JSON_KEYS
Applies to ✅ Open Source Edition ✅ Express Edition ✅ Professional Edition ✅ Enterprise Edition
The JSON_KEYS function is a non-standard JSON function inspired by MySQL's JSON_KEYS function, which can be used to extract keys of a JSON object into an JSON array.
SELECT json_keys(json_object( KEY 'a' VALUE 1 KEY 'b' VALUE 2 ))
create.select(jsonKeys(jsonObject(
key("a").value(1),
key("b").value(2))))
.fetch();
The result would look like this:
+-----------+ | json_keys | +-----------+ | ["a","b"] | +-----------+
Dialect support
This example using jOOQ:
jsonKeys(jsonObject(key("a").value(1), key("b").value(2)))
Translates to the following dialect specific expressions:
-- AURORA_POSTGRES, POSTGRES, YUGABYTEDB
(
SELECT coalesce(
json_agg(j),
json_build_array()
)
FROM json_object_keys(json_build_object(
'a', CAST(1 AS int),
'b', CAST(2 AS int)
)) as j(j)
)
-- COCKROACHDB
(
SELECT coalesce(
json_agg(j),
json_build_array()
)
FROM json_object_keys(json_build_object(
'a', CAST(1 AS int4),
'b', CAST(2 AS int4)
)) as j(j)
)
-- MARIADB
json_keys(json_merge_preserve(
'{}',
json_object('a', 1),
json_object('b', 2)
))
-- MYSQL
json_keys(json_object(
'a', 1,
'b', 2
))
-- ORACLE
json_keys(json_object(
KEY 'a' VALUE nvl(NULL, 1),
KEY 'b' VALUE nvl(NULL, 2)
))
-- SNOWFLAKE
object_keys(object_construct_keep_null(
'a', 1,
'b', 2
))
-- SQLITE
(
SELECT json_group_array("key")
FROM json_each(json_object(
'a', 1,
'b', 2
))
)
-- TRINO
CAST(map_keys(cast(CAST(map_from_entries(ARRAY[
row(
'a',
CAST(1 AS json)
),
row(
'b',
CAST(2 AS json)
)
]) AS json) as map(varchar, json))) AS json)
-- ACCESS, ASE, AURORA_MYSQL, BIGQUERY, DB2, DERBY, DUCKDB, EXASOL, FIREBIRD, H2, HANA, HSQLDB, INFORMIX, MEMSQL,
-- REDSHIFT, SQLDATAWAREHOUSE, SQLSERVER, SYBASE, TERADATA, VERTICA
/* UNSUPPORTED */
(These are currently generated with jOOQ 3.19, see #10141), or translate your own on our website
Feedback
Do you have any feedback about this page? We'd love to hear it!