Functions for Working with URLs

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

    Extracts the protocol from a URL.

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

    domain

    Extracts the hostname from a URL.

    Arguments

    • — URL. Type: .

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

    1. svn+ssh://some.svn-hosting.com:80/repo/trunk
    2. some.svn-hosting.com:80/repo/trunk
    3. https://yandex.com/time/

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

    1. some.svn-hosting.com
    2. some.svn-hosting.com
    3. yandex.com

    Returned values

    • Empty string. If ClickHouse can’t parse the input string as a URL.

    Type: String.

    Example

    1. SELECT domain('svn+ssh://some.svn-hosting.com:80/repo/trunk');
    1. ┌─domain('svn+ssh://some.svn-hosting.com:80/repo/trunk')─┐
    2. │ some.svn-hosting.com                                   │
    3. └────────────────────────────────────────────────────────┘

    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.

    1. topLevelDomain(url)

    Arguments

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

    1. svn+ssh://some.svn-hosting.com:80/repo/trunk
    2. some.svn-hosting.com:80/repo/trunk
    3. https://yandex.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

    1. SELECT topLevelDomain('svn+ssh://www.some.svn-hosting.com:80/repo/trunk');
    1. ┌─topLevelDomain('svn+ssh://www.some.svn-hosting.com:80/repo/trunk')─┐
    2. │ com                                                                │
    3. └────────────────────────────────────────────────────────────────────┘

    firstSignificantSubdomain

    Returns the “first significant subdomain”. This is a non-standard concept specific to Yandex.Metrica. 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.yandex.ru/’) = ‘yandex’, firstSignificantSubdomain (‘https://news.yandex.com.tr/’) = ‘yandex’. 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.yandex.com.tr/') = 'yandex.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:

    • cutToFirstSignificantSubdomain('https://news.yandex.com.tr/') = 'yandex.com.tr'.
    • .
    • cutToFirstSignificantSubdomain('tr') = ''.

    cutToFirstSignificantSubdomainCustom

    Returns the part of the domain that includes top-level subdomains up to the first significant subdomain. Accepts custom name.

    Can be useful if you need fresh TLD list or you have custom.

    Configuration example:

    Syntax

    1. cutToFirstSignificantSubdomain(URL, TLD)
    • URL — URL. String.
    • TLD — Custom TLD list name. .

    Returned value

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

    Type: String.

    Example

    Query:

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

    Result:

    1. ┌─cutToFirstSignificantSubdomainCustom('bar.foo.there-is-no-such-domain', 'public_suffix_list')─┐
    2. │ foo.there-is-no-such-domain                                                                   │
    3. └───────────────────────────────────────────────────────────────────────────────────────────────┘

    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:

    1. <!-- <top_level_domains_path>/var/lib/clickhouse/top_level_domains/</top_level_domains_path> -->
    2. <top_level_domains_lists>
    3.     <!-- https://publicsuffix.org/list/public_suffix_list.dat -->
    4.     <public_suffix_list>public_suffix_list.dat</public_suffix_list>
    5.     <!-- NOTE: path is under top_level_domains_path -->
    6. </top_level_domains_lists>

    Syntax

      Parameters

      • URL — URL. .
      • 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.

      Type: .

      Example

      Query:

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

      Result:

      1. ┌─cutToFirstSignificantSubdomainCustomWithWWW('www.foo', 'public_suffix_list')─┐
      2. │ www.foo                                                                      │
      3. └──────────────────────────────────────────────────────────────────────────────┘

      See Also

      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:

      1. <!-- <top_level_domains_path>/var/lib/clickhouse/top_level_domains/</top_level_domains_path> -->
      2. <top_level_domains_lists>
      3.     <!-- https://publicsuffix.org/list/public_suffix_list.dat -->
      4.     <public_suffix_list>public_suffix_list.dat</public_suffix_list>
      6. </top_level_domains_lists>

      Syntax

      Parameters

      • URL — URL. .
      • TLD — Custom TLD list name. String.

      Returned value

      • First significant subdomain.

      Type: .

      Example

      Query:

      1. SELECT firstSignificantSubdomainCustom('bar.foo.there-is-no-such-domain', 'public_suffix_list');
      1. ┌─firstSignificantSubdomainCustom('bar.foo.there-is-no-such-domain', 'public_suffix_list')─┐
      2. │ foo                                                                                      │
      3. └──────────────────────────────────────────────────────────────────────────────────────────┘

      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.

      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. Example: the function is used to implement tree reports the URL in Yandex. Metric.

      1. URLPathHierarchy('https://example.com/browse/CONV-6788') =
      2. [
      3.     '/browse/',
      4.     '/browse/CONV-6788'
      5. ]

      decodeURLComponent(URL)

      Returns the decoded URL.
      Example:

      1. SELECT decodeURLComponent('http://127.0.0.1:8123/?query=SELECT%201%3B') AS DecodedURL;
      1. ┌─DecodedURL─────────────────────────────┐
      2. │ http://127.0.0.1:8123/?query=SELECT 1; │
      3. └────────────────────────────────────────┘

      netloc

      Extracts network locality (username:[[email protected]](https://clickhouse.com/cdn-cgi/l/email-protection):port) from a URL.

      Syntax

      1. netloc(URL)

      Arguments

      • url — URL. .

      Returned value

      • username:[[email protected]](https://clickhouse.com/cdn-cgi/l/email-protection):port.

      Type: String.

      Example

      Query:

      1. SELECT netloc('http://[email protected]:80/');

      Result:

      1. ┌─netloc('http://[email protected]:80/')─┐
      2. │ [email protected]: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.