Mysql57 geography srid

[hrach]

No description provided.

[coveralls]

Coverage increased (+0.005%) to 99.123% when pulling c703730 on tripomatic:mysql57_geography_srid into 501df61 on creof:develop.

[hrach]

Ok, here we are, the issue is - MySQL 5.7 checks for the same SRID for the values. If they are not, it throws "General error: 3033 Binary geometry function mbrcontains given two geometries of different srids: 4326 and 0, which should have been identical.". MySQL 5.6 ignores the second parameter and inserts the geometry with srid 0.

Currently, Travis does not support MySQL 5.7, so I rather not to write sh scripts to somehow reinstall the database to properly test this. Right now, we are deploying this into production.

[sadortun]

Hi @hrach i think testing 5.7 is a good idea, not only for this PR, but for the entire project.

We should implement #157 before merging this PR

[djlambert]

The issue I see with this is there's no way to change the SRID from the default. At the very least It should use the SRID if set in the object, then fallback to default.

[sadortun]

4326 magic number : spherical Mercator

http://spatialreference.org/ref/epsg/4326/

[hrach]

@djlambert well, I try to dig a little bit, but I wasn't able to get the while concept how the interface and methods work. In the current method I'm just chainging the raw sql, there is no object, as for Postgre. Moreover, MySQL 5.7 doesn't seems to work with different srid in one column.

We may to add some configuration for the column, but I'm not sure where to get It. One possibility is not to solve it, ale let people override the constant and use LSB.

[yurtesen]

Is there any news about if SRID's will be supported for MySQL or not?

[holtkamp]

For PostgreSQL when writing a Geography to the database the SRID can be indicated using Extended WKT (EWKT), for example: SRID=4326;POINT(x y)

Unfortunately MySQL does not support EWKT

As @hrach suggested, the simplest approach seems to introduce a public static property which can be set by the user during ORM configuration:

\CrEOF\Spatial\DBAL\Platform\MySql::$srid = 4326;

And then read when persisting a GeographyType:

    public function convertToDatabaseValueSQL(AbstractSpatialType $type, $sqlExpr)
    {
        return $type instanceof GeographyType && is_int(self::$srid)
            ? sprintf('ST_GeomFromText(%s, %d)', $sqlExpr, self::$srid)
            : sprintf('ST_GeomFromText(%s)', $sqlExpr);
    }

Adopted this in the following branch: https://github.com/holtkamp/doctrine2-spatial/blob/mysql-80-support/lib/CrEOF/Spatial/DBAL/Platform/MySql.php, available for merge via #196

Sidenote: this rather naive approach does prevent the use of different SRIDs in the same database...