15 KiB
slug | sidebar_position | sidebar_label |
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/en/sql-reference/functions/url-functions | 200 | URLs |
Functions for Working with URLs
All these functions do not follow the RFC. They are maximally simplified for improved performance.
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.
domain(url)
Arguments
url
— URL. Type: String.
The URL can be specified with or without a scheme. 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 ClickHouse can parse the input string as a URL.
- Empty string. If ClickHouse can’t parse the input string as a URL.
Type: 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 │
└────────────────────────────────────────────────────────┘
domainWithoutWWW
Returns the domain and removes no more than one ‘www.’ from the beginning of it, if present.
topLevelDomain
Extracts the the top-level domain from a URL.
topLevelDomain(url)
Arguments
url
— URL. Type: String.
The URL can be specified with or without a scheme. 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 ClickHouse can parse the input string as a URL.
- Empty string. If ClickHouse cannot parse the input string as a URL.
Type: String
.
Example
SELECT topLevelDomain('svn+ssh://www.some.svn-hosting.com:80/repo/trunk');
┌─topLevelDomain('svn+ssh://www.some.svn-hosting.com:80/repo/trunk')─┐
│ com │
└────────────────────────────────────────────────────────────────────┘
firstSignificantSubdomain
Returns the “first significant subdomain”. The first significant subdomain is a second-level domain if it is ‘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.
cutToFirstSignificantSubdomain
Returns the part of the domain that includes top-level subdomains up to the “first significant subdomain” (see the explanation above).
For example:
cutToFirstSignificantSubdomain('https://news.clickhouse.com.tr/') = 'clickhouse.com.tr'
.cutToFirstSignificantSubdomain('www.tr') = 'tr'
.cutToFirstSignificantSubdomain('tr') = ''
.
cutToFirstSignificantSubdomainWithWWW
Returns the part of the domain that includes top-level subdomains up to the “first significant subdomain”, without stripping "www".
For example:
cutToFirstSignificantSubdomainWithWWW('https://news.clickhouse.com.tr/') = 'clickhouse.com.tr'
.cutToFirstSignificantSubdomainWithWWW('www.tr') = 'www.tr'
.cutToFirstSignificantSubdomainWithWWW('tr') = ''
.
cutToFirstSignificantSubdomainCustom
Returns the part of the domain that includes top-level subdomains up to the first significant subdomain. Accepts custom 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
cutToFirstSignificantSubdomainCustom(URL, TLD)
Arguments
Returned value
- Part of the domain that includes top-level subdomains up to the first significant subdomain.
Type: 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
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.
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
cutToFirstSignificantSubdomainCustomWithWWW(URL, TLD)
Arguments
Returned value
- Part of the domain that includes top-level subdomains up to the first significant subdomain without stripping
www
.
Type: String.
Example
Query:
SELECT cutToFirstSignificantSubdomainCustomWithWWW('www.foo', 'public_suffix_list');
Result:
┌─cutToFirstSignificantSubdomainCustomWithWWW('www.foo', 'public_suffix_list')─┐
│ www.foo │
└──────────────────────────────────────────────────────────────────────────────┘
See Also
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
Returned value
- First significant subdomain.
Type: 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
port(URL[, default_port = 0])
Returns the port or default_port
if there is no port in the URL (or in case of validation error).
path
Returns the path. Example: /top/news.html
The path does not include the query string.
pathFull
The same as above, but including query string and fragment. Example: /top/news.html?page=2#comments
queryString
Returns the query string. Example: page=1&lr=213. query-string does not include the initial question mark, as well as # and everything after #.
fragment
Returns the fragment identifier. fragment does not include 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. If there are many parameters with this name, it returns the first occurrence. This function works under the assumption that the parameter name is encoded in the URL exactly the same way as in the passed argument.
extractURLParameters(URL)
Returns an array of name=value strings corresponding to the URL parameters. The values are not decoded in any way.
extractURLParameterNames(URL)
Returns an array of name strings corresponding to the names of URL parameters. The values are not decoded in any way.
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
.
Type: 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 no more than one ‘www.’ from the beginning of the URL’s domain, if present.
cutQueryString
Removes query string. The question mark is also removed.
cutFragment
Removes the fragment identifier. The number sign is also removed.
cutQueryStringAndFragment
Removes the query string and fragment identifier. The question mark and number sign are also removed.
cutURLParameter(URL, name)
Removes the name
parameter from 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
Returned value
- URL with
name
URL parameter removed.
Type: 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 │
└──────────────────────────────┴──────────────────────────┘