Inserting or updating data into a user-defined type (UDT)
How to insert or update data into a user-defined type (UDT).
If a table specifies a user-defined type (UDT) to hold data,
then either INSERT
or UPDATE
is used to enter
data.
Procedure
Inserting data into a UDT
-
Set or replace user-defined type data, using the
INSERT
orUPDATE
command, and enclosing the user-defined type with curly brackets, separating each key-value pair in the user-defined type by a colon.cqlsh> INSERT INTO cycling.cyclist_stats (id, lastname, basics) VALUES ( e7ae5cf3-d358-4d99-b900-85902fda9bb0, 'FRAME', { birthday : '1993-06-18', nationality : 'New Zealand', weight : null, height : null } );
Note: Note the inclusion of null values for UDT elements that have no value. A value, whether null or otherwise, must be included for each element of the UDT. -
Data can be inserted into a UDT that is nested in another
column type. For example, a list of
races, where the race name, date, and time are defined
in a UDT has elements enclosed in curly brackets that are
in turn enclosed in square brackets.
cqlsh> INSERT INTO cycling.cyclist_races (id, lastname, firstname, races) VALUES ( 5b6962dd-3f90-4c93-8f61-eabfa4a803e2, 'VOS', 'Marianne', [{ race_title : 'Rabobank 7-Dorpenomloop Aalburg',race_date : '2015-05-09',race_time : '02:58:33' }, { race_title : 'Ronde van Gelderland',race_date : '2015-04-19',race_time : '03:22:23' }] );
Note: The UDT nested in the list is frozen, so the entire list will be read when querying the table.
Updating individual field data in a UDT
-
In Cassandra 3.6 and later, user-defined types that include only non-collection
fields can update individual field values. Update an individual field in
user-defined type data using the
UPDATE
command. The desired key-value pair are defined in the command. In order to update, the UDT must be defined in theCREATE TABLE
command as an unfrozen data type.cqlsh> CREATE TABLE cycling.cyclist_stats ( id UUID, lastname text, basics basic_info, PRIMARY KEY (id) ); INSERT INTO cycling.cyclist_stats (id, lastname, basics) VALUES (220844bf-4860-49d6-9a4b-6b5d3a79cbfb, 'TIRALONGO', { birthday:'1977-07-08',nationality:'Italy',weight:'63 kg',height:'1.78 m' }); UPDATE cyclist_stats SET basics.birthday = '2000-12-12' WHERE id = 220844bf-4860-49d6-9a4b-6b5d3a79cbfb;
The UDT is defined in the table with
basics basic_info
. This example shows an inserted row, followed by an update that only updates the value ofbirthday
inside the UDTbasics
.cqlsh:cycling> SELECT * FROM cycling.cyclist_stats WHERE id = 220844bf-4860-49d6-9a4b-6b5d3a79cbfb; id | basics | lastname --------------------------------------+--------------------------------------------------------------------------------------------------------+----------- 220844bf-4860-49d6-9a4b-6b5d3a79cbfb | {birthday: '2000-12-12 08:00:00.000000+0000', nationality: 'Italy', weight: '63 kg', height: '1.78 m'} | TIRALONGO
The resulting change is evident, as is the unchanged values for nationality, weight, and height.Note: UDTs with collection fields must be frozen in table creation, and individual field values cannot be updated.