What is the difference between a primary key and a unique key?

What is the difference between a primary key and a unique key?

题目类型: 技术面试题

这是一道技术面试题，常见于澳洲IT公司面试中。

难度: medium

标签: intellipaat, sql, topic-specific, sql, database

参考答案摘要

A Primary Key uniquely identifies each record in a table and cannot be NULL, whereas a Unique Key ensures uniqueness but allows one NULL value. | Feature | Primary Key | Unique Key | | --- | --- | ---...

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