Databases Reference
In-Depth Information
There is something we can do about this: simply add a calculated field to the
Employment
table before concatenating it to the
Main Data
table. In the end,
both table segments contain the
Quarter
field. If we do not add the
Quarter
field to the
Employment
table, any user selection on this field will automatically
exclude all of the employment data.
Natural and forced concatenation
Moving on to concatenating tables, as we saw in the previous chapter, there are
two ways in which this operation can take place in QlikView:
• Natural concatenation
• Forced concatenation
Let's take a moment to revisit this subject and see how we can apply it to our
fact tables.
Natural concatenation
Natural concatenation happens when two tables are loaded with exactly the same
structure, that is, they contain the exact same fields (in both the number of fields
and field names).
When this condition is met, QlikView automatically combines all tables that are
similar and treats them as one logical table.
An example of this is shown in the next script:
Sales:
Load
Region,
Month,
Year,
[Total Amount]
From Sales2011.qvd (qvd);
Load
Region,
[Total Amount],
Month,
Year
From Sales2010.qvd (qvd);
