Should I Store Lists in a Single Database Column, or is a Separate Table Always Better?

How to Store a List in a Database Column: Why Traditional Methods Are Still the Best

Although it's possible to store a list in a database column through serialization or XML/CSV, seasoned SQL developers strongly advise against these approaches. Relational databases are designed for one-value-per-column storage. Storing a list in a single column violates first normal form, undermining database normalization.

First normal form ensures data integrity by eliminating logical inconsistencies and potential corruption. It requires:

1. Rows are distinct and can be identified by a primary key.
2. Data ordering is defined by the data itself, not row order.
3. Each row/column intersection contains only one value.

By storing a list in a column, you're breaking the third rule. While it may seem efficient in the case of your function table, it can lead to trouble down the road. You'll encounter scenarios where your nonstandard approach becomes inappropriate, hampering your ability to write efficient queries.

Instead of storing lists in columns, create another table to hold the list elements and link them to the main table. This approach is more straightforward, ensures data integrity, and allows LINQ to SQL to automatically provide the object-oriented interface to your list.

In short, while unconventional methods may be tempting, adhering to established database design principles will ultimately save you time, improve data reliability, and allow for seamless integration with ORMs like LINQ to SQL.

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