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Alexey 2021-04-03 19:31:24 +00:00
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20
docs/en/sql-reference/functions/string-functions.md
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@ -656,16 +656,14 @@ The function extracts text from HTML or XHTML according to the following rules.
1. Comments starting with `<!--` and ending with `-->` are removed.
1. The content of a `CDATA` section is left as is, without furthure processing.
1. `<script>` and `<style>` tags are removed with their content.
1. Other tags are removed from a text.
1. Whitespaces are removed or inserted in the extracted text. The following rules are applied to continuous text blocks.
- Leading and trailing whitespaces are removed from a text block.
- Consecutive whitespaces are collapsed to a single whitespace.
- Single whitespace is inserted between text blocks.
1. Text wrapped with `<script>` or `<style>` tags is removed entirely.
1. Any tag is replaced with a space.
1. Consecutive whitespaces (space, new line, line feed, tab characters) are converted to a single space.
1. Leading and trailing spaces are removed.
!!! info "Note"
It is not guaranteed that function entirely conforms to all HTML, XML or XHTML standards. But it tries to do the best.
HTML and XML entities are not decoded.
It is not guaranteed that the function fully supports all HTML, XML or XHTML standards. But it tries to do the best.
**Syntax**
@ -685,14 +683,13 @@ Type: [String](../../sql-reference/data-types/string.md).
**Example**
The first example contains tags and comment. Also note how whitespaces are processed.
The first example contains several tags and a comment and also shows whitespace processing.
The second example shows CDATA and script tag processing.
Query:
``` sql
SELECT extractTextFromHTML('<p> Text <i>inside</i><b>tags</b>. </p> <!-- comments -->');
SELECT extractTextFromHTML(' <p> Text <i>inside</i><b>tags</b>. <!-- comments --> </p> ');
SELECT extractTextFromHTML('<![CDATA[The content within <b>CDATA</b>]]> <script>alert("Script");</script>');
```
@ -700,6 +697,5 @@ Result:
``` text
Text inside tags .
The content within <b>CDATA</b>
```