Postgres/PostGIS st_distance_sphere 函数与 EntityManager.createQuery 无法理解的错误答案

【问题标题】：Postgres/PostGIS st_distance_sphere function with EntityManager.createQuery incomprehensible errorPostgres/PostGIS st_distance_sphere 函数与 EntityManager.createQuery 无法理解的错误
【发布时间】：2019-11-25 14:35:56
【问题描述】：

我尝试使用 PostGIS 计算两点之间的距离。我发现 postGIS 为此有st_distance_sphere function，并尝试了以下代码：

private fun getDeliveryDistance(areaCentroid: Point, buyerLocation: Point): Double {
    val query = em.createQuery(
        "select st_distance_sphere(st_makepoint(${areaCentroid.x}, ${areaCentroid.y}), st_makepoint(${buyerLocation.x}, ${buyerLocation.y}))",
        Double::class.java
    )
    val result = query.singleResult
    return result
}

但是我得到了以下错误，而不是正确的结果：

java.lang.IllegalArgumentException: org.hibernate.QueryException: No data type for node: org.hibernate.hql.internal.ast.tree.MethodNode 
 \-[METHOD_CALL] MethodNode: '('
    +-[METHOD_NAME] IdentNode: 'st_distance_sphere' {originalText=st_distance_sphere}
    \-[EXPR_LIST] SqlNode: 'exprList'
       +-[METHOD_CALL] MethodNode: '('
       |  +-[METHOD_NAME] IdentNode: 'st_makepoint' {originalText=st_makepoint}
       |  \-[EXPR_LIST] SqlNode: 'exprList'
       |     +-[NUM_DOUBLE] LiteralNode: '38.970335125923135'
       |     \-[NUM_DOUBLE] LiteralNode: '45.0543938370861'
       \-[METHOD_CALL] MethodNode: '('
          +-[METHOD_NAME] IdentNode: 'st_makepoint' {originalText=st_makepoint}
          \-[EXPR_LIST] SqlNode: 'exprList'
             +-[NUM_DOUBLE] LiteralNode: '38.97033512592316'
             \-[NUM_DOUBLE] LiteralNode: '45.05439383708615'
 [select st_distance_sphere(st_makepoint(38.970335125923135, 45.0543938370861), st_makepoint(38.97033512592316, 45.05439383708615))]]

不幸的是，我不知道这个错误。但是，当我在调用getSingleResult() 之前以调试模式或从堆栈跟踪的最后一行复制查询，然后在 pgAdmin 控制台中执行它时，我得到了正确的结果。有人知道我该如何解决吗？

【问题讨论】：

标签： postgresql hibernate kotlin spring-data-jpa postgis

【解决方案1】：

@Query(
    """select topology.st_distance(topology.st_makepoint(:restaurantLat, :restaurantLong), topology.st_makepoint(:buyerLat, :buyerLong))""",
    nativeQuery = true
)
fun calculateDistance(
    @Param("restaurantLat") restaurantLat: Double,
    @Param("restaurantLong") restaurantLong: Double,
    @Param("buyerLat") buyerLat: Double,
    @Param("buyerLong") buyerLong: Double
): Double

我刚刚明确指定了 postgres 架构，它解决了我的问题

【讨论】：

两件事：坐标必须先表示为经度，然后是纬度。如果您必须为 PostGIS 函数指定架构，它会比字母更快地失败。您必须在用户 path 中设置 PostGIS 架构。见stackoverflow.com/a/48422325/7635569
ST_Distance 与 long-lats 将返回以度为单位的距离（这是没有意义的），而不是以米为单位，除非您将几何图形转换为地理