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I have a shapefile with several polygons. I would like to clip a series of rasters but only use a single feature from the shapefile feature class. I am using gdal_warp. There is an option to query the feature class using sql by using the -csql option in the tool.

Can any one provide an example of how this looks in the command line?

Perhaps this is only used when connecting to a spatially enabled database as a datasource?

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Here's my answer:

Although I don't completely understand how layers work in gdal I have found they are almost always the file name without path or extension. For example: "C:/Folder/AllRiverMileSegments.shp" would be loaded as the layer "AllRiverMileSegments".

Writing a SQL statement for gdalwarp uses this layer as the table name and calls columns in the attribute table as columns of that table. In my above shapefile I want to query river mile segments. In my attribute table I have have a column called "RiverMile" that I will use to query river mile segments from the feature class. The section of gdalwarp that calls for this statement will look like this:

-csql "SELECT * FROM AllRiverSegments WHERE RiverMile = $RIVERMILE"

Where $RIVERMILE is the river mile number I want to query.

Thanks to MerseyViking for getting me started here.

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