## TO_LOWER

The `TO_LOWER` function in ES|QL is used to convert an input string to lower case.

### Syntax

`TO_LOWER(str)`

#### Parameters

- `str`: String expression. If null, the function returns null.

### Examples

Here are a couple of examples of how you can use the `TO_LOWER` function in ES|QL queries:

```esql
ROW message = "HELLO WORLD"
| EVAL lower_message = TO_LOWER(message)
```

In this example, the `TO_LOWER` function is used to convert the string "HELLO WORLD" to lower case. The result would be "hello world".

```esql
ROW name = "John Doe"
| EVAL lower_name = TO_LOWER(name)
```

In this example, the `TO_LOWER` function is used to convert the string "John Doe" to lower case. The result would be "john doe".