How do SQL EXISTS statements work? - Stack Overflow
Nov 18, 2013 · In order to filter the student records that have a 10 grade in Math, we can use the EXISTS SQL operator, like this: SELECT id, first_name, last_name FROM student WHERE …
Difference between EXISTS and IN in SQL? - Stack Overflow
Aug 24, 2008 · Edit: The reason I'm asking is that in many cases you can rewrite an SQL based on IN to use an EXISTS instead, and vice versa, and for some database engines, the query …
SQL: How to properly check if a record exists - Stack Overflow
Nov 23, 2010 · You can use: SELECT COUNT(1) FROM MyTable WHERE ... or. WHERE [NOT] EXISTS ( SELECT 1 FROM MyTable WHERE ... ) This will be more efficient than SELECT * …
SQL Server: IF EXISTS ; ELSE - Stack Overflow
I know its been a while since the original post but I like using CTE's and this worked for me: WITH cte_table_a AS ( SELECT [id] [id] , MAX([value]) [value] FROM table_a GROUP BY [id] ) …
sql - NOT IN vs NOT EXISTS - Stack Overflow
May 18, 2007 · The database engine does not have to run the subquery entirely. If a single record is matched, the EXISTS operator returns true, and the associated other query row is selected. …
sql - EXISTS vs JOIN and use of EXISTS clause - Stack Overflow
Jan 7, 2020 · Please note that EXISTS with an outer reference is a join, not just a clause. It is a semi-join (and NOT EXISTS is an anti-semi-join). Also, you can use EXISTS to join tables, …
SQL Queries using EXISTS and OR operator - Stack Overflow
Dec 20, 2012 · If you wanted to use EXISTS, you can of course turn this around, but the query may not be able to use indexes (you can remove the DISTICT for this query): SELECT * …
How to use SQL Select statement with IF EXISTS sub query?
You can use EXISTS to check if a column value exists in a different table. SELECT TABLE1.id, EXISTS (SELECT 1 FROM TABLE2 WHERE TABLE2.id = TABLE1.id) AS columnName …
How do I use T-SQL's Exists keyword? - Stack Overflow
Jul 27, 2011 · The result set can be returned with a query that uses an EXISTS predicate. (Note that the title of the OP question did ask about how to use the EXISTS keyword.) Here is …
How can I use AND condition in IF EXISTS in SQL?
Jul 1, 2013 · Also, you should include TABLE_SCHEMA in your INFORMATION_SCHEMA.COLUMNS query, otherwise you will get wrong result if the same …