TRIM_IN

Description

The TRIM_IN function is used to remove leading and trailing specified characters from a string. If no character set is specified, it removes leading and trailing spaces by default. When a character set is specified, it removes all specified characters from both ends (regardless of their order in the set).

The key feature of TRIM_IN is that it removes any combination of characters from the specified set, while the TRIM function removes characters based on exact string matching.

Syntax

TRIM_IN(<str>[, <rhs>])

Parameters

Parameter	Description
<str>	The string to be processed. Type: VARCHAR
<rhs>	Optional parameter, the set of characters to be removed. Type: VARCHAR

Return Value

Returns VARCHAR type, representing the processed string.

Special cases:

• If str is NULL, returns NULL
• If rhs is not specified, removes all leading and trailing spaces
• If rhs is specified, removes all characters from both ends that appear in rhs until encountering characters not in rhs

Examples

1. Remove leading and trailing spaces

SELECT trim_in('   ab d   ') str;

+------+
| str  |
+------+
| ab d |
+------+

2. Remove specified character set

SELECT trim_in('ababccaab', 'ab') str;

+------+
| str  |
+------+
| cc   |
+------+

3. Comparison with TRIM function

SELECT trim_in('ababccaab', 'ab'), trim('ababccaab', 'ab');

+-----------------------------+--------------------------+
| trim_in('ababccaab', 'ab')  | trim('ababccaab', 'ab')  |
+-----------------------------+--------------------------+
| cc                          | ababccaab                |
+-----------------------------+--------------------------+

4. Character set order does not matter

SELECT trim_in('abcHelloabc', 'cba');

+--------------------------------+
| trim_in('abcHelloabc', 'cba')  |
+--------------------------------+
| Hello                          |
+--------------------------------+

5. UTF-8 character support

SELECT trim_in('+++ṭṛì ḍḍumai+++', '+');

+--------------------------------------+
| trim_in('+++ṭṛì ḍḍumai+++', '+')    |
+--------------------------------------+
| ṭṛì ḍḍumai                           |
+--------------------------------------+

6. NULL value handling

SELECT trim_in(NULL, 'abc');

+-----------------------+
| trim_in(NULL, 'abc')  |
+-----------------------+
| NULL                  |
+-----------------------+

7. Empty character handling

SELECT trim_in('', 'abc'), trim_in('abc', '');

+--------------------+--------------------+
| trim_in('', 'abc') | trim_in('abc', '') |
+--------------------+--------------------+
|                    | abc                |
+--------------------+--------------------+

Keywords

TRIM_IN, TRIM