We have already seen a little preview of ogr2ogr exporting the data when we made sure that our KML import had actually brought in the proper data. This time we'll expand on the subject a bit and also export a few more formats, to give you an idea of how sound a tool ogr2ogr is.

In order to get some information on the tool, simply type the following in the console:

ogr2ogr

Alternatively, if you would like to get some more descriptive info, visit http://www.gdal.org/ogr2ogr.html.

You could also type the following:

ogr2ogr -long-usage

The nice thing about ogr2ogr is that the tool is very flexible and offers some options that allow us to export exactly what we are after. You can specify what data you would like to select by specifying the columns in a -select parameter. -where parameter lets you specify the filtering for your dataset in case you want to output only a subset of data. Should you require more sophisticated output preparation logic, you can use an -sql parameter.

This is obviously not all there is. The usual gdal/ogr2ogr parameters are available too. You can reproject the data on the fly using the -t_srs parameter, and if, for some reason, the SRS of your data has not been clearly defined, you can use -s_srs to instruct ogr2ogr what the source coordinate system is for the dataset being processed.

There are obviously advanced options too. Should you wish to clip your dataset to a specified bounding box, polygon, or coordinate system, have a look at the -clipsrc, and -clipdst parameters, and their variations.

The last important parameter to know is -dsco-dataset creation options. It accepts values in the form of NAME=VALUE. When you want to pass more than one option this way, simply repeat the parameter. The actual dataset creation options depend on the format used, so it is advised that you consult the appropriate format information pages available via the ogr2pgr website.