Not exists vs not in oracle IN (vs) EXISTS and NOT IN (vs) NOT EXISTS Hi Tom, Can you pls explain the diff between IN and EXISTS and NOT IN and NOT EXISTS. Specifically, when NULLs are involved they will return different results. Products p WHERE NOT EXISTS ( SELECT 1 FROM Northwind. See Joe Celko's 'SQL for smarties' for a better explanation of when to use each. See full list on oracletutorial. com Oct 15, 2024 · This post compares SQL’s NOT IN and NOT EXISTS, focusing on NULL handling, performance differences, and debunking common myths about their usage and interchangeability. Aug 23, 2010 · In Oracle SQL queries, IN and EXISTS are interchangeable. Nov 9, 2009 · The most important difference is the handling of nulls. You might find that the existence of nulls causes exists to fail. Jan 4, 2024 · IN (vs) EXISTS and NOT IN (vs) NOT EXISTS Hi Tom, Can you pls explain the diff between IN and EXISTS and NOT IN and NOT EXISTS. Nov 14, 2002 · Hi everybody, Does anyone know if rewriting a query to use the MINUS operator instead of using NOT EXISTS in the query is faster, giving all else is the same? Thanks very much! Bill Loggins 801-97 IN (vs) EXISTS and NOT IN (vs) NOT EXISTS Hi Tom, Can you pls explain the diff between IN and EXISTS and NOT IN and NOT EXISTS. ID); And this result returns 85k records VS 0 from the example above. If there are not any courses that means our subquery will return 0. It allows developers to create robust, modular, and reusable code for implementing data manipulation, and transaction control in databases. This article compares efficiency of these methods in Oracle. To be totally From Table Where table. Jul 23, 2025 · Output: geeksforgeeks - NOT EXISTS Explanation: In the above query, we have specified in a subquery that there should not be any course named 'DSA' in our courses table. I've never seen this behavior before, does anyone know what might be going on and why the NOT IN isn't returning the same results as NOT EXISTS?. Many of us assume therefore, that NOT IN and NOT EXISTS are also interchangeable. Two crucial operators in PL/SQL are NOT IN and NOT EXISTS, which are often used to filter data based on specific conditions in subqueries. Regards,Madhusudhana Rao. Dec 17, 2023 · NOT IN is different then NOT exists but NOT EXISTS and NOT IN are the same when the subquery you use in the NOT IN does not contain NULLS. Nov 5, 2024 · PL/SQL is a Procedural Language/Structured Query Language. Therefore, NOT EXISTS, being a negation operator will display all the rows from geeksforgeeks table. Jul 22, 2025 · Explore the nuances between SQL's NOT EXISTS and NOT IN, focusing on performance impacts, null value behavior, and optimal usage scenarios with code examples. Your query might seem to work the same with both in and exists, but when your sub-query returns null you might get a shock. ID = A. That's not the case though. . Mar 16, 2025 · Struggling with tricky SQL queries? Learn why NOT EXISTS is often faster and more reliable than NOT IN, especially when dealing with NULL values. Understanding the differences between these two operators Sep 17, 2009 · A comparison of three methods to fetch rows present in one table but absent in another one, namely NOT IN, NOT EXISTS and LEFT JOIN / IS NULL. Oct 21, 2012 · Use NOT EXISTS. Because I have read that EXISTS will work better thanIN and NOT EXISTS will work better than NOT IN (read this is Oracle server tunning). column = the table identifier with the name of the column. Both of not in and not exists can be very efficient when there are no nulls (and not in WITH THE CBO is pretty good -- using an "anti join" -- see the design/tuning for performance guide for details on that). This detailed SQL tutorial breaks down the key differences, performance insights, and best practices — helping you avoid common pitfalls and ace your next SQL interview question! This snippet includes the focus keywords "NOT EXISTS vs NOT IN," "SQL May 13, 2020 · Alternatively, I tried using NOT EXISTS: select ID from TableA A where NOT EXISTS (select ID from tableB B where B. P IN (vs) EXISTS and NOT IN (vs) NOT EXISTS Hi Tom, Can you pls explain the diff between IN and EXISTS and NOT IN and NOT EXISTS. [Order Details] od WHERE p. Which of these queries is the faster? NOT EXISTS: SELECT ProductID, ProductName FROM Northwind. column is not null AND table. value from tmpIDtable) table. column NOT Exists (Select column. The most important thing to note about NOT EXISTS and NOT IN is that, unlike EXISTS and IN, they are not equivalent in all cases. The execution plans may be the same at the moment but if either column is altered in the future to allow NULLs the NOT IN version will need to do more work. iirfskwl txzdn rtu smmtxgl jjixjw nvxuy ftnkyt ygdvzfwd bozttg ver gowxtmr bjowgqh ydeb blxdg risbfw