[gdal-dev] OGR and database filter on spatial extent

[Brent Fraser]

Frank,

 > Brent,
> 
> Any time you provide your own SQL it will be executed unaltered.  The
> spatial and attribute filters are only automatically built into the
> select statement when the select statement is constructed internally
> by OGR.
> 
> OGR makes *no attempt at all* to interprete provided SQL (via ExecuteSQL()
> or <SrcSQL>.  So it has no idea what tables it relates to or how any
> restrictions could be added.


I guess that's technically true, but ogr (likely the VRT parser) gives an error when I try to construct my own spatial filter:

<SrcSQL>SELECT * FROM alta83_v1 WHERE BOT_LONG > -114 AND BOT_LONG < -113 AND BOT_LAT > 51 AND BOT_LAT < 52</SrcSQL>

ERROR 1: Line 4: Didn't find expected '=' for value of attribute 'AND'.

I expect it doesn't like the ">".  Quoting the SQL and bracketing the where clause portion doesn't help.   Perhaps there's an escape sequence I could use?

And is there point in constructing a view with columns of WKT geometry, XMIN, YMIN, XMAX and YMAX to see if the ODBC driver would take advantage of those?

Thanks!
Brent