Functions for Working with URLs

note

The functions mentioned in this section are optimized for maximum performance and for the most part do not follow the RFC-3986 standard. Functions which implement RFC-3986 have RFC appended to their function name and are generally slower.

You can generally use the non-RFC function variants when working with publicly registered domains that contain neither user strings nor @ symbols. The table below details which symbols in a URL can (✔) or cannot (✗) be parsed by the respective RFC and non-RFC variants:

Symbol	non-`RFC`	`RFC`
' '	✗	✗
\t	✗	✗
<	✗	✗
>	✗	✗
%	✗	✔*
{	✗	✗
}	✗	✗
\|	✗	✗
\\	✗	✗
^	✗	✗
~	✗	✔*
[	✗	✗
]	✗	✔
;	✗	✔*
=	✗	✔*
&	✗	✔*

symbols marked * are sub-delimiters in RFC 3986 and allowed for user info following the @ symbol.

Functions that Extract Parts of a URL

If the relevant part isn’t present in a URL, an empty string is returned.

protocol

Extracts the protocol from a URL.

Examples of typical returned values: http, https, ftp, mailto, tel, magnet.

domain

Extracts the hostname from a URL.

Syntax

domain(url)

Arguments

url — URL. String.

The URL can be specified with or without a protocol. Examples:

svn+ssh://some.svn-hosting.com:80/repo/trunk
some.svn-hosting.com:80/repo/trunk
https://clickhouse.com/time/

For these examples, the domain function returns the following results:

some.svn-hosting.com
some.svn-hosting.com
clickhouse.com

Returned values

Host name if the input string can be parsed as a URL, otherwise an empty string. String.

Example

SELECT domain('svn+ssh://some.svn-hosting.com:80/repo/trunk');

┌─domain('svn+ssh://some.svn-hosting.com:80/repo/trunk')─┐
│ some.svn-hosting.com                                   │
└────────────────────────────────────────────────────────┘

domainRFC

Extracts the hostname from a URL. Similar to domain, but RFC 3986 conformant.

Syntax

domainRFC(url)

Arguments

url — URL. String.

Returned values

Host name if the input string can be parsed as a URL, otherwise an empty string. String.

Example

SELECT
    domain('http://user:password@example.com:8080/path?query=value#fragment'),
    domainRFC('http://user:password@example.com:8080/path?query=value#fragment');

┌─domain('http://user:password@example.com:8080/path?query=value#fragment')─┬─domainRFC('http://user:password@example.com:8080/path?query=value#fragment')─┐
│                                                                           │ example.com                                                                  │
└───────────────────────────────────────────────────────────────────────────┴──────────────────────────────────────────────────────────────────────────────┘

domainWithoutWWW

Returns the domain without leading www. if present.

Syntax

domainWithoutWWW(url)

Arguments

url — URL. String.

Returned values

Domain name if the input string can be parsed as a URL (without leading www.), otherwise an empty string. String.

Example

SELECT domainWithoutWWW('http://paul@www.example.com:80/');

┌─domainWithoutWWW('http://paul@www.example.com:80/')─┐
│ example.com                                         │
└─────────────────────────────────────────────────────┘

domainWithoutWWWRFC

Returns the domain without leading www. if present. Similar to domainWithoutWWW but conforms to RFC 3986.

Syntax

domainWithoutWWWRFC(url)

Arguments

url — URL. String.

Returned values

Domain name if the input string can be parsed as a URL (without leading www.), otherwise an empty string. String.

Example

Query:

SELECT
    domainWithoutWWW('http://user:password@www.example.com:8080/path?query=value#fragment'),
    domainWithoutWWWRFC('http://user:password@www.example.com:8080/path?query=value#fragment');

Result:

┌─domainWithoutWWW('http://user:password@www.example.com:8080/path?query=value#fragment')─┬─domainWithoutWWWRFC('http://user:password@www.example.com:8080/path?query=value#fragment')─┐
│                                                                                         │ example.com                                                                                │
└─────────────────────────────────────────────────────────────────────────────────────────┴────────────────────────────────────────────────────────────────────────────────────────────┘

topLevelDomain

Extracts the the top-level domain from a URL.

topLevelDomain(url)

Arguments

url — URL. String.

note

The URL can be specified with or without a protocol. Examples:

svn+ssh://some.svn-hosting.com:80/repo/trunk
some.svn-hosting.com:80/repo/trunk
https://clickhouse.com/time/

Returned values

Domain name if the input string can be parsed as a URL. Otherwise, an empty string. String.

