---
title: ULID Functions reference
meta:
    description: Functions for working with ULID.
headingMaxLevels: 2
---

# Functions for Working with ULID

These functions allow you to generate and extract information from Universally Unique Lexicographically Sortable Identifiers (ULIDs).

## generateULID

Generates a new Universally Unique Lexicographically Sortable Identifier (ULID). ULIDs are designed to be sortable by time and are 26 characters long.

### Syntax

```sql
generateULID([x])
```

### Arguments

- `x`: Any data type. This optional argument is used to ensure a new ULID is generated if the function is called multiple times within a single query, preventing common subexpression elimination.

### Returns

A `FixedString(26)` value representing the newly generated ULID.

### Example

```sql
SELECT generateULID()
```

Result:

```result
┌─generateULID()─────────────┐
│ 01H00000000000000000000000 │
└────────────────────────────┘
```

## ULIDStringToDateTime

Extracts the timestamp component embedded within a ULID string.

### Syntax

```sql
ULIDStringToDateTime(ulid[, timezone])
```

### Arguments

- `ulid`: `String` or `FixedString(26)`. The ULID string from which to extract the timestamp.
- `timezone`: `String`. An optional timezone name to apply to the returned `DateTime64` value.

### Returns

A `DateTime64(3)` value representing the timestamp from the ULID, with millisecond precision.

### Example

```sql
SELECT ULIDStringToDateTime('01GNB2S2FGN2P93QPXDNB4EN2R')
```

Result:

```result
┌─ULIDStringToDateTime('01GNB2S2FGN2P93QPXDNB4EN2R')─┐
│                            2022-12-28 00:40:37.616 │
└────────────────────────────────────────────────────┘
```