Oracle PL/SQL Programming, Third Edition

String Functions

PL/SQL provides a rich set of string functions that allow you to get information about strings and modify the contents of those strings in very high-level, powerful ways. Table 8-3 shows the string functions covered in detail in this section. The remaining functions are specific to Oracle’s National Language Support (NLS) and Trusted Oracle features. National Language Support functions are covered later in this chapter in Section 8.5.

Table 8-3. String functions

Name	Description
ASCII	Returns the ASCII code of a character.
ASCIISTR	Converts a string to a string of ASCII characters.
CHR	Returns the character associated with the specified collating code.
COMPOSE	Takes a Unicode string and returns it in a fully normalized form.
CONCAT	Concatenates two strings into one.
DECOMPOSE	Takes a Unicode string and returns it in with any precomposed characters decomposed into separate elements.
GREATEST	Returns the string that would come last (if sorted alphabetically).
INITCAP	Sets the first letter of each word to uppercase. All other letters are set to lowercase.
INSTR, INSTRB, INSTRC, INSTR2, INSTR4	Returns the location in a string of the specified substring.
LEAST	Returns the string that would come first (if sorted alphabetically).
LENGTH, LENGTHB, LENGTHC, LENGTH2, LENGTH4	Returns the length of a string.
LOWER	Converts all letters to lowercase.
LPAD	Pads a string on the left with the specified characters.