Day 1: Relations, CRUD, and Joins
While we won’t assume that you’re a relational database expert, we do assume that you’ve confronted a database or two in the past. If so, odds are good that the database was relational. We’ll start with creating our own schemas and populating them. Then we’ll take a look at querying for values and finally explore what makes relational databases so special: the table join.
Like most databases you’ll read about, Postgres provides a back-end server that does all of the work and a command-line shell to connect to the running server. The server communicates through port 5432 by default, which you can connect to the shell using the psql command. Let’s connect to our 7dbs schema now:
| | $ psql 7dbs |
PostgreSQL ...
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