Database keys

Database keys are essential for organizing and managing data effectively. In this post, we'll explore ten key concepts that every IT professional should know.

1. 🗝 𝗣𝗿𝗶𝗺𝗮𝗿𝘆 𝗞𝗲𝘆
- A unique identifier for each record in a table.
- Cannot be null.
- Ensures that each row is unique.

2. 🌉 𝗙𝗼𝗿𝗲𝗶𝗴𝗻 𝗞𝗲𝘆
- A field in one table that refers to the Primary Key of another table.
- Establishes relationships between tables.

3. 🧩 𝗖𝗼𝗺𝗽𝗼𝘀𝗶𝘁𝗲 𝗞𝗲𝘆
- A combination of two or more columns that uniquely identifies each record.
- Useful when a single column can't uniquely identify a record.

4. 💪 𝗦𝘂𝗽𝗲𝗿 𝗞𝗲𝘆
- One or more columns that can uniquely identify a record.
- A Primary Key is a type of Super Key.

5. 🏅 𝗖𝗮𝗻𝗱𝗶𝗱𝗮𝘁𝗲 𝗞𝗲𝘆
- A column or set of columns that could be the Primary Key.
- Must be unique.

6. 🔍 𝗨𝗻𝗶𝗾𝘂𝗲 𝗞𝗲𝘆
- Ensures uniqueness for a column or column combination.
- Similar to Primary Key but allows one null value.

7. 🛤 𝗔𝗹𝘁𝗲𝗿𝗻𝗮𝘁𝗲 𝗞𝗲𝘆
- A Candidate Key that isn't the Primary Key.
- Another option for a unique identifier.

8. 🍃 𝗡𝗮𝘁𝘂𝗿𝗮𝗹 𝗞𝗲𝘆
- A key that's a natural part of the data, like an email address.

9. 🎭 𝗦𝘂𝗿𝗿𝗼𝗴𝗮𝘁𝗲 𝗞𝗲𝘆
- An artificial key created when no natural unique identifier exists.

10. 🔑 𝗦𝗲𝗰𝗼𝗻𝗱𝗮𝗿𝘆 𝗞𝗲𝘆
- Used for data retrieval, not identification.
- Helps create non-clustered indexes.