MySQL5.6将对空间字段geometry运算全面支持

还是做数据库迁移。

还是从MSSQL迁移到MySQL,数据迁移过去了，最大的问题就在于MySQL不支持空间运算。最初我的打算是用MySQL连接C，然后用C去连接Postgres，然后由Postgres的Postgis插件运算后，返回结果。纠结了两天，堆了一天代码失败，返回始终为NULL，万般无奈下，翻看MySQL文档，查到在5.6中即将支持精确的空间运算，十分高兴，立马下载其测试版，试用，果然好用。纠结结束，分享链接：

http://dev.mysql.com/doc/refman/5.6/en/functions-for-testing-spatial-relations-between-geometric-objects.html

注意其中的NOTE，亮点在于：

Note

MySQL originally implemented these functions such that they used object bounding rectangles and returned the same result as the corresponding MBR-based functions. As of MySQL 5.6.1, corresponding versions are available that use precise object shapes. These versions are named with an ST_ prefix. For example, Contains() uses object bounding rectangles, whereas ST_Contains() uses object shapes.

As of MySQL 5.6.1, there are also ST_ aliases for existing spatial functions that were already exact. For example,ST_IsEmpty() is an alias for IsEmpty()