An EXISTS predicate tests for the existence of a row satisfying the
search condition of a subquery.
The predicate evaluates to TRUE if at least one row satisfies the
search condition of the subquery.
Scope |
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SQL Data Manipulation Statements
SQL Syntax |
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Parameters |
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- SubQuery
A subquery is a nested query.
The syntax of subqueries is presented in the description of the SELECT
statement in the "SQL Statements" chapter.
Description |
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Unlike other places in which subqueries occur, the EXISTS predicate
allows the subquery to specify more than one column in its select list.
Example |
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Get supplier names for suppliers who provide at least one part.
SELECT S.SNAME
FROM S
WHERE EXISTS ( SELECT * FROM SP
WHERE SP.SNO = S.SNO );
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