CONCAT : join two or more values together.
SUBSTR : used to extract the string of specific length.
LENGTH : return the length of the string in numerical value.
INSTR : find the exact numeric position of a specified character.
LPAD : padding of the left-side character value for right-justified value.
RPAD : padding of right-side character value for left-justified value.
TRIM : remove all the defined character from the beginning, end or both beginning and end.
REPLACE : replace a specific sequence of character with other sequences of character.
