CONCAT - Concatenates two or more expressions together
CONCAT_WS - Concatenates two or more expressions together and adds a separator between them
INSTR - Returns the position of the first occurrence of a string in another string
LEFT - Extracts a substring from a string (starting from left)
LENGTH - Returns the length of the specified string (in bytes)
LOWER - Converts a string to lower-case
LTRIM - Removes leading spaces from a string
REPEAT - Repeats a string a specified number of times
REPLACE - Replaces all occurrences of a specified string
RIGHT - Extracts a substring from a string (starting from right)
RTRIM - Removes trailing spaces from a string
SUBSTR - Extracts a substring from a string (starting at any position)
TRIM - Removes leading and trailing spaces from a string
UPPER - Converts a string to upper-case
DIV - Used for integer division
MOD - Returns the remainder of n divided by m
RAND - Returns a random number or a random number within a range
ROUND - Returns a number rounded to a certain number of decimal places
TRUNCATE - Returns a number truncated to a certain number of decimal places
ADDDATE - Returns a date after a certain time/date interval has been added
CURRENT_DATE - Returns the current date
CURRENT_TIME - Returns the current time
CURRENT_TIMESTAMP - Returns the current date and time
DATEDIFF - Returns the difference in days between two date values
DATE_ADD - Returns a date after a certain time/date interval has been added
DAYNAME - Returns the weekday name for a date
DAYOFMONTH - Returns the day portion of a date value
DAYOFWEEK - Returns the weekday index for a date value
DAYOFYEAR - Returns the day of the year for a date value
EXTRACT - Extracts parts from a date
NOW - Returns the current date and time
WEEKOFYEAR - Returns the week of the year for a date value
CASE - Lets you evaluate conditions and return a value when the first condition is met
CAST - Converts a value from one datatype to another datatype
COALESCE - Returns the first non-null expression in a list
IF - Returns one value if a condition is TRUE, or another value if a condition is FALSE