Example

Query:

SELECT topLevelDomain('svn+ssh://www.some.svn-hosting.com:80/repo/trunk');

Result:

┌─topLevelDomain('svn+ssh://www.some.svn-hosting.com:80/repo/trunk')─┐
│ com                                                                │
└────────────────────────────────────────────────────────────────────┘

topLevelDomainRFC

Extracts the the top-level domain from a URL. Similar to topLevelDomain, but conforms to RFC 3986.

topLevelDomainRFC(url)

Arguments

url — URL. String.

note

The URL can be specified with or without a protocol. Examples:

svn+ssh://some.svn-hosting.com:80/repo/trunk
some.svn-hosting.com:80/repo/trunk
https://clickhouse.com/time/

Returned values

Domain name if the input string can be parsed as a URL. Otherwise, an empty string. String.

Example

Query:

SELECT topLevelDomain('http://foo:foo%41bar@foo.com'), topLevelDomainRFC('http://foo:foo%41bar@foo.com');

Result:

┌─topLevelDomain('http://foo:foo%41bar@foo.com')─┬─topLevelDomainRFC('http://foo:foo%41bar@foo.com')─┐
│                                                │ com                                               │
└────────────────────────────────────────────────┴───────────────────────────────────────────────────┘

firstSignificantSubdomain

Returns the “first significant subdomain”. The first significant subdomain is a second-level domain for com, net, org, or co, otherwise it is a third-level domain. For example, firstSignificantSubdomain (‘https://news.clickhouse.com/’) = ‘clickhouse’, firstSignificantSubdomain (‘https://news.clickhouse.com.tr/’) = ‘clickhouse’. The list of "insignificant" second-level domains and other implementation details may change in the future.

Syntax

firstSignificantSubdomain(url)

Arguments

url — URL. String.

Returned value

The first significant subdomain. String.

Example

Query:

SELECT firstSignificantSubdomain('http://www.example.com/a/b/c?a=b')

Result:

┌─firstSignificantSubdomain('http://www.example.com/a/b/c?a=b')─┐
│ example                                                       │
└───────────────────────────────────────────────────────────────┘

firstSignificantSubdomainRFC

Syntax

firstSignificantSubdomainRFC(url)

Arguments

url — URL. String.

Returned value

The first significant subdomain. String.

Example

Query:

SELECT
    firstSignificantSubdomain('http://user:password@example.com:8080/path?query=value#fragment'),
    firstSignificantSubdomainRFC('http://user:password@example.com:8080/path?query=value#fragment');

Result:

┌─firstSignificantSubdomain('http://user:password@example.com:8080/path?query=value#fragment')─┬─firstSignificantSubdomainRFC('http://user:password@example.com:8080/path?query=value#fragment')─┐
│                                                                                              │ example                                                                                         │
└──────────────────────────────────────────────────────────────────────────────────────────────┴─────────────────────────────────────────────────────────────────────────────────────────────────┘

cutToFirstSignificantSubdomain

Returns the part of the domain that includes top-level subdomains up to the “first significant subdomain”.

Syntax

cutToFirstSignificantSubdomain(url)

Arguments

url — URL. String.

Returned value

Part of the domain that includes top-level subdomains up to the first significant subdomain if possible, otherwise returns an empty string. String.

Example

Query:

SELECT
    cutToFirstSignificantSubdomain('https://news.clickhouse.com.tr/'),
    cutToFirstSignificantSubdomain('www.tr'),
    cutToFirstSignificantSubdomain('tr');

Result:

┌─cutToFirstSignificantSubdomain('https://news.clickhouse.com.tr/')─┬─cutToFirstSignificantSubdomain('www.tr')─┬─cutToFirstSignificantSubdomain('tr')─┐
│ clickhouse.com.tr                                                 │ tr                                       │                                      │
└───────────────────────────────────────────────────────────────────┴──────────────────────────────────────────┴──────────────────────────────────────┘

cutToFirstSignificantSubdomainRFC

Returns the part of the domain that includes top-level subdomains up to the “first significant subdomain”. Similar to cutToFirstSignificantSubdomain but conforms to RFC 3986.

