Preceding Load is a very powerful functionality in QlikView in transforming the data.
What is Preceding load
It allows you to define multiple transformations and calculations within one load script which would otherwise will need to be created using separate load and resident load statements.
It takes input from the previous Select statement.
Preceding Load is invoked by checking the “preceding load ” while selecting the tables.
Another Advantage of Preceding Load is that it allows you to use QlikView functions in the Load script.
Let us see how your script will look when you don’t check the “preceding Load” while selecting the table.
Loading table without preceding load will not allow you to use QlikView functions.
Now let us check “Preceding load” and see how the load script changes and what advantages it brings.
In this script you can see that preceding load takes the input from the previous Select Statement. You can select all the columns in the Select statement but in Load statement you can select the ones you need. Also observe Year and Month Calculations. Preceding Load allows you to use QlikView functions like Year,Month,ApplyMap etc.
There can be multiple preceding loads stacked one on the top of other.
Preceding load can be a useful tool to simplify your data transformations.