In MySQL, the UPPER() function converts lowercase characters to uppercase, according to the current character set mapping (the default mapping is utf8mb4).
DBMS
Database Management Systems
How the INSTR() Function Works in MySQL
The INSTR() function returns the position of the first occurrence of a substring within a string. Basically, it does the same thing that the two-argument syntax of the LOCATE() function does (except that the order of the arguments is reversed).
How the EXPORT_SET() Function Works in MySQL
The MySQL EXPORT_SET() function returns a string that represents the bits in a number.
You have the ability to customise how the function outputs the string. The function accepts a number of arguments that allows you to do this. When you call the function, you provide the number in question, as well as arguments that determine how the results are displayed.
SQL Server Mathematical Functions (Full List)
Transact-SQL contains a number of mathematical functions that you can use with SQL Server.
The following scalar functions can be used in SQL Server 2012 and above. Most of these functions accept one or more arguments, and will return a numeric value based on the argument/s supplied.