Syntax

cutToFirstSignificantSubdomainRFC(url)

Arguments

url — URL. String.

Returned value

Part of the domain that includes top-level subdomains up to the first significant subdomain if possible, otherwise returns an empty string. String.

Example

Query:

SELECT
    cutToFirstSignificantSubdomain('http://user:password@example.com:8080'),
    cutToFirstSignificantSubdomainRFC('http://user:password@example.com:8080');

Result:

┌─cutToFirstSignificantSubdomain('http://user:password@example.com:8080')─┬─cutToFirstSignificantSubdomainRFC('http://user:password@example.com:8080')─┐
│                                                                         │ example.com                                                                │
└─────────────────────────────────────────────────────────────────────────┴────────────────────────────────────────────────────────────────────────────┘

cutToFirstSignificantSubdomainWithWWW

Returns the part of the domain that includes top-level subdomains up to the "first significant subdomain", without stripping www.

Syntax

cutToFirstSignificantSubdomainWithWWW(url)

Arguments

url — URL. String.

Returned value

Part of the domain that includes top-level subdomains up to the first significant subdomain (with www) if possible, otherwise returns an empty string. String.

Example

Query:

SELECT
    cutToFirstSignificantSubdomainWithWWW('https://news.clickhouse.com.tr/'),
    cutToFirstSignificantSubdomainWithWWW('www.tr'),
    cutToFirstSignificantSubdomainWithWWW('tr');

Result:

┌─cutToFirstSignificantSubdomainWithWWW('https://news.clickhouse.com.tr/')─┬─cutToFirstSignificantSubdomainWithWWW('www.tr')─┬─cutToFirstSignificantSubdomainWithWWW('tr')─┐
│ clickhouse.com.tr                                                        │ www.tr                                          │                                             │
└──────────────────────────────────────────────────────────────────────────┴─────────────────────────────────────────────────┴─────────────────────────────────────────────┘

cutToFirstSignificantSubdomainWithWWWRFC

Returns the part of the domain that includes top-level subdomains up to the "first significant subdomain", without stripping www. Similar to cutToFirstSignificantSubdomainWithWWW but conforms to RFC 3986.

Syntax

cutToFirstSignificantSubdomainWithWWW(url)

Arguments

url — URL. String.

Returned value

Part of the domain that includes top-level subdomains up to the first significant subdomain (with "www") if possible, otherwise returns an empty string. String.

Example

Query:

SELECT
    cutToFirstSignificantSubdomainWithWWW('http:%2F%2Fwwwww.nova@mail.ru/economicheskiy'),
    cutToFirstSignificantSubdomainWithWWWRFC('http:%2F%2Fwwwww.nova@mail.ru/economicheskiy');

Result:

┌─cutToFirstSignificantSubdomainWithWWW('http:%2F%2Fwwwww.nova@mail.ru/economicheskiy')─┬─cutToFirstSignificantSubdomainWithWWWRFC('http:%2F%2Fwwwww.nova@mail.ru/economicheskiy')─┐
│                                                                                       │ mail.ru                                                                                  │
└───────────────────────────────────────────────────────────────────────────────────────┴──────────────────────────────────────────────────────────────────────────────────────────┘

cutToFirstSignificantSubdomainCustom

Returns the part of the domain that includes top-level subdomains up to the first significant subdomain. Accepts custom TLD list name. This function can be useful if you need a fresh TLD list or if you have a custom list.

Configuration example

<!-- <top_level_domains_path>/var/lib/clickhouse/top_level_domains/</top_level_domains_path> -->
<top_level_domains_lists>
    <!-- https://publicsuffix.org/list/public_suffix_list.dat -->
    <public_suffix_list>public_suffix_list.dat</public_suffix_list>
    <!-- NOTE: path is under top_level_domains_path -->
</top_level_domains_lists>

Syntax

cutToFirstSignificantSubdomain(url, tld)

Arguments

url — URL. String.
tld — Custom TLD list name. String.

Returned value

Part of the domain that includes top-level subdomains up to the first significant subdomain. String.

