MySQL Tutorial/Subquery/ALL

Greater than ALL

If table t2 is empty, the result is TRUE.

So, the following statement is TRUE when table t2 is empty:

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SELECT * FROM t1 WHERE 1 > ALL (SELECT s1 FROM t2);</source>

NULL subquery with "> ALL"

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SELECT * FROM t1 WHERE 1 > ALL (SELECT MAX(s1) FROM t2) is NULL when table t2 is empty: SELECT * FROM t1 WHERE 1 > ALL (SELECT MAX(s1) FROM t2);</source>

Subqueries with ALL

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Syntax:

  operand comparison_operator ALL (subquery)</source>