カテゴリ：: 地理空間関数

ST_DISTANCE¶

Returns the minimum geodesic distance between two GEOGRAPHY or the minimum Euclidean distance between two GEOMETRY objects.

構文¶

ST_DISTANCE( <geography_expression_1> , <geography_expression_2> )

引数¶

geography_expression_1: 引数は GEOGRAPHY 型の式でなければなりません。
geography_expression_2: 引数は GEOGRAPHY 型の式でなければなりません。

戻り値¶

距離をメートルで表す REAL 型の値を返します。

使用上の注意¶

1つ以上の入力ポイントが NULL の場合は NULL を返します。

For GEOMETRY objects, the function reports an error if the two input GEOMETRY objects have different SRIDs.

例¶

GEOGRAPHY Examples¶

これは、赤道に沿って1°離れた2つのポイント間の距離をメートル単位で示しています（約111キロメートルまたは69マイル）。

WITH d AS
    ( ST_DISTANCE(ST_MAKEPOINT(0, 0), ST_MAKEPOINT(1, 0)) )
SELECT d / 1000 AS kilometers, d / 1609 AS miles;
+---------------+--------------+
|    KILOMETERS |        MILES |
|---------------+--------------|
| 111.195101177 | 69.108204585 |
+---------------+--------------+

これは、 NULL 値での ST_DISTANCE 関数の使用を示しています。

SELECT ST_DISTANCE(ST_MAKEPOINT(0, 0), ST_MAKEPOINT(NULL, NULL));
+-----------------------------------------------------------+
| ST_DISTANCE(ST_MAKEPOINT(0, 0), ST_MAKEPOINT(NULL, NULL)) |
|-----------------------------------------------------------|
|                                                      NULL |
+-----------------------------------------------------------+

GEOMETRY Examples¶

The following example compares the distance calculated for GEOGRAPHY and GEOMETRY input objects.

SELECT ST_DISTANCE(TO_GEOMETRY('POINT(0 0)'), TO_GEOMETRY('POINT(1 1)')) AS geometry_distance,
       ST_DISTANCE(TO_GEOGRAPHY('POINT(0 0)'), TO_GEOGRAPHY('POINT(1 1)')) AS geography_distance;

+-------------------+--------------------+
| GEOMETRY_DISTANCE | GEOGRAPHY_DISTANCE |
|-------------------+--------------------|
|       1.414213562 |   157249.628092508 |
+-------------------+--------------------+