Tag Archives: SQL

Find and select duplicate values in your vector attribute table

Posted on May 4, 2012 by

Suppose you have a vector layer in your GRASS GIS database and you want to find all duplicate values in one of the columns of the attribute table of that layer? If you are using SQLite or PostgreSQL as the … Continue reading →

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Concatenate in SQLite

Posted on September 14, 2011 by

I wrote before on using concatenate in OpenOffice / LibreOffice and how this alternatively can be done in R using the paste function. You can do the same in SQLite using a query too.

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Select random sample from SQLite table

Posted on April 16, 2011 by

I came across this post by underdark about how to select a random sample from a table in PostgreSQL. You can achieve the same (selecting 1000 random features from a table) in SQLite using something like below:

Posted in Data handling, GIS, Spatialite, SQLite | Tagged , , , , | Leave a comment

Finding and removing carriage returns in your SQLite table

Posted on January 13, 2011 by

The problem with copy data from e.g., an excel or calc sheet into an SQLite database (or any database I reckon) is that the data you copy might include an carriage return. I found this out the hard way after … Continue reading →

Posted in Data handling, GRASS GIS, SQLite | Tagged , , , | 2 Comments