没有人知道?
SELECT * FROM student
和SELECT student_id FROM absence
都是可以正常执行的。
就是 SELECT * FROM student WHERE student_id IN (SELECT student_id FROM absence) 不可以,一用,就说有语法错误。
student table:
mysql> SELECT * FROM student;
+-----------+-----+------------+
| name | sex | student_id |
+-----------+-----+------------+
| Megan | F | 1 |
| Joseph | M | 2 |
| Kyle | M | 3 |
| Katie | F | 4 |
| Abby | F | 5 |
| Nathan | M | 6 |
| Liesl | F | 7 |
| Ian | M | 8 |
| Colin | M | 9 |
.....