INCLUDE_NULL_VALUES directive
Applies to ✅ Open Source Edition ✅ Express Edition ✅ Professional Edition ✅ Enterprise Edition
The INCLUDE_NULL_VALUES directive allows for including NULL values in the output document.
By default, NULL values are omitted from the FOR JSON document output. Consider this query:
SELECT id, nullif(cd, 'en') AS cd FROM langauge ORDER BY id FOR JSON AUTO
create.select(
LANGUAGE.ID,
nullif(LANGUAGE.CD, "en").as(LANGUAGE.CD))
.from(LANGUAGE)
.orderBy(LANGUAGE.ID)
.forJSON().auto()
.fetch();
This query produces a document like this:
[
{"id":1},
{"id":2,"cd":"de"},
{"id":3,"cd":"fr"},
{"id":4,"cd":"pt"}
]
If you prefer explicit NULL values, write:
SELECT id, nullif(cd, 'en') AS cd FROM langauge ORDER BY id FOR JSON AUTO, INCLUDE_NULL_VALUES
create.select(
LANGUAGE.ID,
nullif(LANGUAGE.CD, "en").as(LANGUAGE.CD))
.from(LANGUAGE)
.orderBy(LANGUAGE.ID)
.forJSON().auto().includeNullValues()
.fetch();
This query produces a document like this:
[
{"id":1,"cd":null},
{"id":2,"cd":"de"},
{"id":3,"cd":"fr"},
{"id":4,"cd":"pt"}
]
Dialect support
This example using jOOQ:
select(BOOK.ID).from(BOOK).orderBy(BOOK.ID).forJSON().auto().includeNullValues()
Translates to the following dialect specific expressions:
Aurora Postgres, CockroachDB, Postgres, YugabyteDB
SELECT json_agg(json_build_object('ID', ID))
FROM (
SELECT BOOK.ID
FROM BOOK
ORDER BY BOOK.ID
) t
ClickHouse
SELECT toJSONString(CAST(groupArray(toJSONString(map('ID', ID))) AS Array(JSON)))
FROM (
SELECT BOOK.ID
FROM BOOK
ORDER BY BOOK.ID
) t
DB2
SELECT CAST(('[' || listagg(
json_object(
KEY 'ID' VALUE ID
NULL ON NULL
),
','
) || ']') AS varchar(32672))
FROM (
SELECT BOOK.ID
FROM BOOK
ORDER BY BOOK.ID
) t
H2
SELECT json_arrayagg(json_object( KEY 'ID' VALUE ID NULL ON NULL )) FROM ( SELECT BOOK.ID FROM BOOK ORDER BY BOOK.ID ) t
MariaDB, MySQL
SET @t = @@group_concat_max_len;
SET @@group_concat_max_len = 4294967295;
SELECT json_merge_preserve(
'[]',
concat(
'[',
group_concat(json_object('ID', ID) SEPARATOR ','),
']'
)
)
FROM (
SELECT BOOK.ID
FROM BOOK
ORDER BY BOOK.ID
) t;
SET @@group_concat_max_len = @t;
Oracle
SELECT json_arrayagg(json_object( KEY 'ID' VALUE ID NULL ON NULL RETURNING clob ) FORMAT JSON RETURNING clob) FROM ( SELECT BOOK.ID FROM BOOK ORDER BY BOOK.ID ) t
SQLServer
SELECT ( SELECT BOOK.ID FROM BOOK ORDER BY BOOK.ID FOR JSON AUTO, INCLUDE_NULL_VALUES )
Trino
SELECT cast(array_agg(CAST(map_from_entries(ARRAY[row( 'ID', CAST(ID AS json) )]) AS json)) AS json) FROM ( SELECT BOOK.ID FROM BOOK ORDER BY BOOK.ID ) t
ASE, Access, Aurora MySQL, BigQuery, Databricks, Derby, DuckDB, Exasol, Firebird, HSQLDB, Hana, Informix, MemSQL, Redshift, SQLDataWarehouse, SQLite, Snowflake, Sybase, Teradata, Vertica
/* UNSUPPORTED */
Generated with jOOQ 3.21. Support in older jOOQ versions may differ. Translate your own SQL on our website
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