Tuesday, December 2, 2008

Loading Variables Via Loadscript

You have two basic alternatives if you want to load document variables from a database or file. You can load them as part of the loadscript as you load data for reporting, or, you can load them through a macro script either within the QlikView document or external to the document.

In order to load variables from a database or file you must first have the variable names and the variable contents defined in the database table or in the file. The file might be a spreadsheet or text file but it must have one column or field defined for the variable names and a second column or field defined for the variable contents.

Within the QlikView loadscript you first load the variable names and contents into a QlikView table. From a database you might code it something like this:


Then insert some code like this to convert the table into document variables:

Let RowCount = NumMax(NoOfRows('RPT_VARS'),0)-1;
For i=0 to '$(RowCount)'
  Let TempVarName = peek('VAR_NAME',$(i),'RPT_VARS');
  Let TempVarValue = peek('VAR_VALUE',$(i),'RPT_VARS');
  Let $(TempVarName) = '$(TempVarValue)';

//If the table is no longer needed it can be dropped
Drop table RPT_VARS;

Note the NumMax function. That is necessary if the RPT_VARS table were ever empty; a null RowCount variable will cause a never-ending loop.

At work we have some reports where all of the expressions and titles and field labels are handled with variables. This allows us to use the same report at several different companies but the appearance and functionality of the report is tailored to local terminology and business practice. Another way to use this concept might allow the same report at a single company to look and work differently when it loads data from different databases that contain different sets of customized variables. So, a standard sales report could look different for the Commercial Division than it does at the Baked Goods Division.

1 comment:

Rob Wunderlich said...


Thanks for this interesting series on variables.

Another handy technique for loading variables from a file is using the include script statement.


Where RPT_VARS.csv contains:
SET var1=5;
SET company=ABC Corp;

Keep up the great posts!