9.14. Fonctions UUID

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9.14. Fonctions UUID #

Tableau 9.45 shows the PostgreSQL functions that can be used to generate UUIDs.

Tableau 9.45. UUID Generation Functions

Function Description Example(s)
`gen_random_uuid` → `uuid` `uuidv4` → `uuid` Generate a version 4 (random) UUID. `gen_random_uuid()` → `5b30857f-0bfa-48b5-ac0b-5c64e28078d1` `uuidv4()` → `b42410ee-132f-42ee-9e4f-09a6485c95b8`
`uuidv7` ( [ `shift` `interval` ] ) → `uuid` Generate a version 7 (time-ordered) UUID. The timestamp is computed using UNIX timestamp with millisecond precision + sub-millisecond timestamp + random. The optional parameter `shift` will shift the computed timestamp by the given `interval`. `uuidv7()` → `019535d9-3df7-79fb-b466-fa907fa17f9e`

Function

Description

Example(s)

gen_random_uuid → uuid

uuidv4 → uuid

Generate a version 4 (random) UUID.

gen_random_uuid() → 5b30857f-0bfa-48b5-ac0b-5c64e28078d1

uuidv4() → b42410ee-132f-42ee-9e4f-09a6485c95b8

uuidv7 ( [ shift interval ] ) → uuid

Generate a version 7 (time-ordered) UUID. The timestamp is computed using UNIX timestamp with millisecond precision + sub-millisecond timestamp + random. The optional parameter shift will shift the computed timestamp by the given interval.

uuidv7() → 019535d9-3df7-79fb-b466-fa907fa17f9e

Note

The uuid-ossp module provides additional functions that implement other standard algorithms for generating UUIDs.

Tableau 9.46 shows the PostgreSQL functions that can be used to extract information from UUIDs.

Tableau 9.46. UUID Extraction Functions

Function Description Example(s)
`uuid_extract_timestamp` ( `uuid` ) → `timestamp with time zone` Extracts a `timestamp with time zone` from UUID version 1 and 7. For other versions, this function returns null. Note that the extracted timestamp is not necessarily exactly equal to the time the UUID was generated; this depends on the implementation that generated the UUID. `uuid_extract_timestamp('019535d9-3df7-79fb-b466-fa907fa17f9e'::uuid)` → `2025-02-23 21:46:24.503-05`
`uuid_extract_version` ( `uuid` ) → `smallint` Extracts the version from a UUID of the variant described by RFC 9562. For other variants, this function returns null. For example, for a UUID generated by `gen_random_uuid`, this function will return 4. `uuid_extract_version('41db1265-8bc1-4ab3-992f-885799a4af1d'::uuid)` → `4` `uuid_extract_version('019535d9-3df7-79fb-b466-fa907fa17f9e'::uuid)` → `7`

Function

Description

Example(s)

uuid_extract_timestamp ( uuid ) → timestamp with time zone

Extracts a timestamp with time zone from UUID version 1 and 7. For other versions, this function returns null. Note that the extracted timestamp is not necessarily exactly equal to the time the UUID was generated; this depends on the implementation that generated the UUID.

uuid_extract_timestamp('019535d9-3df7-79fb-b466-fa907fa17f9e'::uuid) → 2025-02-23 21:46:24.503-05

uuid_extract_version ( uuid ) → smallint

Extracts the version from a UUID of the variant described by RFC 9562. For other variants, this function returns null. For example, for a UUID generated by gen_random_uuid, this function will return 4.

uuid_extract_version('41db1265-8bc1-4ab3-992f-885799a4af1d'::uuid) → 4

uuid_extract_version('019535d9-3df7-79fb-b466-fa907fa17f9e'::uuid) → 7

PostgreSQL fournit aussi les opérateurs de comparaison habituels affichés dans Tableau 9.1 pour les UUID.

See Section 8.12 for details on the data type uuid in PostgreSQL.