Not In And Not Exists

Not In And Not Exists. NOT IN vs NOT EXISTS in PostgreSQL WHERE NOT EXISTS (SELECT 1 FROM employees m where m.manager_id=e.employee_id); Output: query output My preference for this pattern is definitely NOT EXISTS: SELECT CustomerID FROM Sales.Customer AS c WHERE NOT EXISTS ( SELECT 1 FROM Sales.SalesOrderHeaderEnlarged WHERE CustomerID = c.CustomerID );

Even if only a single value in the given data is NULL, the whole result will be empty where 3 not in (1, null) is UNKNOWN as it is not known whether 3 is in null or not

In, Exists, Not in & Not Exists 4.1/5 (9) Notesassumptions Your Rating PDF Data Management

where 3 not in (1, null) is UNKNOWN as it is not known whether 3 is in null or not Explanation: As we can see from the above image, we didn't need to specially handle NULL values in the case of NOT EXISTS statement My preference for this pattern is definitely NOT EXISTS: SELECT CustomerID FROM Sales.Customer AS c WHERE NOT EXISTS ( SELECT 1 FROM Sales.SalesOrderHeaderEnlarged WHERE CustomerID = c.CustomerID );

Oracle中的not in 和not exists_oracle not in 索引CSDN博客. The main disadvantage of NOT IN is that it does not support NULL value For this, we can use NOT EXISTS, which negates the logic of the EXISTS operator

SQL中的in与not in、exists与not exists的区别以及性能分析_not exists和not inCSDN博客. WHERE NOT EXISTS (SELECT 1 FROM employees m where m.manager_id=e.employee_id); Output: query output It's typically more efficient than NOT IN , particularly when handling NULL values