> ## Documentation Index
> Fetch the complete documentation index at: https://docs.paradedb.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Regex

<Danger>
  **Legacy Docs:** This page describes our legacy API. It will be deprecated in
  a future version. Please use the [v2 API](/) where possible.
</Danger>

Finds documents containing terms that match a specific regex pattern.

## Regex Syntax

ParadeDB supports all regex constructs of the Rust [regex](https://docs.rs/regex/latest/regex/) crate, with the following exceptions:

1. Lazy quantifiers such as `+?`
2. Word boundaries such as `\b`

Otherwise, the full syntax of the [regex](https://docs.rs/regex/latest/regex/) crate is supported, including all Unicode support and relevant flags.

A list of regex flags and grouping options can be [found here](https://docs.rs/regex/latest/regex/#grouping-and-flags), which includes:

* named and numbered capture groups
* case insensitivity flag (`i`)
* multi-line mode (`m`)

## Basic Usage

<CodeGroup>
  ```sql Function Syntax theme={null}
  SELECT description, rating, category
  FROM mock_items
  WHERE id @@@ paradedb.regex('description', '(plush|leather)');
  ```

  ```sql JSON Syntax theme={null}
  SELECT description, rating, category
  FROM mock_items
  WHERE id @@@
  '{
      "regex": {
          "field": "description",
          "pattern": "(plush|leather)"
      }
  }'::jsonb;
  ```
</CodeGroup>

<div className="mt-8" />

<ParamField body="field" required>
  Specifies the field within the document to search for the term.
</ParamField>

<ParamField body="pattern" required>
  A regex pattern string.
</ParamField>

## Wildcard Query

The following query finds all documents that match a wildcard pattern.

<CodeGroup>
  ```sql Function Syntax theme={null}
  SELECT description, rating, category
  FROM mock_items
  WHERE id @@@ paradedb.regex('description', 'key.*rd');
  ```

  ```sql JSON Syntax theme={null}
  SELECT description, rating, category
  FROM mock_items
  WHERE id @@@
  '{
      "regex": {
          "field": "description",
          "pattern": "key.*rd"
      }
  }'::jsonb;
  ```
</CodeGroup>