I compared scalar SQL functions in 5 different RDBMS: **PostgreSQL**, **MySQL**, **Oracle**, **SQL Server** and **SQLite**, and also in the [ANSI SQL Standard](https://en.wikipedia.org/wiki/SQL#Standardization_history). There are large differences among different RDBMS, and I propose to reduce them a little bit. The ANSI SQL Standard defines the `MOD(x, y)` function which returns division remainder. It is already implemented in PostgreSQL, MySQL, and Oracle. Currently, SQL Server and SQLite implement only modulo operator: `x % y`. For more information about comparing implementations of the scalar functions, click here: [https://github.com/iwis/SQL-notes/blob/master/Functions.txt](https://github.com/iwis/SQL-notes/blob/master/Functions.txt)