Where Archives - Database Tips

SQL: from [Not] In to [Not] Exists in 3 steps

For many people, using noncorrelated subqueries (using In/Not In) seems to be more natural than using Exists/Not Exists and correlated[…]

Duplicate data can be generated in the database due to design error, software bugs or misuse by end users. Depending[…]

Non-correlated subqueries (where the inner query does not have any column from the outer query tables) are usually implemented using[…]

The Where clause is one of the mostly commonly used clauses in the SQL language. On the other hand, the[…]