选择包含行

Question

我有一个ROAD表，每行的每个顶点都有一行：

+---------+--------------+-------------+
| ROAD_ID | VERTEX_INDEX | MEASURE_VAL |
+---------+--------------+-------------+
|       1 |            1 |           0 |
|       1 |            2 |         1.2 |
|       1 |            3 |         2.8 |
|       1 |            4 |         4.0 |
|       1 |            5 |         4.3 |
|       1 |            6 |         6.7 |
|       1 |            7 |         7.1 |
+---------+--------------+-------------+
|       2 |            1 |           0 |
|       2 |            2 |         5.2 |
|       2 |            3 |         7.7 |
|       2 |            4 |         9.6 |
|       2 |            5 |        11.8 |
+---------+--------------+-------------+
|       3 |            1 |           0 |
|       3 |            2 |         2.4 |
|       3 |            3 |         4.9 |
+---------+--------------+-------------+

以及包含EVENT与道路部分相关的行的表格：

+----------+---------+--------------+------------+
| EVENT_ID | ROAD_ID | FROM_MEASURE | TO_MEASURE |
+----------+---------+--------------+------------+
|       01 |       1 |          2.8 |        5.9 |
|       02 |       2 |          3.0 |        5.6 |
|       03 |       3 |            0 |        2.6 |
+----------+---------+--------------+------------+

我想选择的顶点ROAD，其中MEASURE_VAL包括/包含EVENT表的FROM_MEASURE和TO_MEASURE（包括之间的顶点）：

+---------+--------------+-------------+
| ROAD_ID | VERTEX_INDEX | MEASURE_VAL |
+---------+--------------+-------------+
|       1 |            3 |         2.8 |
|       1 |            4 |         4.0 |
|       1 |            5 |         4.3 |
|       1 |            6 |         6.7 |
+---------+--------------+-------------+
|       2 |            1 |           0 |
|       2 |            2 |         5.2 |
|       2 |            3 |         7.7 |
+---------+--------------+-------------+
|       3 |            1 |           0 |
|       3 |            2 |         2.4 |
|       3 |            3 |         4.9 |
+---------+--------------+-------------+

换句话说，我想从事件和之间的ROADS位置选择顶点，如果不完全等于或，则还包括前面和/或后面的顶点（如果适用）。MEASURE_VALFROM_MEASURETO_MEASUREMEASURE_VALFROM_MEASURETO_MEASURE

再说一遍，我想选择包含事件的行部分。

我怎样才能做到这一点？

Answer 1

您可以简单地使用LAGand获取上一个和下一个度量值LEAD，并根据它们进行过滤：

select road_id, vertex_index, measure_val from (
  select
    r.road_id, r.vertex_index, r.measure_val, e.from_measure, e.to_measure,
    lag(r.measure_val, 1, r.measure_val) over 
      (partition by e.road_id order by r.vertex_index) as prev_measure_val,
    lead(r.measure_val, 1, r.measure_val) over 
      (partition by e.road_id order by r.vertex_index) as next_measure_val
  from
    road r join event e on (r.road_id = e.road_id)
) where prev_measure_val <= to_measure and next_measure_val >= from_measure;