# lower — DuckDB 1.3.2

Converts `string` to lower case

- Reference: /products/haybarn/functions/releases/duckdb-1.3.2/lower/
- JSON: /products/haybarn/functions/api/v1/duckdb-1.3.2/functions/lower.json
- Snapshot ID: duckdb-1.3.2
- Engine: duckdb v1.3.2
- Source ID: 0b83e5d2f6
- Binary SHA-256: 9a2ae2a4d5dbd07a5b0cb30c502d65014825d34924c681eb3faa7647e7cd2b6f
- Captured: 2026-09-05T18:37:33.818Z
- Source: https://github.com/duckdb/duckdb/releases/tag/v1.3.2
- Loaded extensions: autocomplete, core_functions, icu, json, parquet, shell

## Interpretation

- Choose a snapshot matching the target engine and build. The default is captured from the published Haybarn WASM package used by the browser playground. Historical native snapshots are also available.
- Availability is an observation in the recorded build and extension profile, not a guarantee of support in every installation or in WASM.
- Types and descriptions are declarations from duckdb_functions(). Binding can specialize result types. Null means not supplied by the catalog; do not invent defaults, optionality, argument mode, or table output columns.
- Raw parameter arrays preserve catalog order for scalar/aggregate/macro functions. Raw table arguments are alphabetical. Use callingConvention for engine-confirmed positional order and named arguments; null modes are unrecorded. Named does not mean optional. Macro defaults and special named variadic behavior are not supplied by duckdb_functions().
- Catalog examples are source material and may require data or extensions. runnableExamples contains separately verified SQL for the pinned WASM package; sample-data adaptations and guide examples are labeled separately.
- Guide annotations and recipes are separate editorial content. The browser runner always uses Haybarn WASM 1.5.5-rc3, independently of the documentation snapshot.
- All URLs beginning with / are relative to the origin hosting this document. Exports require no JavaScript, cookies, API key, or browser engine.

## Overloads

### overload-8fa36a5165f1d342

Kind: scalar. Parameter order: catalog-order.

```text
lower(string: VARCHAR) → VARCHAR
```

Link: /products/haybarn/functions/releases/duckdb-1.3.2/lower/#overload-8fa36a5165f1d342

| Argument | Catalog type | Calling mode |
| --- | --- | --- |
| string | VARCHAR | not recorded |

Declared return type: VARCHAR. Variadic argument type: none declared.
Stability: CONSISTENT. Declared side effects: false.


## Guide recipes

### Turn a label into a useful key.

Trim the edges, normalize case, and replace runs of spaces. Small functions compose into a readable cleaning step.

Intended runtime: Haybarn WASM 1.5.5-rc3. Per-example execution verification: not recorded in this export.

```sql
SELECT regexp_replace(
  lower(trim('  Summer Harvest 2026  ')),
  '\s+', '-', 'g'
) AS slug;
```

## Engine catalog examples

Source examples may require additional data or extensions. Expressions are wrapped in SELECT; execution verification is not recorded.

Reported for: overload-8fa36a5165f1d342

```sql
SELECT lower('Hello');
```

## Runnable examples

Executed successfully in Haybarn WASM 1.5.5-rc3. Sample data and guide examples are separate from the original catalog.

```sql
SELECT lower('Hello');
```

## Additional DuckDB documentation

- [List Functions](https://duckdb.org/docs/current/sql/functions/list#list-comprehension)
- [Text Functions](https://duckdb.org/docs/current/sql/functions/text#lowerstring)
- [Text Functions](https://duckdb.org/docs/current/sql/functions/text.html#lowerstring)

## In other engines

### BigQuery: to_hex()



BigQuery:

```sql
TO_HEX(x)
```

Haybarn / DuckDB:

```sql
LOWER(HEX(x))
```

Translation from [SQLGlot](https://github.com/tobymao/sqlglot/blob/3086608e6fd4c41c02dfba47171608d2b193fce2/tests/dialects/test_bigquery.py#L1115).

### Snowflake: uuid_string()

Uses lower as part of a larger rewrite.

Snowflake:

```sql
UUID_STRING('fe971b24-9572-4005-b22f-351e9c09274d', 'foo')
```

Haybarn / DuckDB:

```sql
(SELECT LOWER(SUBSTRING(h, 1, 8) || '-' || SUBSTRING(h, 9, 4) || '-' || '5' || SUBSTRING(h, 14, 3) || '-' || FORMAT('{:02x}', CAST('0x' || SUBSTRING(h, 17, 2) AS INT) & 63 | 128) || SUBSTRING(h, 19, 2) || '-' || SUBSTRING(h, 21, 12)) FROM (SELECT SUBSTRING(SHA1(UNHEX(REPLACE('fe971b24-9572-4005-b22f-351e9c09274d', '-', '')) || ENCODE('foo')), 1, 32) AS h))
```

Translation from [SQLGlot](https://github.com/tobymao/sqlglot/blob/3086608e6fd4c41c02dfba47171608d2b193fce2/tests/dialects/test_snowflake.py#L2294).

## Observed availability

| Snapshot | Observed | Overloads | JSON |
| --- | --- | --- | --- |
| haybarn-1.5.5-rc3 | present | 1 | [reference](/products/haybarn/functions/api/v1/haybarn-1.5.5-rc3/functions/lower.json) |
| duckdb-1.5.5 | present | 1 | [reference](/products/haybarn/functions/api/v1/duckdb-1.5.5/functions/lower.json) |
| duckdb-1.4.4 | present | 1 | [reference](/products/haybarn/functions/api/v1/duckdb-1.4.4/functions/lower.json) |
| duckdb-1.3.2 | present | 1 | [reference](/products/haybarn/functions/api/v1/duckdb-1.3.2/functions/lower.json) |

Engine catalog documentation is derived from MIT-licensed Haybarn and DuckDB. [Notices](/third-party-notices.txt).