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

需要判断字符串中是否只包含数字和字符，如果包含其他的，不显示数据

二.解决方案

这类需求，只能考虑使用正则表达式来解决

代码

create view v as
select ename as data
 from emp
where deptno = 10
union all
select concat(ename,',$',cast(sal as char(4) ),'.00') as data
from emp
where deptno = 20
union all
select concat(ename,',$',cast(deptno as char(4))) as data
from emp
where deptno = 30;


select data
from V
where data regexp '[^0-9a-zA-Z]' = 0;

测试记录:

mysql> drop view v ;
Query OK, 0 rows affected (0.01 sec)

mysql> create view v as
    -> select ename as data
    ->  from emp
    -> where deptno = 10
    -> union all
    -> select concat(ename,',$',cast(sal as char(4) ),'.00') as data
    -> from emp
    -> where deptno = 20
    -> union all
    -> select concat(ename,',$',cast(deptno as char(4))) as data
    -> from emp
    -> where deptno = 30
    -> ;
Query OK, 0 rows affected (0.01 sec)

mysql> select * from v;
+----------------+
| data           |
+----------------+
| CLARK          |
| KING           |
| MILLER         |
| SMITH,$800..00 |
| JONES,$2975.00 |
| SCOTT,$3000.00 |
| ADAMS,$1100.00 |
| FORD,$3000.00  |
| ALLEN,$30      |
| WARD,$30       |
| MARTIN,$30     |
| BLAKE,$30      |
| TURNER,$30     |
| JAMES,$30      |
+----------------+
14 rows in set, 7 warnings (0.01 sec)

mysql>
mysql> select data
    -> from V
    -> where data regexp '[^0-9a-zA-Z]' = 0;
+--------+
| data   |
+--------+
| CLARK  |
| KING   |
| MILLER |
+--------+
3 rows in set, 7 warnings (0.00 sec)