Query Vector Data Using a WHERE Clause – ogrinfo

The following is an excerpt from the book: Geospatial Power Tools – Open Source GDAL/OGR Command Line Tools by Tyler Mitchell.  The book is a comprehensive manual as well as a guide to typical data processing workflows, such as the following short sample…

Use SQL Query Syntax with ogrinfo

Use a SQL-style -where clause option to return only the features that meet the expression. In this case, only return the populated places features that meet the criteria of having NAME = ’Shanghai’:

$ ogrinfo 10m_cultural ne_10m_populated_places -where "NAME = 'Shanghai'"

... 
Feature Count: 1 Extent: (-179.589979, -89.982894) - (179.383304, 82.483323) 
... 
OGRFeature(ne_10m_populated_places):6282
 SCALERANK (Integer) = 1 
 NATSCALE (Integer) = 300 
 LABELRANK (Integer) = 1 
 FEATURECLA (String) = Admin-1 capital 
 NAME (String) = Shanghai
... 
 CITYALT (String) = (null) 
 popDiff (Integer) = 1 
 popPerc (Real) = 1.00000000000 
 ls_gross (Integer) = 0 
 POINT (121.434558819820154 31.218398311228327)

Building on the above, you can also query across all available layers, using the -al option and removing the specific layer name. Keep the same -where syntax and it will try to use it on each layer. In cases where a layer does not have the specific attribute, it will tell you, but will continue to process the other layers:

   ERROR 1: 'NAME' not recognised as an available field.

NOTE: More recent versions of ogrinfo appear to not support this and will likely give FAILURE messages instead.

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Geospatial Power Tools is 350 pages long – 100 of those pages cover these kinds of workflow topic examples.  Each copy includes a complete (edited!) set of the GDAL/OGR command line documentation as well as the following topics/examples:

Workflow Table of Contents

1. Report Raster Information – gdalinfo 23
2. Web Services – Retrieving Rasters (WMS) 29
3. Report Vector Information – ogrinfo 35
4. Web Services – Retrieving Vectors (WFS) 45
5. Translate Rasters – gdal_translate 49
6. Translate Vectors – ogr2ogr 63
7. Transform Rasters – gdalwarp 71
8. Create Raster Overviews – gdaladdo 75
9. Create Tile Map Structure – gdal2tiles 79
10. MapServer Raster Tileindex – gdaltindex 85
11. MapServer Vector Tileindex – ogrtindex 89
12. Virtual Raster Format – gdalbuildvrt 93
13. Virtual Vector Format – ogr2vrt 97
14. Raster Mosaics – gdal_merge 107