# UUID

`UUID` stores a universally unique identifier. Text input is parsed as a UUID and displayed using its canonical lowercase, hyphenated spelling.

## Syntax

```text
UUID
```

Invalid UUID text raises `TYPE_MISMATCH`. UUID values support equality, ordering, grouping and indexes. They are identifiers rather than numeric operands; direct numeric arithmetic and numeric aggregates reject them.

Use `gen_random_uuid()` for a random version 4 UUID or `uuidv7()` for a time-ordered version 7 UUID. These functions produce native UUID values.

## Usage Example

### Normalizing UUID text

```sql
SELECT CAST('550E8400-E29B-41D4-A716-446655440000' AS UUID)
FORMAT csv;
```

```text
"550e8400-e29b-41d4-a716-446655440000"
```

### Using a UUID key

```sql
CREATE TABLE documents(id UUID PRIMARY KEY, title String);
INSERT INTO documents VALUES
    ('550e8400-e29b-41d4-a716-446655440000', 'Project notes');
```

```sql
SELECT title
FROM documents
WHERE id = '550e8400-e29b-41d4-a716-446655440000'
FORMAT csv;
```

```text
"Project notes"
```

### Checking a generated UUID version

```sql
SELECT uuid_extract_version(gen_random_uuid()),
       uuid_extract_version(uuidv7())
FORMAT csv;
```

```text
4,7
```

See [UUID functions](https://coordinatordb.com/docs/reference/functions/regular-functions/uuid-functions) for generation, version extraction and timestamp extraction.