UUID and time-based UUID data types
The driver provides ways to generate and decode UUIDs and time-based UUID.
Uuid
The Uuid
class provides support for representing Cassandra uuid data type. To generate a version 4 unique identifier,
use the Uuid
static method random()
:
const Uuid = require('cassandra-driver').types.Uuid;
const id = Uuid.random();
The driver decodes Cassandra uuid data type values as an instances of Uuid.
client.execute('SELECT id FROM users')
.then(function (result) {
console.log(result.rows[0].id instanceof Uuid); // true
console.log(result.rows[0].id.toString()); // xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
});
You can also parse a string representation of a uuid into a Uuid instance:
const id = Uuid.fromString(stringValue);
console.log(id instanceof Uuid); // true
console.log(id.toString() === stringValue); // true
TimeUuid
The TimeUuid
class provides support for representing Cassandra timeuuid data type.
To generate a time-based identifier, you can use the now()
and fromDate()
static methods:
const TimeUuid = require('cassandra-driver').types.TimeUuid;
const id1 = TimeUuid.now();
const id2 = TimeUuid.fromDate(new Date());
The driver decodes CQL timeuuid data type values as instances of TimeUuid
.
client.execute('SELECT id, timeid FROM sensor')
.then(function (result) {
console.log(result.rows[0].timeid instanceof TimeUuid); // true
console.log(result.rows[0].timeid instanceof Uuid); // true, it inherits from Uuid
console.log(result.rows[0].timeid.toString()); // <- xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
console.log(result.rows[0].timeid.getDate()); // <- Date stored in the identifier
});
You can specify the other parts of the identifier, such as the node and the clock sequence, or the 100-nanosecond
precision value of the date using the optional parameters in fromDate()
method.
const ticks = 9123; // A number from 0 to 9999
const id = TimeUuid.fromDate(new Date(), ticks, node, clock);