ST_MakeLine 的字母数字输出

Question

我正在尝试将纬度/经度转换为线串。基本上，将 lat 和 lon 列分组，创建一个点，然后创建一个线串。

表：

+------------+----------+-----------+------------+---------+--------+
|  link_id   | seq_num  |    lat    |    lon     | z_coord | zlevel |
+------------+----------+-----------+------------+---------+--------+
| "16777220" | "0"      | "4129098" | "-7192948" |         |      0 |
| "16777220" | "999999" | "4129134" | "-7192950" |         |      0 |
| "16777222" | "0"      | "4128989" | "-7193030" |         |      0 |
| "16777222" | "1"      | "4128975" | "-7193016" |         |      0 |
| "16777222" | "2"      | "4128940" | "-7193001" |         |      0 |
| "16777222" | "3"      | "4128917" | "-7192998" |         |      0 |
| "16777222" | "4"      | "4128911" | "-7193002" |         |      0 |
+------------+----------+-----------+------------+---------+--------+

我的代码：

select link_id, ST_SetSRID(ST_MakeLine(ST_MakePoint((lon::double precision / 100000), (lat::double precision / 100000))),4326) as geometry
from public.rdf_link_geometry
group by link_id
limit 50

几何输出列示例： “0102000020E6100000020000004F92AE997CFB51C021E527D53EA54440736891ED7CFB51C021020EA14AA54440”

^^ 这是什么？它是如何以这种方式格式化的？我期待一个线串，像

geometry
7.123 50.123,7.321 50.321
7.321 50.321,7.321 50.321

link_id 的数据格式是 bingint，对于几何来说它是几何

解决方案：

select link_id, ST_AsText(ST_SetSRID(ST_MakeLine(ST_MakePoint(
(lon::double precision / 100000), (lat::double precision / 100000))),4326)) as geometry
from public.rdf_link_geometry
group by link_id
limit 50

Answer 1

输出是geometry，您可以使用st_asText将其显示为文本

select st_asText('0102000020E6100000020000004F92AE997CFB51C021E527D53EA54440736891ED7CFB51C021020EA14AA54440');
                    st_astext
--------------------------------------------------
 LINESTRING(-71.92948 41.29098,-71.9295 41.29134)

话虽如此，如果你有超过 2 个点，你可以命令他们创建一个有意义的线：

select st_makeline(geom ORDER BY seqID) from tbl;