[mapserver-users] RFC 74 "DBINCLUDE"

[Stephen Woodbridge]

On 6/12/2013 5:20 PM, Robert Hollingsworth wrote:
> I'm looking at implementing RFC 74 "Includes from non-file connections,"
> i.e., using a database query to bring in a section of mapfile, as an
> alternative to the INCLUDE /filename/ that's in there already.
>
> Some interesting and powerful capabilities hinted at in the RFC, such as,
> "A common use case is providing a custom classed layer for an individual."
> and
> "Another common case is dynamically classifying a layer as the data
> changes. With SQL, a text string can be calculated on the fly from the
> data itself, by looking at the DISTINCT values of a dataset to generate
> the classes that will be used to display that data."
> There have been some threads in this space that lead me to believe this
> feature could be a good thing to have around.  It might serve as the
> foundation for providing for non-database sources for mapfile includes
> in the future.  I'd invite interested parties to look at the RFC and
> comment back with possible additional use cases, to see how well the
> prescribed mapfile syntax for this supports those uses.

Hi Robert,

Here are some thoughts on this:

1. We may want to be able to pass additional mapserver variable into the 
SQL. For example the BBOX of the request classification can be limited 
to that extent. SCALE of the map request so different tables can be 
configured based on the SCALE.

2. If I need to perform a complex join and other complex SQL can I do 
that using the DATA statement like I can now as a sub-select?

3. Can these be embedded in a regular INCLUDE and vica versa?

4. How would we pass USER into the request? via normal mapserver 
variable substitution? via the webserver authenticated user?

You might want to add these to the RFC, it is common to include a 
section in the RFC to track ideas that are outside the scope of the 
project and comment on why.

One of the things that has been asked for in the past is "named styles" 
ie: reuseable named snippets, like highways, toll-roads, major-roads, 
minor-roads, streets, or points of interest by "type", etc. It seems 
like this would allow for that and an example demonstrating this would 
be ideal.

-Steve