In the first chapter, we gave you a brief taste of what PostGIS is and what are the basic spatial types it supports. In this chapter we'll demonstrate how to create these spatial types and how to create spatial database columns. We'll introduce the concept of typmod that allows constraining geometry and geography types based on declarative column type definition such as geom geometry(LineString,4326)
Stay tuned for our next book pgRouting: A Practical Guide published by Locate Press due out in hard-copy 4th quarter 2017. Content is now feature complete and can purchase e-Book draft and get final when goes to print.
© Leo Hsu and Regina Obe 2014