SUBDOMAIN Function

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, seeStructure of a URL.
You can also extract domain values by function. See DOMAIN Function.

Wrangle vs. SQL: This function is part of Wrangle, a proprietary data transformation language. Wrangle is not SQL. For more information, see Wrangle Language.

Basic Usage

URL literal example:

subdomain('<span class="nolink">http://www.example.com</span>')

Output: Returns the value: www.

subdomain('<span class="nolink">http://www.exampl.e.com</span>')

Output: Returns the value: www.exampl.

Column reference example:

subdomain(myURLs)

Output: Returns the subdomain values extracted from the myURLs column.

Syntax and Arguments

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

Examples

Tipp

For additional examples, see Common Tasks.

Example - Domain, Subdomain, Host, and Suffix functions

This examples illustrates how you can extract component parts of a URL using specialized functions for the URL data type.

Functions:

Item	Description
DOMAIN Function	Finds the value for the domain from a valid URL. Input values must be of URL or String type.
SUBDOMAIN Function	Finds the value a subdomain value from a valid URL. Input values must be of URL or String type.
HOST Function	Finds the host value from a valid URL. Input values must be of URL or String type and can be literals or column references.
SUFFIX Function	Finds the suffix value after the domain from a valid URL. Input values must be of URL or String type.
URLPARAMS Function	Extracts the query parameters of a URL into an Object. The Object keys are the parameter's names, and its values are the parameter's values. Input values must be of URL or String type.
FILTEROBJECT Function	Filters the keys and values from an Object data type column based on a specified key value.

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

Transformation:

When the above data is imported into the application, the column is recognized as a URL. All values are registered as valid, even the numeric address.

To extract the domain and subdomain values:

Transformation Name	`New formula`
Parameter: Formula type	Single row formula
Parameter: Formula	DOMAIN(URL)
Parameter: New column name	'domain_URL'

Transformation Name	`New formula`
Parameter: Formula type	Single row formula
Parameter: Formula	SUBDOMAIN(URL)
Parameter: New column name	'subdomain_URL'

Transformation Name	`New formula`
Parameter: Formula type	Single row formula
Parameter: Formula	HOST(URL)
Parameter: New column name	'host_URL'

Transformation Name	`New formula`
Parameter: Formula type	Single row formula
Parameter: Formula	SUFFIX(URL)
Parameter: New column name	'suffix_URL'

You can use the Wrangle in the following transformation to extract protocol identifiers, if present, into a new column:

Transformation Name	`Extract text or pattern`
Parameter: Column to extract from	URL
Parameter: Option	Custom text or pattern
Parameter: Text to extract	`{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:

Anmerkung

Regular expressions are considered a developer-level method for pattern matching. Please use them with caution. See Text Matching.

Transformation Name	`Extract text or pattern`
Parameter: Column to extract from	URL
Parameter: Option	Custom text or pattern
Parameter: Text to extract	/[^:\/\/]\/.$/

The above transformation 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:

Transformation Name	`Extract text or pattern`
Parameter: Column to extract from	URL
Parameter: Option	Custom text or pattern
Parameter: Text to extract	/[!^\/].*$/

Delete the path_URL column and rename the path_URL1 column to the deleted one. Then:

Transformation Name	`New formula`
Parameter: Formula type	Single row formula
Parameter: Formula	URLPARAMS(URL)
Parameter: New column name	'urlParams'

If you wanted to just see the values for the q1 parameter, you could add the following:

Transformation Name	`New formula`
Parameter: Formula type	Single row formula
Parameter: Formula	FILTEROBJECT(urlParams,'q1')
Parameter: New column name	'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"}

In diesem Abschnitt: