SQL ENUM data type is evil ^83%

SQL ENUM Data Type is Evil

As a developer, I've seen it time and time again: the temptation to use the SQL ENUM data type. It seems like an easy solution to restrict a field to a specific set of values, but trust me, it's a path you'll regret taking.

The Allure of ENUM

The ENUM data type is designed to store a limited number of predefined values in a single column. It's often used for fields like:

• Color (red, green, blue)
• Day of the week (Monday, Tuesday, Wednesday)
• Country code (USA, Canada, Mexico)

On the surface, ENUM seems harmless and even useful. But beneath this façade lies a world of problems waiting to happen.

The Problems with ENUM

Using ENUM data type can lead to several issues:

• Inflexibility: Once you create an ENUM column, it's difficult to modify or extend its values without modifying the underlying database schema.
• Data redundancy: If you store an enum value as a string in another table, you'll end up duplicating the list of possible values.
• Query complexity: When working with ENUM data, queries can become cumbersome and harder to maintain.

The Dark Side of ENUM

ENUM is often used to simplify database design, but it can lead to:

• Rigidity: ENUM constraints make it challenging to store new or unexpected values that don't fit the predefined list.
• Data inconsistencies: When using ENUM, data can become inconsistent across different rows or tables if not properly managed.

The Alternatives

So, what's a better approach? Consider these alternatives:

• Strings: Store possible values as strings and use indexing or other optimization techniques to improve query performance.
• Separate tables: Use separate tables for each set of predefined values, making it easier to manage and extend the data.

Conclusion

In conclusion, SQL ENUM data type is a relic of the past. Its limitations and inflexibility can lead to maintenance headaches and inconsistencies in your database. As developers, we should strive for more flexible and maintainable solutions that prioritize adaptability over convenience.

When working with predefined sets of values, remember: ENUM may seem like an easy solution, but it's often a path to trouble. Choose the right tool for the job, and avoid the evil of ENUM data type in your database design.