Example

Query:

SELECT cutToFirstSignificantSubdomainCustom('bar.foo.there-is-no-such-domain', 'public_suffix_list');

Result:

┌─cutToFirstSignificantSubdomainCustom('bar.foo.there-is-no-such-domain', 'public_suffix_list')─┐
│ foo.there-is-no-such-domain                                                                   │
└───────────────────────────────────────────────────────────────────────────────────────────────┘

See Also

firstSignificantSubdomain.

cutToFirstSignificantSubdomainCustomRFC

Syntax

cutToFirstSignificantSubdomainRFC(url, tld)

Arguments

url — URL. String.
tld — Custom TLD list name. String.

Returned value

Part of the domain that includes top-level subdomains up to the first significant subdomain. String.

See Also

firstSignificantSubdomain.

cutToFirstSignificantSubdomainCustomWithWWW

Returns the part of the domain that includes top-level subdomains up to the first significant subdomain without stripping www. Accepts custom TLD list name. It can be useful if you need a fresh TLD list or if you have a custom list.

Configuration example

<!-- <top_level_domains_path>/var/lib/clickhouse/top_level_domains/</top_level_domains_path> -->
<top_level_domains_lists>
    <!-- https://publicsuffix.org/list/public_suffix_list.dat -->
    <public_suffix_list>public_suffix_list.dat</public_suffix_list>
    <!-- NOTE: path is under top_level_domains_path -->
</top_level_domains_lists>

Syntax

cutToFirstSignificantSubdomainCustomWithWWW(url, tld)

Arguments

url — URL. String.
tld — Custom TLD list name. String.

Returned value

Part of the domain that includes top-level subdomains up to the first significant subdomain without stripping www. String.

Example

Query:

SELECT cutToFirstSignificantSubdomainCustomWithWWW('www.foo', 'public_suffix_list');

Result:

┌─cutToFirstSignificantSubdomainCustomWithWWW('www.foo', 'public_suffix_list')─┐
│ www.foo                                                                      │
└──────────────────────────────────────────────────────────────────────────────┘

See Also

firstSignificantSubdomain.

cutToFirstSignificantSubdomainCustomWithWWWRFC

Syntax

cutToFirstSignificantSubdomainCustomWithWWWRFC(url, tld)

Arguments

url — URL. String.
tld — Custom TLD list name. String.

Returned value

Part of the domain that includes top-level subdomains up to the first significant subdomain without stripping www. String.

See Also

firstSignificantSubdomain.

firstSignificantSubdomainCustom

Returns the first significant subdomain. Accepts customs TLD list name. Can be useful if you need fresh TLD list or you have custom.

Configuration example:

<!-- <top_level_domains_path>/var/lib/clickhouse/top_level_domains/</top_level_domains_path> -->
<top_level_domains_lists>
    <!-- https://publicsuffix.org/list/public_suffix_list.dat -->
    <public_suffix_list>public_suffix_list.dat</public_suffix_list>
    <!-- NOTE: path is under top_level_domains_path -->
</top_level_domains_lists>

Syntax

firstSignificantSubdomainCustom(url, tld)

Arguments

url — URL. String.
tld — Custom TLD list name. String.

Returned value

First significant subdomain. String.

Example

Query:

SELECT firstSignificantSubdomainCustom('bar.foo.there-is-no-such-domain', 'public_suffix_list');

Result:

┌─firstSignificantSubdomainCustom('bar.foo.there-is-no-such-domain', 'public_suffix_list')─┐
│ foo                                                                                      │
└──────────────────────────────────────────────────────────────────────────────────────────┘

See Also

firstSignificantSubdomain.

firstSignificantSubdomainCustomRFC

Returns the first significant subdomain. Accepts customs TLD list name. Can be useful if you need fresh TLD list or you have custom. Similar to firstSignificantSubdomainCustom but conforms to RFC 3986.

Syntax

firstSignificantSubdomainCustomRFC(url, tld)

Arguments

url — URL. String.
tld — Custom TLD list name. String.

Returned value

First significant subdomain. String.

See Also

firstSignificantSubdomain.

port

Returns the port or default_port if the URL contains no port or cannot be parsed.

