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 ...

1970 − Dr. Edgar F. "Ted" Codd of IBM is known as the father of relational databases. He described a relational model for databases. 1974 − Structured Query Language appeared. 1978 − IBM worked to ...

Community driven content discussing all aspects of software development from DevOps to design patterns. The SQL specification defines four transaction isolation levels, although a fifth transaction ...