Creating Data Islands in QlikView using Data Source

Data Islands

Sometimes you want to create a link between two tables where no link exists.  A table that does not have any associations to other tables is called ‘Data Island’.  You can create a link between two tables with Concat () function.

Data islands can be created from any data source and are often created as an inline table. Data islands can be used to refer dates, table headers, or whatever you need to disconnect from most of the existing data in the data model.

One useful example of data islands is to aid in the construction of table charts in the presentation layer of the document, for instance, to allow you to create rows containing measured values rather than dimensions. Let’s use a call center example where we track customer representative telephone calls and call times. In the script, you load an inline table named call table with an inline load statement and one column, metrics. In this table you will specify three records: call quantity, call duration, and call center productivity, as shown in the following code:

[call table]:
LOAD  * INLINE  [
Metrics
Call quantity
Call duration
Call center productivity
];

Then, we can add some data about the call center, via an inline load:
Call center, via an inline

Load:
[call center log]:
LOAD  * INLINE [
Date id,    calls,
Call-time-minutes
1,  1000, 200
2,  1500, 300
3,  2000, 400
];

From this point, it’s a matter of creating a list box in the front-end of qlik view, and selecting the dimensions name of metrics from the field list in the list box properties general tab. This will create the list box with the three measures you would like to report. The expression for this list box is dependent on the corresponding row in the data island. In this table, the expression can be set by clicking on the add button in the expression tab and entering the following expression:

If (metrics  = “call quantity”,
Sum(calls), if (metrics =
“call duration”,
Sum (call-time-minutes),
Sum(calls)/sum (call-time-minutes)))

The preceding code will sum up all calls if the metric name is equal to call quantity. If the metric name is call duration, the row will display the sum of the call time minutes. If the row is anything else (call center productivity, in this case), the row will display the sum of all calls divided by the sum of call time minutes.