ABSTRACT
Three are many functions available in Oracle SQL, T-SQL and MySQL. Three function groups are described in this chapters: common number functions, common string functions and common date time functions. The chapter lists major functions in tables for Oracle SQL, T-SQL and MySQL first, then all the functions are used with sample data. The readers will see the function output from Oracle SQL, T-SQL and MySQL. By the end of the chapter readers will be able to use number functions, string functions and date time functions.
