TRIM()

TRIM([[BOTH | LEADING | TRAILING] [remstr] FROM] str)

Devuelve la cadena str eliminando todos los prefijos y/o sufijos remstr. Si no se incluye ninguno de los especificadores BOTH, LEADING o TRAILING, se asume BOTH. Si no se especifica la cadena remstr, se eliminan los espacios:

mysql> SELECT TRIM('  bar   ');
+------------------------------------+
| TRIM(LEADING 'x' FROM 'xxxbarxxx') |
+------------------------------------+
| barxxx                             |
+------------------------------------+
1 row in set (0.00 sec)

mysql> SELECT TRIM(BOTH 'x' FROM 'xxxbarxxx');
+---------------------------------+
| TRIM(BOTH 'x' FROM 'xxxbarxxx') |
+---------------------------------+
| bar                             |
+---------------------------------+
1 row in set (0.00 sec)

mysql> SELECT TRIM(TRAILING 'xyz' FROM 'barxxyz');
+-------------------------------------+
| TRIM(TRAILING 'xyz' FROM 'barxxyz') |
+-------------------------------------+
| barx                                |
+-------------------------------------+
1 row in set (0.00 sec)

Esta función es segura "multi-byte".