数据库设计三范式
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manxingxing commented
1NF
A relation is in first normal form if and only if the domain of each attribute contains only atomic (indivisible) values, and the value of each attribute contains only a single value from that domain
2NF
a relation is in 2NF if every non-prime attribute of the relation is dependent on the whole of every candidate key
3NF
A database relation (e.g. a database table) is said to meet third normal form standards if all the attributes (e.g. database columns) are functionally dependent on solely the primary key