Oracle® Database SQL Language Reference 11g Release 2 (11.2) Part Number E17118-04 |
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TRIM
enables you to trim leading or trailing characters (or both) from a character string. If trim_character
or trim_source
is a character literal, then you must enclose it in single quotation marks.
If you specify LEADING
, then Oracle Database removes any leading characters equal to trim_character
.
If you specify TRAILING
, then Oracle removes any trailing characters equal to trim_character
.
If you specify BOTH
or none of the three, then Oracle removes leading and trailing characters equal to trim_character
.
If you do not specify trim_character
, then the default value is a blank space.
If you specify only trim_source
, then Oracle removes leading and trailing blank spaces.
The function returns a value with data type VARCHAR2
. The maximum length of the value is the length of trim_source
.
If either trim_source
or trim_character
is null, then the TRIM
function returns null.
Both trim_character
and trim_source
can be VARCHAR2
or any data type that can be implicitly converted to VARCHAR2
. The string returned is a VARCHAR2
(NVARCHAR2
) data type if trim_source
is a CHAR
or VARCHAR2
(NCHAR
or NVARCHAR2
) data type, and a CLOB
if trim_source
is a CLOB
data type. The return string is in the same character set as trim_source
.
This example trims leading zeros from the hire date of the employees in the hr
schema:
SELECT employee_id, TO_CHAR(TRIM(LEADING 0 FROM hire_date)) FROM employees WHERE department_id = 60 ORDER BY employee_id; EMPLOYEE_ID TO_CHAR(T ----------- --------- 103 20-MAY-08 104 21-MAY-07 105 25-JUN-05 106 5-FEB-06 107 7-FEB-07