Follow this step-by-step guide to install PostgreSQL, load data, connect to a database, and execute SQL queries including table joins PostgreSQL is an open-source, object-relational (also called ...

-- 1. Select the code which uses an outer join correctly. -- 3. Select out of following the code which uses a JOIN to show a list of all the departments and number of employed teachers SELECT ...

This is essentially a container storing organised data electronically, usually controlled by something called a database management system (DBMS for short). These can store more data (and are more ...

PL/SQL stands for Procedural Language extension of SQL. PL/SQL is a combination of SQL along with the procedural features of programming languages. It was developed by Oracle Corporation in the early ...