> For the complete documentation index, see [llms.txt](https://mariadb.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mariadb.com/docs/server/server-usage/storage-engines/mroonga/mroonga-user-defined-functions/mroonga_highlight_html.md).

# mroonga\_highlight\_html

## Syntax

```
mroonga_highlight_html(text[[, query AS query]])

mroonga_highlight_html(text[[, keyword1, ..., keywordN]])
```

## Description

`mroonga_highlight_html` is a [user-defined function](/docs/server/server-usage/user-defined-functions.md) (UDF) included with the [Mroonga storage engine](/docs/server/server-usage/storage-engines/mroonga.md). It highlights the specified keywords in the target text. See [Creating Mroonga User-Defined Functions](/docs/server/server-usage/storage-engines/mroonga/mroonga-user-defined-functions/creating-mroonga-user-defined-functions.md) for details on creating this UDF if required.

The optional parameter can either be one or more *keywords*, or a Groonga *query*.

The function highlights the specified keywords in the target text by surrounding each keyword with `<span class="keyword">...</span>`, and escaping special HTML characters such as `<` and `>`.

Returns highlighted HTML.

## Examples

```sql
SELECT mroonga_highlight_html('<p>MariaDB includes the Mroonga storage engine</p>.') 
  AS highlighted_html;
+-----------------------------------------------------------------+
| highlighted_html                                                |
+-----------------------------------------------------------------+
| &lt;p&gt;MariaDB includes the Mroonga storage engine&lt;/p&gt;. |
+-----------------------------------------------------------------+
```

Highlighting the words `MariaDB` and `Mroonga` in a given text:

```sql
SELECT mroonga_highlight_html('MariaDB includes the Mroonga storage engine.', 'MariaDB', 'Mroonga') 
  AS highlighted_html;
+--------------------------------------------------------------------------------------------------------+
| highlighted_html                                                                                       |
+--------------------------------------------------------------------------------------------------------+
| <span class="keyword">MariaDB</span> includes the <span class="keyword">Mroonga</span> storage engine. |
+--------------------------------------------------------------------------------------------------------+
```

The same outcome, formulated as a Groonga query:

```sql
SELECT mroonga_highlight_html('MariaDB includes the Mroonga storage engine.', 'MariaDB OR Mroonga' 
  AS query) AS highlighted_text;
+--------------------------------------------------------------------------------------------------------+
| highlighted_text                                                                                       |
+--------------------------------------------------------------------------------------------------------+
| <span class="keyword">MariaDB</span> includes the <span class="keyword">Mroonga</span> storage engine. |
+--------------------------------------------------------------------------------------------------------+
```

## See Also

* [Creating Mroonga User-Defined Functions](/docs/server/server-usage/storage-engines/mroonga/mroonga-user-defined-functions/creating-mroonga-user-defined-functions.md)

<sub>*This page is licensed: CC BY-SA / Gnu FDL*</sub>

{% @marketo/form formId="4316" %}


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://mariadb.com/docs/server/server-usage/storage-engines/mroonga/mroonga-user-defined-functions/mroonga_highlight_html.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.