Dual() combines a number and a string into a single record, such that the number representation of the record can be used for sorting and calculation purposes, while the string value can be used for display purposes
Syntax:
Dual(text, number)
Return data type: dual
Arguments:
| Argument | Description |
|---|---|
| text | The string value to be used in combination with the number argument. |
| number | The number to be used in combination with the string in the string argument. |
In QlikView, all field values are potentially dual values. This means that the field values can have both a numeric value and a textual value. An example is a date that could have a numeric value of 40908 and the textual representation '2011-12-31'.
When several data items read into one field have different string representations but the same valid number representation, they will all share the first string representation encountered.
Example 1:
Add the following examples to your script and run it.
Load dual ( NameDay,NumDay ) as DayOfWeek inline
[ NameDay,NumDay
Monday,0
Tuesday,1
Wednesday,2
Thursday,3
Friday,4
Saturday,5
Sunday,6 ];
The field DayOfWeek can be used in a chart, as a dimension, for example.In a table with the week days are automatically sorted into their correct number sequence, instead of alphabetical order.
Example 2:
Load Dual('Q' & Ceil(Month(Now())/3), Ceil(Month(Now())/3)) as Quarter AutoGenerate 1;
This example finds the current quarter. It is displayed as Q1 when the Now() function is run in the first three months of the year, Q2 for the second three months, and so on. However, when used in sorting, the field Quarter will behave as its numerical value: 1 to 4.
Example 3:
Dual('Q' & Ceil(Month(Date)/3), Ceil(Month(Date)/3)) as Quarter
As in the previous example, the field Quarter is created with the text values 'Q1' to 'Q4', and assigned the numeric values 1 to 4. In order to use this in the script the values for Date must be loaded.
Example 4:
Dual(WeekYear(Date) & '-W' & Week(Date), WeekStart(Date)) as YearWeek
This example create sa field YearWeek with text values of the form '2012-W22' and at the same time, assigns a numeric value corresponding to the date number of the first day of the week, for example: 41057. In order to use this in the script the values for Date must be loaded.
