Oracle® Database SQL Language Reference 11g Release 2 (11.2) Part Number E17118-04 |
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TRANSLATE
returns expr
with all occurrences of each character in from_string
replaced by its corresponding character in to_string
. Characters in expr
that are not in from_string
are not replaced. The argument from_string
can contain more characters than to_string
. In this case, the extra characters at the end of from_string
have no corresponding characters in to_string
. If these extra characters appear in expr
, then they are removed from the return value.
If a character appears multiple times in from_string
, then the to_string
mapping corresponding to the first occurrence is used.
You cannot use an empty string for to_string
to remove all characters in from_string
from the return value. Oracle Database interprets the empty string as null, and if this function has a null argument, then it returns null. To remove all characters in from_string
, concatenate another character to the beginning of from_string
and specify this character as the to_string
. For example, TRANSLATE
(expr
, 'x0123456789
', 'x
') removes all digits from expr
.
TRANSLATE
provides functionality related to that provided by the REPLACE
function. REPLACE
lets you substitute a single string for another single string, as well as remove character strings. TRANSLATE
lets you make several single-character, one-to-one substitutions in one operation.
This function does not support CLOB
data directly. However, CLOB
s can be passed in as arguments through implicit data conversion.
The following statement translates a book title into a string that could be used (for example) as a filename. The from_string
contains four characters: a space, asterisk, slash, and apostrophe (with an extra apostrophe as the escape character). The to_string
contains only three underscores. This leaves the fourth character in the from_string
without a corresponding replacement, so apostrophes are dropped from the returned value.
SELECT TRANSLATE('SQL*Plus User''s Guide', ' */''', '___') FROM DUAL; TRANSLATE('SQL*PLUSU -------------------- SQL_Plus_Users_Guide