Why Does SQL Server Avoid Natural Joins, and How Can I Achieve the Same Result?

Natural Joins in SQL Server: Unsupported But Unnecessary

While natural joins are not explicitly supported in Microsoft SQL Server, it raises the question of whether there are alternative methods to achieve similar functionality.

Natural Joins vs. Explicit Joins

Natural joins automatically match columns between tables that share the same name. However, explicit joins, using ON clauses, provide greater control and clarity. The explicit JOIN syntax is straightforward and eliminates any potential ambiguity or unexpected join conditions based on column names alone.

Why Microsoft SQL Server Embraces Explicit Joins

Experts strongly advocate for explicit joins in SQL Server due to several reasons:

• Clarity: Explicit joins clearly define the join conditions, leaving no room for interpretation.
• Column Naming Precision: Using explicit joins allows you to name columns appropriately without worrying about naming conflicts or side effects in other tables.
• Control: Explicit joins empower developers to specify the exact join conditions they intend, avoiding unexpected surprises.

Additional Resources

• [SQL Server - lack of NATURAL JOIN / x JOIN y USING(field)](https://stackoverflow.com/questions/1347069/sql-server-lack-of-natural-join-x-join-y-usingfield)
• [is NATURAL JOIN any better than SELECT FROM WHERE in terms of performance ?](https://stackoverflow.com/questions/136025/is-natural-join-any-better-than-select-from-where-in-terms-of-performance)

Therefore, while natural joins may offer apparent convenience, the clarity, control, and reliability provided by explicit joins make them the preferred choice in SQL Server development.

The above is the detailed content of Why Does SQL Server Avoid Natural Joins, and How Can I Achieve the Same Result?. For more information, please follow other related articles on the PHP Chinese website!