A table is in 2NF when it is in 1NF and it includes no partial dependencies. However, a table in 2NF may still have transitive dependencies, i.e., dependencies based on attributes that are not part of the primary key.
A table is in 2nd Normal Form (2NF) when it meets the following criteria:
- It is in 1st Normal Form (1NF)
- All non-primary key columns are fully dependent on the primary key. In other words, non-primary key columns cannot be functionally dependent on only a subset of the primary key.
A table in 2NF is considered to be free of partial dependencies.