The JSONB
data type stores JSON (JavaScript Object Notation) data as a binary representation of the JSONB
value, which eliminates whitespace, duplicate keys, and key ordering. JSONB
supports inverted indexes.
Alias
In CockroachDB, JSON
is an alias for JSONB
.
JSONB
and JSON
are two different data types. In CockroachDB, the JSONB
/ JSON
data type is similar in behavior to the JSONB
data type in PostgreSQL. Considerations
- The primary key, foreign key, and unique constraints cannot be used on
JSONB
values. - A standard index cannot be created on a
JSONB
column; you must use an inverted index.
Syntax
The syntax for the JSONB
data type follows the format specified in RFC8259. A constant value of type JSONB
can be expressed using an interpreted literal or a string literal annotated with type JSONB
.
There are six types of JSONB
values:
null
- Boolean
- String
- Number (i.e.,
decimal
, not the standardint64
) - Array (i.e., an ordered sequence of
JSONB
values) - Object (i.e., a mapping from strings to
JSONB
values)
Examples:
'{"type": "account creation", "username": "harvestboy93"}'
'{"first_name": "Ernie", "status": "Looking for treats", "location" : "Brooklyn"}'
Size
The size of a JSONB
value is variable, but it's recommended to keep values under 1 MB to ensure performance. Above that threshold, write amplification and other considerations may cause significant performance degradation.
JSONB
Functions
Function | Description | Example |
---|---|---|
jsonb_array_elements(<jsonb>) | Expands a JSONB array to a set of JSONB values. | SELECT jsonb_array_elements('[1,true, 2,false]'); |
jsonb_build_object(<any_element>...) | Builds a JSONB object out of a variadic argument list that alternates between keys and values. | SELECT json_build_object('Zoo',1,'Enter',2); |
jsonb_each(<jsonb>) | Expands the outermost JSONB object into a set of key-value pairs. | SELECT * from json_each('{"a":"Apple", "b":"ball"}'); |
jsonb_object_keys(<jsonb>) | Returns sorted set of keys in the outermost JSONB object. | SELECT * from jsonb_object_keys('{"fb1":"abc123","fb2":{"fb3":"ant", "f4":"ball"}}'); |
jsonb_pretty(<jsonb>) | Returns the given JSONB value as a STRING indented and with newlines. | See the example below. |
For the full list of supported JSONB
functions, see Functions and Operators.
JSONB
Operators
Operator | Description | Example |
---|---|---|
-> | Access a JSONB field, returning a JSONB value. | SELECT '[{"foo":"bar"}]'::JSONB->0->'foo' = '"bar"'::JSONB; |
->> | Access a JSONB field, returning a string. | SELECT '{"foo":"bar"}'::JSONB->>'foo' = 'bar'::STRING; |
@> | Tests whether the left JSONB field contains the right JSONB field. | SELECT ('{"foo": {"baz": 3}, "bar": 2}'::JSONB @> '{"foo": {"baz":3}}'::JSONB ) = true; |
For the full list of supported JSONB
operators, see Functions and Operators.
