[Mapserver-users] Re: Mapserver/Mapscript and MySQL 4

[pkishor_98]

--- In mapserver-users at yahoogroups.com, Matthew Smith <matt at k...> wrote:
> Hi All
> 
> I have an application where I need to:
> * Create a layer from a shapefile
> * Create an overlying layer of data from a database query.
> 
> I am using MySQL 4.0.x, so MyGIS mentioned in the Wiki is out, although 
> it would have been the preferred solution.

why would it have been the preferred solution? The reason I ask -- is there 
something to be achieved by putting your spatial data into a database? is there 
something you can do with it in the db that you can't do with it as shapefiles? 
Essentially, I ask this of myself -- is there any advantage to a specific way, or am I 
going to do it that way only because it is available...

That said...

> 
> I guess that means that I'll have to generate everything with Mapscript 
> instead - no real hardship since I do just about everything else in Perl.

yup, that is how I would do it.

> 
> Can anyone point me at an example similar to what I'm trying to achieve 
> (one layer from a shapefile, one from DBI)?
> 
> Is using two layer sources like this a reasonable approach, or should I 
> just dump all my shapefiles into MySQL?  I've considered this but feel 
> that it could be a little awkward as this version of MySQL does not 
> appear to have native GIS support - my current data structures can 
> already hold point data, but my "bottom layer" is all polygons.
> 


two layer sources sounds very reasonable... let the polys be a shapefile, and let the 
points be in MySQL. Grab the required points using DBI/DBD, generate a layer with 
those points as the features...

in fact, does your point data change? does it need to be stored in a database? 
depending on the size of the dataset (number of points), and "stability" of those 
points, converting them all to a shapefile before doing anything might make the 
operation even faster... you avoid the DBI/DBD overhead.

Anyway, your proposed solution seems perfectly reasonable.