Explicit vs Implicit SQL Server Joins

SQL Joins

A join is a mechanism that combines rows from two or more tables based on a related column between them. The purpose of using joins is to retrieve data from multiple tables in a single result set. The common columns used for joining tables are usually primary and foreign keys....

Implicit Join

Also known as traditional or comma-separated joins, implicit joins specify the join condition using the WHERE clause. Tables are listed in the FROM clause, separated by commas, and the join condition is specified in the WHERE clause using equality operators. Implicit joins are considered outdated and less readable compared to explicit joins....

Explicit Join

Explicit joins use the JOIN keyword to specify the join condition directly in the ON clause. This approach provides better readability and clarity, as the relationship between tables is explicitly stated in the query. Types of explicit joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN....

Explicit vs Implicit SQL Server Joins

Aspect Explicit Joins Implicit Joins Syntax Uses the JOIN keyword with ON clause. Lists tables in the FROM clause, join condition in the WHERE clause. Readability Generally more readable and explicit. May be less readable, especially in complex queries. Clarity Clearly separates join conditions from other filtering criteria. Mixes join conditions with other filtering criteria. Maintenance Easier to maintain and debug. May be harder to maintain, especially in complex queries. Types of Joins Supports different types of joins: INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL JOIN, etc. Supports basic join functionality without explicit indication of join type. Best Practice Recommended practice for modern SQL development. Considered outdated, but still valid SQL syntax....

Conclusion

Explicit Joins...