﻿---
title: LIKE and RLIKE operators
description: LIKE and RLIKE operators are commonly used to filter data based on string patterns. They usually act on a field placed on the left-hand side of the operator,...
url: https://www.elastic.co/elastic/docs-builder/docs/2437/reference/query-languages/sql/sql-like-rlike-operators
---

# LIKE and RLIKE operators
`LIKE` and `RLIKE` operators are commonly used to filter data based on string patterns. They usually act on a field placed on the left-hand side of the operator, but can also act on a constant (literal) expression. The right-hand side of the operator represents the pattern. Both can be used in the `WHERE` clause of the `SELECT` statement, but `LIKE` can also be used in other places, such as defining an [index pattern](https://www.elastic.co/elastic/docs-builder/docs/2437/reference/query-languages/sql/sql-index-patterns) or across various [SHOW commands](https://www.elastic.co/elastic/docs-builder/docs/2437/reference/query-languages/sql/sql-commands). This section covers only the `SELECT ... WHERE ...` usage.
<note>
  One significant difference between `LIKE`/`RLIKE` and the [full-text search predicates](https://www.elastic.co/elastic/docs-builder/docs/2437/reference/query-languages/sql/sql-functions-search) is that the former act on [exact fields](/elastic/docs-builder/docs/2437/reference/query-languages/sql/sql-data-types#sql-multi-field) while the latter also work on [analyzed](https://www.elastic.co/elastic/docs-builder/docs/2437/reference/elasticsearch/mapping-reference/text) fields. If the field used with `LIKE`/`RLIKE` doesn’t have an exact not-normalized sub-field (of [keyword](https://www.elastic.co/elastic/docs-builder/docs/2437/reference/elasticsearch/mapping-reference/keyword) type) Elasticsearch SQL will not be able to run the query. If the field is either exact or has an exact sub-field, it will use it as is, or it will automatically use the exact sub-field even if it wasn’t explicitly specified in the statement.
</note>


## `LIKE`

```sql
expression        
LIKE constant_exp 
```

**Description**: The SQL `LIKE` operator is used to compare a value to similar values using wildcard operators. There are two wildcards used in conjunction with the `LIKE` operator:
- The percent sign (%)
- The underscore (_)

The percent sign represents zero, one or multiple characters. The underscore represents a single number or character. These symbols can be used in combinations.
<note>
  No other characters have special meaning or act as wildcard. Characters often used as wildcards in other languages (`*` or `?`) are treated as normal characters.
</note>

```sql
SELECT author, name FROM library WHERE name LIKE 'Dune%';

    author     |     name
---------------+---------------
Frank Herbert  |Dune
Frank Herbert  |Dune Messiah
```

There is, also, the possibility of using an escape character if one needs to match the wildcard characters themselves. This can be done by using the `ESCAPE [escape_character]` statement after the `LIKE ...` operator:
```
SELECT name, author FROM library WHERE name LIKE 'Dune/%' ESCAPE '/';
```

In the example above `/` is defined as an escape character which needs to be placed before the `%` or `_` characters if one needs to match those characters in the pattern specifically. By default, there is no escape character defined.
<important>
  Even though `LIKE` is a valid option when searching or filtering in Elasticsearch SQL, full-text search predicates `MATCH` and `QUERY` are [faster and much more powerful and are the preferred alternative](#sql-like-prefer-full-text).
</important>


## `RLIKE`

```sql
expression         
RLIKE constant_exp 
```

**Description**: This operator is similar to `LIKE`, but the user is not limited to search for a string based on a fixed pattern with the percent sign (`%`) and underscore (`_`); the pattern in this case is a regular expression which allows the construction of more flexible patterns.
For supported syntax, see [*Regular expression syntax*](https://www.elastic.co/elastic/docs-builder/docs/2437/reference/query-languages/query-dsl/regexp-syntax).
```sql
SELECT author, name FROM library WHERE name RLIKE 'Child.* Dune';

    author     |      name
---------------+----------------
Frank Herbert  |Children of Dune
```

<important>
  Even though `RLIKE` is a valid option when searching or filtering in Elasticsearch SQL, full-text search predicates `MATCH` and `QUERY` are [faster and much more powerful and are the preferred alternative](#sql-like-prefer-full-text).
</important>


## Prefer full-text search predicates

When using `LIKE`/`RLIKE`, do consider using [full-text search predicates](https://www.elastic.co/elastic/docs-builder/docs/2437/reference/query-languages/sql/sql-functions-search) which are faster, much more powerful and offer the option of sorting by relevancy (results can be returned based on how well they matched).