PostGIS in Action, Third Edition

Appendix C. SQL primer

PostgreSQL supports almost the whole ANSI SQL 92, 1999 standard logic, as well as many of the SQL:2003, SQL:2006, and SQL:2008 constructs, and a fair amount of the SQL:2011 and SQL:2016 constructs. PostgreSQL is probably the most ANSI-SQL-compliant database you will find on the planet. As such, if you’ve used other relational databases, you probably already know how to use PostgreSQL. In this appendix, we’ll cover many of the ANSI-SQL constructs as well as some PostgreSQL-specific SQL language extensions. Because we’ll remain largely focused on standard functionality, the content in this appendix is also applicable to other standards-compliant relational databases. The less-standard features that PostgreSQL offers will ...