Examples
Create a Table with a JSONB
Column
> CREATE TABLE users ( profile_id UUID PRIMARY KEY DEFAULT gen_random_uuid(), last_updated TIMESTAMP DEFAULT now(), user_profile JSONB );
> SHOW COLUMNS FROM users;
+--------------+-----------+-------------+-------------------+-----------------------+-------------+ | column_name | data_type | is_nullable | column_default | generation_expression | indices | +--------------+-----------+-------------+-------------------+-----------------------+-------------+ | profile_id | UUID | false | gen_random_uuid() | | {"primary"} | | last_updated | TIMESTAMP | true | now() | | {} | | user_profile | JSON | true | NULL | | {} | +--------------+-----------+-------------+-------------------+-----------------------+-------------+ (3 rows)
> INSERT INTO users (user_profile) VALUES ('{"first_name": "Lola", "last_name": "Dog", "location": "NYC", "online" : true, "friends" : 547}'), ('{"first_name": "Ernie", "status": "Looking for treats", "location" : "Brooklyn"}');
> SELECT * FROM users;
+--------------------------------------+----------------------------------+--------------------------------------------------------------------------+ | profile_id | last_updated | user_profile | +--------------------------------------+----------------------------------+--------------------------------------------------------------------------+ | 33c0a5d8-b93a-4161-a294-6121ee1ade93 | 2018-02-27 16:39:28.155024+00:00 | {"first_name": "Lola", "friends": 547, "last_name": "Dog", "location": | | | | "NYC", "online": true} | | 6a7c15c9-462e-4551-9e93-f389cf63918a | 2018-02-27 16:39:28.155024+00:00 | {"first_name": "Ernie", "location": "Brooklyn", "status": "Looking for | | | | treats"} | +--------------------------------------+----------------------------------+--------------------------------------------------------------------------+
Retrieve formatted JSONB
data
To retrieve JSONB
data with easier-to-read formatting, use the jsonb_pretty()
function. For example, retrieve data from the table you created in the first example:
> SELECT profile_id, last_updated, jsonb_pretty(user_profile) FROM users;
+--------------------------------------+----------------------------------+------------------------------------+ | profile_id | last_updated | jsonb_pretty | +--------------------------------------+----------------------------------+------------------------------------+ | 33c0a5d8-b93a-4161-a294-6121ee1ade93 | 2018-02-27 16:39:28.155024+00:00 | { | | | | "first_name": "Lola", | | | | "friends": 547, | | | | "last_name": "Dog", | | | | "location": "NYC", | | | | "online": true | | | | } | | 6a7c15c9-462e-4551-9e93-f389cf63918a | 2018-02-27 16:39:28.155024+00:00 | { | | | | "first_name": "Ernie", | | | | "location": "Brooklyn", | | | | "status": "Looking for treats" | | | | } | +--------------------------------------+----------------------------------+------------------------------------+
Retrieve specific fields from a JSONB
value
To retrieve a specific field from a JSONB
value, use the ->
operator. For example, retrieve a field from the table you created in the first example:
> SELECT user_profile->'first_name',user_profile->'location' FROM users;
+----------------------------+--------------------------+ | user_profile->'first_name' | user_profile->'location' | +----------------------------+--------------------------+ | "Lola" | "NYC" | | "Ernie" | "Brooklyn" | +----------------------------+--------------------------+
You can also use the ->>
operator to return JSONB
field values as STRING
values:
> SELECT user_profile->>'first_name', user_profile->>'location' FROM users;
+-----------------------------+---------------------------+ | user_profile->>'first_name' | user_profile->>'location' | +-----------------------------+---------------------------+ | Lola | NYC | | Ernie | Brooklyn | +-----------------------------+---------------------------+
For the full list of functions and operators we support, see Functions and Operators.
Create a table with a JSONB
column and a computed column
In this example, create a table with a JSONB
column and a computed column:
> CREATE TABLE student_profiles ( id STRING PRIMARY KEY AS (profile->>'id') STORED, profile JSONB );
Then, insert a few rows of data:
> INSERT INTO student_profiles (profile) VALUES ('{"id": "d78236", "name": "Arthur Read", "age": "16", "school": "PVPHS", "credits": 120, "sports": "none"}'), ('{"name": "Buster Bunny", "age": "15", "id": "f98112", "school": "THS", "credits": 67, "clubs": "MUN"}'), ('{"name": "Ernie Narayan", "school" : "Brooklyn Tech", "id": "t63512", "sports": "Track and Field", "clubs": "Chess"}');
> SELECT * FROM student_profiles;
+--------+---------------------------------------------------------------------------------------------------------------------+ | id | profile | +--------+---------------------------------------------------------------------------------------------------------------------+ | d78236 | {"age": "16", "credits": 120, "id": "d78236", "name": "Arthur Read", "school": "PVPHS", "sports": "none"} | | f98112 | {"age": "15", "clubs": "MUN", "credits": 67, "id": "f98112", "name": "Buster Bunny", "school": "THS"} | | t63512 | {"clubs": "Chess", "id": "t63512", "name": "Ernie Narayan", "school": "Brooklyn Tech", "sports": "Track and Field"} | +--------+---------------------------------------------------------------------------------------------------------------------+
The primary key id
is computed as a field from the profile
column.
Supported casting and conversion
JSONB
values can be cast to the following data type:
STRING