[mapserver-users] MS-SQL / OGR Query Length Problem

[Ben Madin]

G'day all,

In a nightmare scenario, to provide maximum flexibility for a client I  
am using php/mapscript (4.8) to generate and display mapfiles (not the  
nightmare bit) using OGR to connect to a MS-SQL Server (2003)  
Database... I would just like to say here the fact that this works is  
nothing short of brilliant.

We can't use the mapserv.exe as they have a hang-up about security  
risks, but we can use php. Go figure! The real nightmare is in fact  
that we can get this all to work on the client's server, but can't  
work out how to do it locally (using ms4w and MSDE 2000), and so have  
very limited debugging information coming back to us - what we have  
been able to work out is that if we have a working file with multiple  
layers, the layers with short queries will work OK, but getting to a  
layer based on a long query breaks it.

This was allowing us to create really great maps of all sorts of stuff  
(the database handles multiple projects), except when we made a  
seriously impressive SQL query (which returned exactly what we thought  
was right) the whole process died.

Roughly, it would seem that between about 1600 and 1700 characters of  
SQL kills the process. It can be very simple query (just straight  
data), and shorter more complex queries work. cutting excess white  
space can make a difference.

So, is it a limit of OGR or ODBC that I can't find any reference to. I  
can't see that it is a problem with SQL Server, and I have had (I  
think) longer SQL queries working using postgis...

My question is, does anyone know where this might be breaking /  
happening? (bonus points if you know whether it is a configuration  
setting that we could tune!)

cheers

Ben


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Ben Madin
REMOTE INFORMATION

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