SubField() is used to extract substring components from a parent string field, where the original record fields consist of two or more parts separated by a delimiter.
The Subfield() function can be used, for example, to extract first name and surname from a list of records consisting of full names, the component parts of a path name, or for extracting data from comma-separated tables.
If you use the Subfield() function in a LOAD statement with the optional field_no parameter left out, one full record will be generated for each substring. If several fields are loaded using Subfield() the Cartesian products of all combinations are created.
Syntax:
SubField(text,
delimiter[, field_no ])
Return data type: string
Arguments:
Arguments
Argument
Description
text
The original string. This can be a hard-coded text, a variable, a dollar-sign expansion, or another expression.
delimiter
A character within the input text that divides the string into component parts.
field_no
The optional third argument is an integer that specifies which of the substrings of the parent string text is to be returned. Use the value 1 to return the first substring, 2 to return the second substring, and so on.
If field_no is a positive value, substrings are extracted from left to right.
If field_no is a negative value, substrings are extracted from right to left.
Tip noteSubField() can be used instead of using complex combinations of functions such as Len(), Right(), Left(), Mid(), and other string functions.
Examples: Chart expressions
Example
Result
SubField(S,
';' ,2)
Returns 'cde'
if S is 'abc;cde;efg'.
SubField(S,
';' ,1)
Returns an empty string if S is an empty string.
SubField(S,
';' ,1)
Returns an empty string if S is ';'.
Suppose you have a variable that holds a path name vMyPath,
Set vMyPath=\Users\ext_jrb\Documents\Qlik\Sense\Apps;.
In a text & image chart, you can add a measure such as: SubField(vMyPath, '\',-3), which results in 'Qlik', because it is the substring third from the right-hand end of the variable vMyPath.
Examples: Script and chart expressions using SubField
Basic examples
Example
Result
SubField(S,
';' ,2)
Returns 'cde'
if S is 'abc;cde;efg'.
SubField(S,
';' ,1)
Returns an empty string if S is an empty string.
SubField(S,
';' ,1)
Returns an empty string if S is ';'.
Suppose you have a variable that holds a path name vMyPath,
Set vMyPath=\Users\ext_jrb\Documents\Qlik\Sense\Apps;.
In a text & image chart, you can add a measure such as: SubField(vMyPath, '\',-3), which results in 'Qlik', because it is the substring third from the right-hand end of the variable vMyPath.
Script example 1
Load script
Load the following script expressions and data in the data load editor.
FullName:
LOAD * inline [
Name
'Dave Owen'
'Joe Tem'
];
SepNames:
Load Name,
SubField(Name, ' ',1) as FirstName,
SubField(Name, ' ',-1) as Surname
Resident FullName;
Drop Table FullName;
Create a visualization
Create a table visualization in a Qlik Sensesheet with Name, FirstName, and SurName as dimensions.
Result
Name
FirstName
SurName
Dave Owen
Dave
Owen
Joe Tem
Joe
Tem
Explanation
The SubField() function extracts the first substring of Name by setting the field_no argument to 1. Since the value of field_no is positive, a left to right order is followed for extracting the subtring. A second function call extracts the second substring by setting the field_no argument to -1, which extracts the substring following a right to left order.
Script example 2
Load script
Load the following script expressions and data in the data load editor.
LOAD DISTINCT
Instrument,
SubField(Player,',') as Player,
SubField(Project,',') as Project;
Load * inline [
Instrument|Player|Project
Guitar|Neil,Mike|Music,Video
Guitar|Neil|Music,OST
Synth|Neil,Jen|Music,Video,OST
Synth|Jo|Music
Guitar|Neil,Mike|Music,OST
] (delimiter is '|');
Create a visualization
Create a table visualization in a Qlik Sense sheet with Instrument, Player, and Project as dimensions.
Result
Instrument
Player
Project
Guitar
Mike
Music
Guitar
Mike
Video
Guitar
Mike
OST
Guitar
Neil
Music
Guitar
Neil
Video
Guitar
Neil
OST
Synth
Jen
Music
Synth
Jen
Video
Synth
Jen
OST
Synth
Jo
Music
Synth
Neil
Music
Synth
Neil
Video
Synth
Neil
OST
Explanation
This example shows how using multiple instances of the Subfield() function, each with the field_no parameter left out, from within the same LOAD statement creates Cartesian products of all combinations. The DISTINCT option is used to avoid creating duplicate records.
Variable
A variable in Qlik Sense is a container storing a static value or a calculation, for example a numeric or alphanumeric value.
A measure is a calculation base on one ore more aggregations. For example, the sum of sales is a single aggregation, while the sum of sales divided by the count of customers is a measure based on two aggregations.
A measure is a calculation base on one ore more aggregations. For example, the sum of sales is a single aggregation, while the sum of sales divided by the count of customers is a measure based on two aggregations.
Sheets are components of Qlik Sense apps. They present visualizations to app users so they can explore, analyze, and discover data. Sheets can be public or private.
A dimension is an entity used to categorize data in a chart. For example, the slices in a pie chart or the bars of a bar chart represent individual values in a dimension. Dimensions are often a single field with discrete values, but can also be calculated in an expression.
A dimension is a dataset in a data mart that forms part of the star schema. Dimension datasets hold the descriptive information for all related fields that are included in the fact table’s records. A few common examples of dimension datasets are Customer and Product. Since the data in a dimension dataset is often denormalized, dimension datasets have a large number of columns.
