Available in versions: Dev (3.20)

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MAX_BY

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

The MAX_BY() aggregate function calculates a value at the row containing the maximum value of all by values. This works the same way as the Oracle specific KEEP clause.

SELECT max_by(AUTHOR_ID, ID)
FROM BOOK
create.select(maxBy(BOOK.AUTHOR_ID, BOOK.ID))
      .from(BOOK)

Producing:

+--------+
| max_by |
+--------+
|      2 |
+--------+

Dialect support

This example using jOOQ:

maxBy(BOOK.AUTHOR_ID, BOOK.ID)

Translates to the following dialect specific expressions:

Aurora Postgres, CockroachDB, H2, Postgres, YugabyteDB

(array_agg(BOOK.AUTHOR_ID ORDER BY BOOK.ID DESC))[1]

BigQuery, DuckDB, Snowflake, Trino

max_by(BOOK.AUTHOR_ID, BOOK.ID)

ClickHouse

argMax(BOOK.AUTHOR_ID, BOOK.ID)

Hana

last_value(BOOK.AUTHOR_ID ORDER BY BOOK.ID)

HSQLDB

CASE
  WHEN cardinality(array_agg(BOOK.AUTHOR_ID ORDER BY BOOK.ID DESC)) >= 1 THEN (array_agg(BOOK.AUTHOR_ID ORDER BY BOOK.ID DESC))[1]
END

Oracle

max(BOOK.AUTHOR_ID) KEEP (DENSE_RANK LAST ORDER BY BOOK.ID)

ASE, Access, Aurora MySQL, DB2, Derby, Exasol, Firebird, Informix, MariaDB, MemSQL, MySQL, Redshift, SQLDataWarehouse, SQLServer, SQLite, Sybase, Teradata, Vertica

/* UNSUPPORTED */
Generated with jOOQ 3.20. Translate your own SQL on our website

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