没有性能影响.优化器将 IN 转换为一系列 OR 运算的 = 操作.

There is no performance hit. The optimizer converts the IN to a series of = operations ORed together.

顺便说一句，我希望您在实际查询中并没有真正使用 SELECT *.

As a side note, I hope you're not really using SELECT * in your actual queries.