Available in versions: Dev (3.18) | Latest (3.17) | 3.16 | 3.15

QUALIFY to derived table

Applies to ❌ Open Source Edition   ✅ Express Edition   ✅ Professional Edition   ✅ Enterprise Edition

Teradata introduced the useful QUALIFY clause, which has since been reproduced by a number of implementations. jOOQ can transform a query containing the QUALIFY clause to an equivalent query filtering on a derived table

This transformation allows for transforming some of these syntaxes to equivalent, standard syntax using window functions and derived tables:

-- Input
SELECT * 
FROM
  t 
QUALIFY 
  row_number () OVER (ORDER BY id) <= 5
-- Output
SELECT * 
FROM (
  SELECT *, row_number () OVER (ORDER BY id) AS rn FROM t
) AS t
WHERE t.rn <= 5

Example configuration

Settings settings = new Settings()
    .withTransformQualify(Transformation.WHEN_NEEDED);

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