Returns whether or not any rows exist in a given subquery.

Syntax

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EXISTS(<QueryExpression>)

<QueryExpression> = SELECT statement

Returns

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BOOLEAN

Usage

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The EXISTS function returns the TRUE if a given sub-query returns any rows, or FALSE if the sub-query does not return any rows. EXISTS is useful in situations where you simply want to know if any rows are present for a given set of conditions, which would be expressed via the WHERE clause of the sub-query.

Examples

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SELECT *
FROM Customers
WHERE EXISTS(SELECT * FROM Orders
             WHERE Orders.CustomerNo=Customers.CustomerNo)

SQL 2003 Standard Deviations

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This function deviates from the SQL 2003 standard in the following ways: