Thanks to @enihsyou

实验三.md

@@ -167,6 +167,12 @@ ALTER TABLE employee ADD CONSTRAINT Check_Sex CHECK (emp_sex IN ("男", "女", "
 ALTER TABLE employee ADD CHECK(emp_no RLIKE "[0-9][0-9][0-9][0-9][0-9]");
 ```
 
+如果用 REGEX 的话就是
+
+```mysql
+ALTER TABLE employee ADD CONSTRAINT CHECK (emp_no REGEXP '\\d{5}');
+```
+
 或者，输入的编号必须以 E 开头的 5 位数编号
 
 ```mysql