UUID
Notice: Some of the examples below are referenced from ClickHouse Documentation but have been adapted and modified to work in ByConity.
generateUUIDv4
Generates the UUID of version 4 .
Syntax
generateUUIDv4()
Returned value
- The UUID type value.
Examples This example demonstrates creating a table with the UUID type column and inserting a value into the table.
CREATE TABLE test.functionGenerateUUIDv4 (x UUID) ENGINE=CnchMergeTree ORDER BY x;
INSERT INTO test.functionGenerateUUIDv4 SELECT generateUUIDv4();
SELECT * FROM test.functionGenerateUUIDv4;
┌─x────────────────────────────────────┐
│ a630fbcb-1a32-4902-b5cc-dd51eba8cf4b │
└──────────────────────────────────────┘
toUUID
Converts String type value to UUID type. Exception will be raised if input string is invalid uuid format.
Syntax
toUUID(String)
Arguments
String— string in uuid format.
Returned value
- The UUID type value.
Examples
SELECT toUUID('61f0c404-5cb3-11e7-907b-a6006ad3dba0') AS uuid, toTypeName(uuid) AS uuid_type;
┌─uuid─────────────────────────────────┬─uuid_type─┐
│ 61f0c404-5cb3-11e7-907b-a6006ad3dba0 │ UUID │
└──────────────────────────────────────┴───────────┘
toUUIDOrNull
It takes an argument of type String and tries to parse it into UUID. If failed, returns NULL.
Syntax
toUUIDOrNull(String)
Arguments
String— string in uuid format.
Returned value
- The Nullable(UUID) type value.
Examples
SELECT toUUIDOrNull('61f0c404-5cb3-11e7-907b-a6006ad3dba0T') AS uuid
┌─uuid─┐
│ ᴺᵁᴸᴸ │
└──────┘
toUUIDOrZero
It takes an argument of type String and tries to parse it into UUID. If failed, returns zero UUID.
Syntax
toUUIDOrZero(String)
Arguments
String— string in uuid format.
Returned value
- The UUID type value.
Examples
SELECT toUUIDOrZero('61f0c404-5cb3-11e7-907b-a6006ad3dba0T') AS uuid
┌─uuid─────────────────────────────────┐
│ 00000000-0000-0000-0000-000000000000 │
└──────────────────────────────────────┘
generateUUIDv4
Generates the UUID of version 4 .
Syntax
generateUUIDv4()
Returned value
The UUID type value.
Usage example
This example demonstrates creating a table with the UUID type column and inserting a value into the table.
CREATE TABLE t_uuid (x UUID) ENGINE=TinyLog
INSERT INTO t_uuid SELECT generateUUIDv4()
SELECT * FROM t_uuid
┌────────────────────────────────────x─┐
│ f4bf890f-f9dc-4332-ad5c-0c18e73f28e9 │
└──────────────────────────────────────┘
toUUID
Syntax
toUUID (x)
Converts String type value to UUID type.
toUUID(String)
Returned value
The UUID type value.
Usage example
SELECT toUUID('61f0c404-5cb3-11e7-907b-a6006ad3dba0') AS uuid
┌─────────────────────────────────uuid─┐
│ 61f0c404-5cb3-11e7-907b-a6006ad3dba0 │
└──────────────────────────────────────┘
toUUIDOrNull
toUUIDOrNull (x)
It takes an argument of type String and tries to parse it into UUID. If failed, returns NULL.
toUUIDOrNull(String)
Returned value
The Nullable(UUID) type value.
Usage example
SELECT toUUIDOrNull('61f0c404-5cb3-11e7-907b-a6006ad3dba0T') AS uuid
┌─uuid─┐
│ ᴺᵁᴸᴸ │
└──────┘
toUUIDOrZero
toUUIDOrZero (x)
It takes an argument of type String and tries to parse it into UUID. If failed, returns zero UUID.
toUUIDOrZero(String)
Returned value
The UUID type value.
Usage example
SELECT toUUIDOrZero('61f0c404-5cb3-11e7-907b-a6006ad3dba0T') AS uuid
┌─────────────────────────────────uuid─┐
│ 00000000-0000-0000-0000-000000000000 │
└──────────────────────────────────────┘