Oracle PL/SQL Programming, 5th Edition

String Function Quick Reference

As I have already pointed out, 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. The following list gives you an idea of the power at your disposal and will be enough to remind you of syntax. For complete details on a given function, see Oracle’s SQL Reference manual.

ASCII(single_character)

Returns the NUMBER code that represents the specified character in the database character set.

ASCIISTR(string1)

Takes a string in any character set and converts it into a string of ASCII characters. Any non-ASCII characters are represented using the form \XXXX, where XXXX represents the Unicode value for the character.

Note

For information on Unicode, including the underlying bytecodes used to represent characters in the Unicode character set, visit http://unicode.org.

CHR(code_location)

Returns a VARCHAR2 character (length 1) that corresponds to the location in the collating sequence provided as a parameter. This is the reverse of ASCII. One variation is useful when working with national character set data:

CHR(code_location USING NCHAR_CS)

Returns an NVARCHAR2 character from the national character set.

COMPOSE(string1)

Takes a Unicode string as input and returns that string in its fully normalized form. For example, you can use the unnormalized representation ‘a\0303’ to specify the character ‘a’ with a “~” on top (i.e., ã). COMPOSE('a\0303') will then ...