SQL Server Central has a "Stairway to T-SQL" series that starts off with some light history and then has two fairly decent chapters diving into the mathematics

SQL Server Central has a "Stairway to T-SQL" series that starts off with some light history and then has two fairly decent chapters diving into the mathematics of SQL. It's not intensive by any means, but more than most other resources (and even some textbooks I've read). [0]: https://www.sqlservercentral.com/stairways/stairway-to-t-sql-dml https://www.sqlservercentral.com/stairways/stairway-to-t-sql...