Databases Reference
In-Depth Information
Notice how the sheet tab says
Details for
, without including a carrier name. This
happens when there is more than one carrier selected. QlikView will only display
the name when a single carrier is selected. Let's make this right:
1.
Press
Ctrl
+
Alt
+
S
to open the
Sheet Properties
dialog.
2.
In the
Show Sheet
group, select the
Conditional
radio button.
3.
Enter the expression:
count(distinct [Carrier Name]) = 1
4.
Click on
OK
to close the
Sheet Properties
dialog.
If your selection contained more than one carrier, you will immediately notice that
the sheet disappears, as the expression counts the number of unique carrier names
that is selected. Only when you select a single carrier, or make a selection that is
associated with a single carrier, will the sheet be shown.
Show all sheets and objects
Ctrl
+
Shift
+
S
overrides all conditional show conditions,
immediately making all hidden sheets and objects visible.
This is a very useful key combination to remember during
development. Be very careful to undo this change before
moving your application into a production environment.
Besides conditionally showing objects and sheets, we can also add a
calculation
condition
to our charts. When a calculation condition is added to a chart, it
will only be calculated when the condition is met. Use cases for the calculation
condition include:
• Preventing the calculation of charts which have specified requirements with
regards to the current selection. For example, a chart that compares two
carriers should only be calculated when two carriers are selected.
• Preventing the calculation of charts which would need a great amount of
resources. For example, a straight table with hundreds of thousands of
rows. No one is going to read them all and they require a lot of resources to
be displayed.
