any sample?

快速插入数据的时候唯一验证不工作

This helper validates that the attribute's value is unique right before the object gets saved. It does not create a uniqueness constraint in the database, so it may happen that two different database connections create two records with the same value for a column that you intend to be unique. To avoid that, you must create a unique index on that column in your database.

https://guides.rubyonrails.org/active_record_validations.html#uniqueness

加个数据库唯一索引？

db unique index.

数据库加索引，重复插入会报 500 error，对吗？如果是这样太不友好了叭，我害得写异常处理……

报不报错都应该在数据库加约束啊

500 比清除重复数据好处理，比如 rescue 之后返给前端个提示“xxx 被占用”