能否举个例子呢？
我目前简单复现没有成功：

select * from cashout;
+------+--------+--------+
| a | amount | bet_id |
+------+--------+--------+
| 1 | 1 | 1 |
| 2 | 2 | 2 |
+------+--------+--------+
mysql> select * from bet;
+------+----------+--------+
| b | order_id | bet_id |
+------+----------+--------+
| 11 | 11 | 11 |
| 13 | 13 | 2 |

case1: 结果正确
select sum(amount) from cashout where bet_id in(select bet_id from bet where order_id in (13));
+-------------+
| sum(amount) |
+-------------+
| 2 |
+-------------+
case 2: 结果正确
select sum(amount) from cashout where bet_id in(select bet_id from bet where order_id in (11));
+-------------+
| sum(amount) |
+-------------+
| NULL |
+-------------+
1 row in set (0.00 sec)
case 3: 结果正确
select sum(amount) from cashout where bet_id in(select bet_id from bet where order_id in (15));
+-------------+
| sum(amount) |
+-------------+
| NULL |
+-------------+
1 row in set (0.01 sec)

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bet实际上没有bet_id这个字段，这个语句cetus应该报语法错误。但是没有报而是把这个条件忽略了

from cetus.

直连cetus和直连MySQL的结果一致。

from cetus.

这个应该是MySQL本身的问题

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