First normal form

Learn first normal form (1NF).

1NF

1NF requires each cell to hold a single value. Comma-separated lists are forbidden.

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1NF wants single values.

1NF requires atomic values. A single cell cannot hold a list or set.

For example, instead of storing "555-1, 555-2" in a phones column, you create a customer_phones table with one row per phone.

Bring an orders table to 1NF: each product on its own row.

Show example solution

CREATE TABLE order_items (
  order_id INT,
  product VARCHAR(50),
  qty INT
)

1NF value

1NF: each cell holds an ____ value

Show answer

1NF: each cell holds an atomic value