Oracle character function lower () upper () length () substr (char, m, n)

Oracle character function lower () upper () length () substr (char, m, n) I. Character function: lower case function: lower (); usage: for example, all the names of a table are in lowercase: select lower (t. ename) from scott. emp t capital function: upper (); usage: for example, if all the names of a table are capitalized: select upper (t. ename) from scott. emp t length function: length (); usage: for example, to extract all the names of a table with a length of 5 Characters: select t. ename from scott. emp t where length (t. ename) = 5 Note: length refers to the length of a string. For example, if "China" is 2 "AB", it is also 2 truncated string: substr (char, m, n) usage: for example, select substr (t. ename, 1, 3) from scott. emp t Comprehensive Usage: displays the names of all employees in uppercase. select upper (substr (t. ename, 1, 1) | lower (substr (t. ename, 2, length (t. ename)-1) from scott. emp t 2. select initcap (ename) from scott. emp;