MySQL 从字符串中删除不需要的字符

备注:测试数据库版本为MySQL 8.0

如需要scott用户下建表及录入数据语句，可参考:
scott建表及录入数据sql脚本

一.需求

将emp表中的元音字母 AEIOU都去除掉

二.解决方案

通过MySQL的replace函数进行多次替换可以解决这个问题
也可以通过MySQL的正则表达式来处理

代码:

select ename,replace(replace(replace(replace(replace(ename,'A',''),'E',''),'I',''),'O',''),'U','') as new_name from emp;

select ename,regexp_replace(ename,'[AEIOU]','') as new_name from emp;

测试记录:

mysql> select ename,replace(replace(replace(replace(replace(ename,'A',''),'E',''),'I',''),'O',''),'U','') as new_name from emp;
+--------+----------+
| ename  | new_name |
+--------+----------+
| SMITH  | SMTH     |
| ALLEN  | LLN      |
| WARD   | WRD      |
| JONES  | JNS      |
| MARTIN | MRTN     |
| BLAKE  | BLK      |
| CLARK  | CLRK     |
| SCOTT  | SCTT     |
| KING   | KNG      |
| TURNER | TRNR     |
| ADAMS  | DMS      |
| JAMES  | JMS      |
| FORD   | FRD      |
| MILLER | MLLR     |
+--------+----------+
14 rows in set (0.00 sec)

mysql> select ename,regexp_replace(ename,'[AEIOU]') as new_name from emp;
ERROR 1582 (42000): Incorrect parameter count in the call to native function 'regexp_replace'
mysql>
mysql>
mysql>
mysql> select ename,regexp_replace(ename,'[AEIOU]','') as new_name from emp;
+--------+----------+
| ename  | new_name |
+--------+----------+
| SMITH  | SMTH     |
| ALLEN  | LLN      |
| WARD   | WRD      |
| JONES  | JNS      |
| MARTIN | MRTN     |
| BLAKE  | BLK      |
| CLARK  | CLRK     |
| SCOTT  | SCTT     |
| KING   | KNG      |
| TURNER | TRNR     |
| ADAMS  | DMS      |
| JAMES  | JMS      |
| FORD   | FRD      |
| MILLER | MLLR     |
+--------+----------+
14 rows in set (0.00 sec)

mysql>