Syntax

port(url [, default_port = 0])

Arguments

url — URL. String.
default_port — The default port number to be returned. UInt16.

Returned value

Port or the default port if there is no port in the URL or in case of a validation error. UInt16.

Example

Query:

SELECT port('http://paul@www.example.com:80/');

Result:

┌─port('http://paul@www.example.com:80/')─┐
│                                      80 │
└─────────────────────────────────────────┘

portRFC

Returns the port or default_port if the URL contains no port or cannot be parsed. Similar to port, but RFC 3986 conformant.

Syntax

portRFC(url [, default_port = 0])

Arguments

url — URL. String.
default_port — The default port number to be returned. UInt16.

Returned value

Port or the default port if there is no port in the URL or in case of a validation error. UInt16.

Example

Query:

SELECT
    port('http://user:password@example.com:8080'),
    portRFC('http://user:password@example.com:8080');

Result:

┌─port('http://user:password@example.com:8080')─┬─portRFC('http://user:password@example.com:8080')─┐
│                                             0 │                                             8080 │
└───────────────────────────────────────────────┴──────────────────────────────────────────────────┘

path

Returns the path without query string.

Example: /top/news.html.

pathFull

The same as above, but including query string and fragment.

Example: /top/news.html?page=2#comments.

queryString

Returns the query string without the initial question mark, # and everything after #.

Example: page=1&lr=213.

fragment

Returns the fragment identifier without the initial hash symbol.

queryStringAndFragment

Returns the query string and fragment identifier.

Example: page=1#29390.

extractURLParameter(url, name)

Returns the value of the name parameter in the URL, if present, otherwise an empty string is returned. If there are multiple parameters with this name, the first occurrence is returned. The function assumes that the parameter in the url parameter is encoded in the same way as in the name argument.

extractURLParameters(url)

Returns an array of name=value strings corresponding to the URL parameters. The values are not decoded.

extractURLParameterNames(url)

Returns an array of name strings corresponding to the names of URL parameters. The values are not decoded.

URLHierarchy(url)

Returns an array containing the URL, truncated at the end by the symbols /,? in the path and query-string. Consecutive separator characters are counted as one. The cut is made in the position after all the consecutive separator characters.

URLPathHierarchy(url)

The same as above, but without the protocol and host in the result. The / element (root) is not included.

URLPathHierarchy('https://example.com/browse/CONV-6788') =
[
    '/browse/',
    '/browse/CONV-6788'
]

encodeURLComponent(url)

Returns the encoded URL.

Example:

SELECT encodeURLComponent('http://127.0.0.1:8123/?query=SELECT 1;') AS EncodedURL;

┌─EncodedURL───────────────────────────────────────────────┐
│ http%3A%2F%2F127.0.0.1%3A8123%2F%3Fquery%3DSELECT%201%3B │
└──────────────────────────────────────────────────────────┘

decodeURLComponent(url)

Returns the decoded URL.

Example:

SELECT decodeURLComponent('http://127.0.0.1:8123/?query=SELECT%201%3B') AS DecodedURL;

┌─DecodedURL─────────────────────────────┐
│ http://127.0.0.1:8123/?query=SELECT 1; │
└────────────────────────────────────────┘

encodeURLFormComponent(url)

Returns the encoded URL. Follows rfc-1866, space( ) is encoded as plus(+).

Example:

SELECT encodeURLFormComponent('http://127.0.0.1:8123/?query=SELECT 1 2+3') AS EncodedURL;

┌─EncodedURL────────────────────────────────────────────────┐
│ http%3A%2F%2F127.0.0.1%3A8123%2F%3Fquery%3DSELECT+1+2%2B3 │
└───────────────────────────────────────────────────────────┘

decodeURLFormComponent(url)

Returns the decoded URL. Follows rfc-1866, plain plus(+) is decoded as space( ).

Example:

SELECT decodeURLFormComponent('http://127.0.0.1:8123/?query=SELECT%201+2%2B3') AS DecodedURL;

┌─DecodedURL────────────────────────────────┐
│ http://127.0.0.1:8123/?query=SELECT 1 2+3 │
└───────────────────────────────────────────┘

netloc

Extracts network locality (username:password@host:port) from a URL.

Syntax

netloc(url)

Arguments

url — URL. String.

