COMPOSE takes as its argument a string, or an expression that resolves to a string, in any datatype, and returns a Unicode string in its fully normalized form in the same character set as the input.
char can be any of the datatypes
NCLOB. For example, an
o code point qualified by an umlaut code point will be returned as the o-umlaut code point.
NCLOB values are supported through implicit conversion. If
char is a character LOB value, it is converted to a
VARCHAR value before the
COMPOSE operation. The operation will fail if the size of the LOB value exceeds the supported length of the
VARCHAR in the particular development environment.
See Also:Oracle Database Globalization Support Guide for information on Unicode character sets and character semantics
The following example returns the o-umlaut code point:
SELECT COMPOSE ( 'o' || UNISTR('\0308') ) FROM DUAL; CO -- ö