Support for OGR SQL type cast and field name alias

[tamas]

These changes will support to change the name and the type of the fields in the results of the OGR SQL query. A patch will be attached with the implementation details.

I suspect gdal/ogr/ogr_sql.dox still needs to be updated to reflect this change.

[tamas]

The corresponding RFC can be found here: http://trac.osgeo.org/gdal/wiki/rfc21_ogrsqlcast

[tamas]

Update the patch to reflect the RFC changes

[tamas]

Applied in r13721

[warmerdam]

I have added a minimal sort of sql cast operator test in ogr_sql_test.py as r13888 in trunk.

[tamas]

I've modified ogr_sql.dox to reflect the changes r13889

[dylan]

I have noticed that it is not possible to use the 'AS' construct within an SQL argument to ogr2ogr.

Here is the incantation: ogr2ogr -t_srs '+proj=latlong +datum=WGS84' \ -f GPX -dsco GPX_USE_EXTENSIONS=YES \ veg_points.gpx veg_points.shp \ -sql "SELECT cat AS name FROM veg_points"

The data involved is attached.

[dylan]

test data

[dylan]

test data

[dylan]

test data

[dylan]

test data

[tamas]

ogr2ogr result

[tamas]

I've tried this using the trunk on Windows but it have been working the result attached. Might it be a platform dependent issue?

Tamas

Replying to dylan:

I have noticed that it is not possible to use the 'AS' construct within an SQL argument to ogr2ogr.

Here is the incantation: ogr2ogr -t_srs '+proj=latlong +datum=WGS84' \ -f GPX -dsco GPX_USE_EXTENSIONS=YES \ veg_points.gpx veg_points.shp \ -sql "SELECT cat AS name FROM veg_points"

The data involved is attached.

[dylan]

It looks like it works for Tamas on Windows. I am using Linux x86, and here is the output from svn info:

URL: http://svn.osgeo.org/gdal/branches/1.5
Repository Root: http://svn.osgeo.org/gdal
Repository UUID: f0d54148-0727-0410-94bb-9a71ac55c965

Am I not using the latest and greatest GDAL?

Replying to tamas:

I've tried this using the trunk on Windows but it have been working the result attached. Might it be a platform dependent issue?

Tamas

Replying to dylan:

I have noticed that it is not possible to use the 'AS' construct within an SQL argument to ogr2ogr.

Here is the incantation: ogr2ogr -t_srs '+proj=latlong +datum=WGS84' \ -f GPX -dsco GPX_USE_EXTENSIONS=YES \ veg_points.gpx veg_points.shp \ -sql "SELECT cat AS name FROM veg_points"

The data involved is attached.

[dylan]

Apologies- I was using the 1.5 stable branch. I can confirm the this functionality works on x86 Linux with GDAL-trunk. Thanks.

[tamas]

I believe this ticket can be closed for now.