mysql – 在解析过程中找到非法的非几何’aswkb(…)’值

我使用了http://dev.mysql.com/tech-resources/articles/4.1/gis-with-mysql.html的教程
所以我创建了两个表,插入了一些数据,当我试图使用这样的脚本获取一些数据

SELECT
  c.cab_driver,
  ROUND(GLength(LinestringFromWKB(Linestring(AsBinary(c.cab_loc),
                                             AsBinary(a.address_loc)))))
    AS distance
FROM cab c, address a
WHERE a.address = 'Foobar street 110'
ORDER BY distance ASC LIMIT 1;

我收到一个错误：“错误代码：1367非法非几何’aswkb(c.cab_loc)’值解析过程中找到”

有什么建议？

我在这个问题上取得了一些进展,我试着跑了

SELECT 
    asbinary(c.cab_loc)
FROM usercoordinates.cab c;

我在每一行都得到NULL,但如果我使用astext,我会在每一行得到POINT(…)

最后我得到了它,也许不是最好的解决方案

SELECT
  c.cab_driver,
  Round(glength(LinestringFromWKB(Linestring(GeomFromText(astext(c.cab_loc)),GeomFromText(astext(a.address_loc)))))) AS distance
FROM cab c, address a
WHERE a.address = 'Foobar street 99'
ORDER BY distance ASC LIMIT 1;

解决方法:

SELECT c.cab_driver,
Round(glength(LinestringFromWKB(Linestring(GeomFromText(astext(c.cab_loc)),
GeomFromText(astext(a.address_loc)))))) AS distance
FROM cab c, address a
WHERE a.address = 'Foobar street 99'
ORDER BY distance ASC LIMIT 1;