Finds the value a subdomain value from a valid URL. Input values must be of URL or String type.
In this implementation, a subdomain value is the first group of characters in the URL after any protocol identifiers ( http:// or https://, for example).
- For more information, see Structure of a URL .
- You can also extract domain values by function. See DOMAIN Function.
Basic Usage
URL literal example:
derive type:single value: SUBDOMAIN('http://www.example.com' ) as: 'myDomain'
Output: Generates a column containing the value www.
derive type:single value: SUBDOMAIN('http://www.exampl.e.com') as: 'myDomain'
Output: Generates a column containing the value www.exampl.
Column reference example:
derive type:single value: SUBDOMAIN(myURLs) as: 'myDomain'
Output: Generates the new myDomain column containing the subdomain values extracted from the myURLs column.
Syntax and Arguments
derive type:single value: SUBDOMAIN(column_url)
| Argument | Required? | Data Type | Description |
|---|---|---|---|
| column_url | Y | string | Name of column or String or URL literal containing the sub-domain value to extract |
For more information on syntax standards, see Language Documentation Syntax Notes.
column_url
Name of the column or URL or String literal whose values are used to extract the subdomain value.
- Missing input values generate missing results.
- Multiple columns and wildcards are not supported.
Usage Notes:
| Required? | Data Type | Example Value |
|---|---|---|
| Yes | String literal or column reference (URL) | http://www.example.com |
Tip: For additional examples, see Common Tasks.
Examples
Example - Domain, Subdomain, Host, and Suffix functions
DOMAIN- extracts the domain value from a URL. See DOMAIN Function.SUBDOMAIN- extracts the first group after the protocol identifier and before the domain value. See SUBDOMAIN Function.HOST- returns the complete value of the host from an URL. See HOST Function.SUFFIX- extracts the suffix of a URL. See SUFFIX Function.URLPARAMS- extracts the query parameters and values from a URL. See URLPARAMS Function.FILTEROBJECT- filters an Object value to show only the elements for a specified key. See FILTEROBJECT Function.
Source:
Your dataset includes the following values for URLs:
| URL |
|---|
| www.example.com |
| example.com/support |
| http://www.example.com/products/ |
| http://1.2.3.4 |
| https://www.example.com/free-download |
| https://www.example.com/about-us/careers |
| www.app.example.com |
| www.some.app.example.com |
| some.app.example.com |
| some.example.com |
| example.com |
| http://www.example.com?q1=broken%20record |
| http://www.example.com?query=khakis&app=pants |
| http://www.example.com?q1=broken%20record&q2=broken%20tape&q3=broken%20wrist |
Transform:
When the above data is imported into the application, the column is recognized as a URL. All values are registered as valid, even the IPv4 address.
To extract the domain and subdomain values:
derive type:single value: DOMAIN(URL) as: 'domain_URL'
derive type:single value: SUBDOMAIN(URL) as:'subdomain_URL'
derive type:single value: HOST(URL) as:host_URL'
derive type:single value: SUFFIX(URL) as:'suffix_URL'
You can use the Alteryx® pattern in the following transform to extract protocol identifiers, if present, into a new column:
extract col:URL on:`{start}%*://`
To clean this up, you might want to rename the column to protocol_URL.
To extract the path values, you can use the following regular expression:
NOTE: Regular expressions are considered a developer-level method for pattern matching. Please use them with caution. See Text Matching.
extract col: URL on: /[^*:\/\/]\/.*$/
The above transform grabs a little too much of the URL. If you rename the column to path_URL, you can use the following regular expression to clean it up:
extract col:path_URL on:/[!^\/].*$/
Delete the path_URL column and rename the path_URL1 column to the deleted one. Then:
derive type:single value: URLPARAMS(URL) as: 'urlParams'
If you wanted to just see the values for the q1 parameter, you could add the following:
derive type:single value: FILTEROBJECT(urlParams,'q1') as: 'urlParam_q1'
Results:
For display purposes, the results table has been broken down into separate sets of columns.
Column set 1:
| URL | host_URL | path_URL |
|---|---|---|
| www.example.com | www.example.com | |
| example.com/support | example.com | /support |
| http://www.example.com/products/ | www.example.com | /products/ |
| http://1.2.3.4 | 1.2.3.4 | |
| https://www.example.com/free-download | www.example.com | /free-download |
| https://www.example.com/about-us/careers | www.example.com | /about-us/careers |
| www.app.example.com | www.app.example.com | |
| www.some.app.example.com | www.some.app.example.com | |
| some.app.example.com | some.app.example.com | |
| some.example.com | some.example.com | |
| example.com | example.com | |
| http://www.example.com?q1=broken%20record | www.example.com | |
| http://www.example.com?query=khakis&app=pants | www.example.com | |
| http://www.example.com?q1=broken%20record&q2=broken%20tape&q3=broken%20wrist | www.example.com |
Column set 2:
| URL | protocol_URL | subdomain_URL | domain_URL | suffix_URL |
|---|---|---|---|---|
| www.example.com | www | example | com | |
| example.com/support | example | com | ||
| http://www.example.com/products/ | http:// | www | example | com |
| http://1.2.3.4 | http:// | |||
| https://www.example.com/free-download | https:// | www | example | com |
| https://www.example.com/about-us/careers | https:// | www | example | com |
| www.app.example.com | www.app | example | com | |
| www.some.app.example.com | www.some.app | example | com | |
| some.app.example.com | some.app | example | com | |
| some.example.com | some | example | com | |
| example.com | example | com | ||
| http://www.example.com?q1=broken%20record | http:// | www | example | com |
| http://www.example.com?query=khakis&app=pants | http:// | www | example | com |
| http://www.example.com?q1=broken%20record&q2=broken%20tape&q3=broken%20wrist | http:// | www | example | com |
Column set 3:
| URL | urlParams | urlParam_q1 |
|---|---|---|
| www.example.com | ||
| example.com/support | ||
| http://www.example.com/products/ | ||
| http://1.2.3.4 | ||
| https://www.example.com/free-download | ||
| https://www.example.com/about-us/careers | ||
| www.app.example.com | ||
| www.some.app.example.com | ||
| some.app.example.com | ||
| some.example.com | ||
| example.com | ||
| http://www.example.com?q1=broken%20record | {"q1":"broken record"} | {"q1":"broken record"} |
| http://www.example.com?query=khakis&app=pants | {"query":"khakis","app":"pants"} | |
| http://www.example.com?q1=broken%20record&q2=broken%20tape&q3=broken%20wrist | {"q1":"broken record", "q2":"broken tape", "q3":"broken wrist"} | {"q1":"broken record"} |
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