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 ...

It is a SQL practice repository covering basics to advanced topics. It includes exercises on SELECT statements, WHERE clauses, GROUP BY, JOINS, window functions (OVER(), PARTITION BY), ROW_NUMBER(), ...