Returned value

username:password@host:port. String.

Example

Query:

SELECT netloc('http://paul@www.example.com:80/');

Result:

┌─netloc('http://paul@www.example.com:80/')─┐
│ paul@www.example.com:80                   │
└───────────────────────────────────────────┘

Functions that remove part of a URL

If the URL does not have anything similar, the URL remains unchanged.

cutWWW

Removes leading www. (if present) from the URL’s domain.

cutQueryString

Removes query string, including the question mark.

cutFragment

Removes the fragment identifier, including the number sign.

cutQueryStringAndFragment

Removes the query string and fragment identifier, including the question mark and number sign.

cutURLParameter(url, name)

Removes the name parameter from a URL, if present. This function does not encode or decode characters in parameter names, e.g. Client ID and Client%20ID are treated as different parameter names.

Syntax

cutURLParameter(url, name)

Arguments

url — URL. String.
name — name of URL parameter. String or Array of Strings.

Returned value

url with name URL parameter removed. String.

Example

Query:

SELECT
    cutURLParameter('http://bigmir.net/?a=b&c=d&e=f#g', 'a') as url_without_a,
    cutURLParameter('http://bigmir.net/?a=b&c=d&e=f#g', ['c', 'e']) as url_without_c_and_e;

Result:

┌─url_without_a────────────────┬─url_without_c_and_e──────┐
│ http://bigmir.net/?c=d&e=f#g │ http://bigmir.net/?a=b#g │
└──────────────────────────────┴──────────────────────────┘

Functions for Working with URLs

Functions that Extract Parts of a URL​

protocol​

domain​

domainRFC​

domainWithoutWWW​

domainWithoutWWWRFC​

topLevelDomain​

topLevelDomainRFC​

firstSignificantSubdomain​

firstSignificantSubdomainRFC​

cutToFirstSignificantSubdomain​

cutToFirstSignificantSubdomainRFC​

cutToFirstSignificantSubdomainWithWWW​

cutToFirstSignificantSubdomainWithWWWRFC​

cutToFirstSignificantSubdomainCustom​

cutToFirstSignificantSubdomainCustomRFC​

cutToFirstSignificantSubdomainCustomWithWWW​

cutToFirstSignificantSubdomainCustomWithWWWRFC​

firstSignificantSubdomainCustom​

firstSignificantSubdomainCustomRFC​

port​

portRFC​

path​

pathFull​

queryString​

fragment​

queryStringAndFragment​

extractURLParameter(url, name)​

extractURLParameters(url)​

extractURLParameterNames(url)​

URLHierarchy(url)​

URLPathHierarchy(url)​

encodeURLComponent(url)​

decodeURLComponent(url)​

encodeURLFormComponent(url)​

decodeURLFormComponent(url)​

netloc​

Functions that remove part of a URL​

cutWWW​

cutQueryString​

cutFragment​

cutQueryStringAndFragment​

cutURLParameter(url, name)​

Functions that Extract Parts of a URL

protocol

domain

domainRFC

domainWithoutWWW

domainWithoutWWWRFC

topLevelDomain

topLevelDomainRFC

firstSignificantSubdomain

firstSignificantSubdomainRFC

cutToFirstSignificantSubdomain

cutToFirstSignificantSubdomainRFC

cutToFirstSignificantSubdomainWithWWW

cutToFirstSignificantSubdomainWithWWWRFC

cutToFirstSignificantSubdomainCustom

cutToFirstSignificantSubdomainCustomRFC

cutToFirstSignificantSubdomainCustomWithWWW

cutToFirstSignificantSubdomainCustomWithWWWRFC

firstSignificantSubdomainCustom

firstSignificantSubdomainCustomRFC

port

portRFC

path

pathFull

queryString

fragment

queryStringAndFragment

extractURLParameter(url, name)

extractURLParameters(url)

extractURLParameterNames(url)

URLHierarchy(url)

URLPathHierarchy(url)

encodeURLComponent(url)

decodeURLComponent(url)

encodeURLFormComponent(url)

decodeURLFormComponent(url)

netloc

Functions that remove part of a URL

cutWWW

cutQueryString

cutFragment

cutQueryStringAndFragment

cutURLParameter(url, name)