Match any sequence of one or more a characters: a+ : One or More « Regular Expressions « MySQL Tutorial

1. MySQL Tutorial
2. Regular Expressions
3. One or More

mysql>
mysql> SELECT 'ABC' REGEXP '^Aa+';
+---------------------+
| 'ABC' REGEXP '^Aa+' |
+---------------------+
|                   0 |
+---------------------+
1 row in set (0.00 sec)

mysql>
mysql> SELECT 'ABC' REGEXP '^ABa+';
+----------------------+
| 'ABC' REGEXP '^ABa+' |
+----------------------+
|                    0 |
+----------------------+
1 row in set (0.00 sec)

mysql>