MySQL

Functions

Functions are called to perform a calculation and return a value. Functions must be invoked with no space between the function name and the parenthesis following it:

NOW()                    Correct
NOW ()                   Incorrect

If you pass multiple arguments to a function, arguments must be separated by commas. Spaces are allowed around function arguments:

CONCAT("abc","def")      This is okay
CONCAT( "abc" , "def")  This is okay, too

Comparison Functions

• GREATEST( expr1,expr2,… )

  Returns the largest argument, where "largest" is defined according to the following rules:

  • If the function is called in an integer context or all the arguments are integers, the arguments are compared as integers.

  • If the function is called in a floating-point context or all the arguments ...