TRANSLATE
Description of the illustration translate.gif
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. If expr is a character string, then you must enclose it in single quotation marks. 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 char, then they are removed from the return value.
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.
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, CLOBs 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
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SQL_Plus_Users_Guide