CREATE TYPE
Creates a custom data type in the keyspace that contains one or more fields of related information, such as address (street, city, state, and postal code).
The scope of a user-defined type (UDT) is keyspace-wide.
UDTs cannot contain counter fields. |
See also: DROP TYPE
Syntax
CREATE TYPE [ IF NOT EXISTS ] [<keyspace_name>].<type_name> (<field_name> <cql_datatype> [ , <field_name> <cql_datatype> ... ]) ;
Syntax legend
Syntax conventions | Description |
---|---|
UPPERCASE |
Literal keyword. |
Lowercase |
Not literal. |
|
Variable value. Replace with a user-defined value. |
|
Optional.
Square brackets ( |
|
Group.
Parentheses ( |
|
Or.
A vertical bar ( |
|
Repeatable.
An ellipsis ( |
|
Single quotation ( |
|
Map collection.
Braces ( |
Set, list, map, or tuple.
Angle brackets ( |
|
|
End CQL statement.
A semicolon ( |
|
Separate the command line options from the command arguments with two hyphens ( |
|
Search CQL only: Single quotation marks ( |
|
Search CQL only: Identify the entity and literal value to overwrite the XML element in the schema and solrConfig files. |
Parameters
Parameter | Description | Default |
---|---|---|
|
Optional. Name of the keyspace that contains the table to index. |
If no name is specified, the current keyspace is used. |
|
Unique name for the type. CQL types are reserved for a list. See type names. |
|
|
Define fields that are in the UDT in a comma-separated list with |
|
|
Valid CQL data type. |
Usage notes
Once created, UDTs can be used either in a frozen or non-frozen state. In a frozen state, the UDT is stored as a single value, and cannot be altered or updated except as a whole. In a non-frozen state, the UDT is stored as a collection of fields, and can be updated individually.
Examples
Simple example
This example creates a user-defined type cycling.basic_info
that consists of personal data about an individual cyclist.
CREATE TYPE IF NOT EXISTS cycling.basic_info (
birthday timestamp,
nationality text,
height text,
weight text
);
DESCRIBE TYPE cycling.basic_info;
After defining the UDT, you can create a table that has columns with the UDT. CQL collection columns and other columns support the use of user-defined types, as shown in Inserting UDTs.
Example with TTL
This example creates a user-defined type (UDT) cycling.basic_info_withTTL
that consists of personal data about an individual cyclist, which includes the next_race
column that will be set with a timestamp and time-to-live (TTL).
CREATE TYPE IF NOT EXISTS cycling.basic_info_expire (
birthday timestamp,
nationality text,
height text,
weight text,
next_race text
);
DESCRIBE TYPE cycling.basic_info_expire;
To insert an entire row of data into a table using a timestamp and TTL, specify the values with an INSERT
command:
INSERT INTO cycling.basic_info_TTL_expire (
id, lastname, basics
) VALUES (
e7ae5cf3-d358-4d99-b900-85902fda9bb0,
'FRAME',
{
birthday : '1993-06-18',
nationality : 'New Zealand',
weight : '175',
height : '72',
next_race : 'Amgen Tour of California'
}
)
USING TIMESTAMP 100 AND TTL 10000;
To insert a single UDT value with a TTL, use a UPDATE
command:
UPDATE cycling.basic_info_TTL_expire USING TTL 100
SET basics = {
birthday : '1993-06-18',
nationality : 'New Zealand',
weight : '175',
height : '72',
next_race : 'Tour de France'
}
WHERE id = e7ae5cf3-d358-4d99-b900-85902fda9bb0;
To check the write time and TTL values of a UDT use the WRITETIME and TTL functions in a SELECT
command:
SELECT WRITETIME(basics), TTL(basics) FROM cycling.basic_info_TTL_expire
WHERE id = e7ae5cf3-d358-4d99-b900-85902fda9bb0;
Results
writetime(basics) | ttl(basics)
-------------------+-------------
1719859468740059 | 98
(1 rows)
It is important to note that you cannot use selection function writeTime
on non-frozen UDT basics.
This is because the UDT is not frozen and the write time is not stored with the UDT.
A string with a single quote in a UDT |