I have create a table (municipal_border), in MySQL 5.5, that holds some boundaries.
CREATE TABLE `municipal_border` (
`boundary` polygon NOT NULL,
`municipalID` int(10) NOT NULL,
) ENGINE=InnoDB
The field municipalID is not unique.
I'm using the code below to test if a point belongs into a polygon.
set @r = (SELECT municipal_border.boundary FROM municipal_border WHERE municipalID=9001);
set @p = GeomFromText('POINT(24.1621 41.0548)');
select if(contains(@r, @p), 'yes', 'no');
The first statement set @r = ... returns just one row and I selected it specially for testing. It works just great.
What I want to do is to search the whole table (erasing, in other words, the WHERE part from the SQL question) and find in which polygon the point is in.
After a night sleep I found the following solution.
set @p = GeomFromText('POINT(23.923739342824817 38.224714465253733)');
select municipalID FROM ecovis.municipal_border
where ST_Contains(municipal_border.boundary, @p);
It is working for MySQL 5.6.1 where ST_ prefix function have been implemented. Although I haven't any measurments from a classical approach (x-ray algorithm) I believe that is quite fast. It needs 0.17 seconds to locate a point in 2700 polygons with some polygons having well more than 1,500 points.