This documentation is for the unreleased development version of jOOQ. Click on the above version links to get this documentation for a supported version of jOOQ.
ARRAY_MAP
Applies to ✅ Open Source Edition ✅ Express Edition ✅ Professional Edition ✅ Enterprise Edition
The ARRAY_MAP function allows for mapping array elements of an array to another value.
A few SQL dialects, including ClickHouse, DuckDB, and Trino have introduced higher order functions with a lambda syntax to help implement features like this one. jOOQ can map a Java lambda to a SQL lambda, and emulate the feature using standard SQL functionality (using UNNEST and ARRAY_AGG) if the function isn't available.
SELECT array_map(ARRAY[1, 2, 2, 3], e -> square(e))
create.select(arrayMap(array(1, 2, 2, 3), DSL::square)).fetch();
The result would look like this:
+----------------+ | array_map | +----------------+ | [ 1, 4, 4, 9 ] | +----------------+
Dialect support
This example using jOOQ:
arrayMap(array(1, 2, 2, 3), DSL::square)
Translates to the following dialect specific expressions:
Aurora Postgres, Postgres
(
SELECT coalesce(
array_agg((e * e)),
CAST(ARRAY[] AS int[])
)
FROM UNNEST(ARRAY[1, 2, 2, 3]) t (e)
)
BigQuery
(
SELECT coalesce(
array_agg((e * e)),
CAST(ARRAY[] AS array<int64>)
)
FROM (
SELECT null e
FROM UNNEST([STRUCT(1 AS dual)]) AS dual
WHERE FALSE
UNION ALL
SELECT *
FROM UNNEST(ARRAY[1, 2, 2, 3]) t
) t
)
ClickHouse
arrayMap( e -> (e * e), ARRAY(1, 2, 2, 3) )
CockroachDB
(
SELECT coalesce(
array_agg((e * e)),
CAST(ARRAY[] AS int4[])
)
FROM UNNEST(ARRAY[1, 2, 2, 3]) t (e)
)
Databricks
transform( ARRAY(1, 2, 2, 3), e -> (e * e) )
DuckDB
array_transform( ARRAY[1, 2, 2, 3], e -> (e * e) )
H2, HSQLDB
(
SELECT coalesce(
array_agg((e * e)),
CAST(ARRAY[] AS int array)
)
FROM UNNEST(ARRAY[1, 2, 2, 3]) t (e)
)
Trino
transform( ARRAY[1, 2, 2, 3], e -> (e * e) )
ASE, Access, Aurora MySQL, DB2, Derby, Exasol, Firebird, Hana, Informix, MariaDB, MemSQL, MySQL, Oracle, Redshift, SQLDataWarehouse, SQLServer, SQLite, Snowflake, Sybase, Teradata, Vertica, YugabyteDB
/* UNSUPPORTED */
Generated with jOOQ 3.21. Support in older jOOQ versions may differ. Translate your own SQL on our website
Feedback
Do you have any feedback about this page? We'd love to hear it!