENGTH/SPAN

@ (x: int64) -> int64

@ (x: float64) -> float64

@(g: [multi]linestring) -> float64

@(g: [multi]polygon) -> float64

@(r: intXrange) -> int64

@(r: floatXrange) -> float64

@(r: timerange) -> timeperiod

In case of a numeric operand, it's an alias for the ABS function; in case of range operand, an alias for RSPAN function; in case of a spatial operand, an alias for ST_LENGTH function.

Return type

Otherwise result is an int64 for integer/integral-range arguments, float64 for floating/floating-range/spatial arguments, and timeperiod for time ranges (rtimestamp and runixepoch).

Null handling

If the operand is NULL, the result will also be NULL.

Examples

SELECT @10;
  --> 10

SELECT @-2.5;
  --> 2.5

SELECT @RANGE(10, 40);
  --> 30

SELECT @RANGE(40, 10);
  --> -30

SELECT @linestring '(0 0, 1000 1000, 2000 0)';
  --> 421.587802

AREA/ABSOLUTE SPAN

@@(r: intXrange) -> int64

@@(r: floatXrange) -> float64

@@(r: timerange) -> timeperiod

@@(g: [multi]polygon) -> float64

Returns the absolute span of a range. In case of spatial operand, an alias for ST_AREA function.

Null handling

If the operand is NULL, the result will also be NULL.

Notes

In the case of a range operand, @@r is equivalent to ABS(RSPAN(r)).

Examples

SELECT @@RANGE(10, 40);
  --> 30

SELECT @@RANGE(40, 10);
  --> 30

SELECT @@polygon '((0 0, 100 0, 100 100, 0 100, 0 0))';
  --> 222.17034400

See also

RSPAN ST_AREA @ (ABS/LENGTH/SPAN)

<-> DISTANCE

(g1: anygeometry) <-> (g2: anygeometry) -> float64

(r1: range[T]) <-> (r2: range[T]) -> T

In case of spatial operands, alias for ST_DISTANCE function. In case of range operands, alias for RDISTANCE function.

Null handling

If any of the spatial operands is empty (e.g. LINESTRING EMPTY), the result will be NULL.

Examples

SELECT point '(11916983 38520414)' <-> point '(12258696 36101539)';
  --> 258938.47

SELECT RANGE(0, 10) <-> RANGE(30, 40);
  --> 20

SELECT RANGE(40, 20) <-> RANGE(-10, -30);
  --> -30

SELECT RANGE(0, 20) <-> RANGE(10, 30);
  --> 0