使用GeomFromText('POINT(1 1)')转换lat / lng对并插入另一列

时间:2011-08-18 22:54:52

标签: mysql

在我之前的问题Search for range Latitude/Longitude coordinates我的解决方案是创建下表。

mysql> select * from spatial_table where MBRContains(GeomFromText('LINESTRING(9 9, 11 11)'), my_spots);
+------+---------------------------------+
| id   | my_spots    | my_polygons       |
+------+-------------+-------------------+
|    1 |  $@      $@     $@      $@      |
+------+-------------+-------------------+

现在我需要将下表中的现有lat / lng对转换并移动到spatial_table。我将如何构建我的查询以实现此目的?我目前正在使用以下查询来插入。

mysql> insert into spatial_table values (1, GeomFromText('POINT(1 1)'), GeomFromText('POLYGON((1 1, 2 2, 0 2, 1 1))'));
Query OK, 1 row affected (0.00 sec)

mysql> insert into spatial_table values (1, GeomFromText('POINT(10 10)'), GeomFromText('POLYGON((10 10, 20 20, 0 20, 10 10))') );
Query OK, 1 row affected (0.00 sec)

现有表格:

+-------------+---------+--------+-----------+----- ------+-------------+--------------+
| location_id | country | region |  city     | latitude   | longitude   |     name     |
+=============|=========|========|===========|============|=============|==============|
|   316625    |   US    |   CA   | Santa Cruz|  37.044799 | -122.102096 |  Rio Theatre |
+-------------+---------+--------+-----------+------------+-------------+--------------+    

2 个答案:

答案 0 :(得分:8)

这是成功的秘诀:) 我原来的表:

mysql> describe gls;
+-------------+--------------+------+-----+---------+-------+
| Field       | Type         | Null | Key | Default | Extra |
+-------------+--------------+------+-----+---------+-------+
| location_id | int(255)     | NO   | PRI | 0       |       |
| country     | varchar(255) | NO   |     |         |       |
| region      | varchar(255) | NO   |     |         |       |
| city        | varchar(255) | NO   |     |         |       |
| latitude    | float(13,10) | NO   |     |         |       |
| longitude   | float(13,10) | NO   |     |         |       |
+-------------+--------------+------+-----+---------+-------+
8 rows in set (0.00 sec)

第1步:添加新的POINT列

mysql> alter table gls add my_point point;
Query OK, 247748 rows affected (4.77 sec)
Records: 247748  Duplicates: 0  Warnings: 0

步骤2:使用lat / lng字段中的值更新my_point。

UPDATE gls SET my_point = PointFromText(CONCAT('POINT(',gls.longitude,' ',gls.latitude,')'));

第3步:检查

mysql> select aswkt(my_point) from gls where city='Santa Cruz';
+--------------------------------------+
| aswkt(my_point)                      |
+--------------------------------------+
| POINT(-122.1020965576 37.0447998047) |
| POINT(-66.25 -12.2833003998)         |
| POINT(-2.3499999046 42.6666984558)   |
+--------------------------------------+

答案 1 :(得分:2)

假设你有一张这样的表:

mysql> select * from spatial_table;
+------+---------------------------+-----------------------------------------------------------------------------------+---------+--------+
| id   | my_spots                  | my_polygons                                                                       | lon     | lat    |
+------+---------------------------+-----------------------------------------------------------------------------------+---------+--------+
|    1 |              ??      ??   |                    ??      ??       @       @               @      ??      ??     | -122.11 | -37.11 |
|    1 |              $@      $@ |                    $@      $@      4@      4@              4@      $@      $@ | -122.11 | -37.11 |
+------+---------------------------+-----------------------------------------------------------------------------------+---------+--------+
2 rows in set (0.00 sec)

如果要创建具有lon lat值的几何列(仅作为点,对于其他类型的几何,语法略有不同),您可以这样做:

mysql> alter table spatial_table add column (go_slugs geometry);

这是几何类型,如果它是所有单个位置,则可以使列类型为point。然后只需更新新列:

mysql> update spatial_table set go_slugs = point(lon, lat);

使用aswkt函数获取人类可读数据以确认这是正确的:

mysql> select aswkt(go_slugs) from spatial_table;
+-----------------------------------------------+
| aswkt(go_slugs)                               |
+-----------------------------------------------+
| POINT(-122.11000061035156 -37.11000061035156) |
| POINT(-122.11000061035156 -37.11000061035156) |
| POINT(-123.4000015258789 37.79999923706055)   |
+-----------------------------------------------+
3 rows in set (0.00 sec)