如何避免数据库中的重复？-Howtoavoidduplicatesinadatabase?

I'm using a relational database which contains two tables:

我正在使用包含两个表的关系数据库：

PASSWORD:
  id (primary key)
  idEquipment (Foreign key)
  password (varchar)

EQUIPMENT :
  id (primary key and REFERENCES)
  type (varchar)
  model (varchar)

The question is how to avoid duplicates password in the table PASSWORD because many equipments have the same value of password ?

问题是如何避免表PASSWORD中的重复密码，因为许多设备具有相同的密码值？

Thanks for your answers.

谢谢你的回答。

1 个解决方案

PASSWORD:
  id (primary key)
  idEquipment (Foreign key)
  password (varchar) UNIQUE

EQUIPMENT :
  id (primary key and REFERENCES)
  type (varchar)
  model (varchar)