Associating data with a crosstab
You associate crosstab columns, rows, and cell values with
columns in a database table or other data source.
To associate data with a crosstab:
-
If you are defining a new crosstab, the
Define Crosstab Rows, Columns, Values dialog box displays after
you specify the data source.
-
Specify the database columns that will populate
the columns, rows, and values in the crosstab, as described below. -
To build a dynamic crosstab, make sure theRebuild
Columns At Runtime box is selected.For information about static crosstabs, see “Creating static crosstabs”.
-
Click Next.
Specifying the information
To define the crosstab, drag the column names from the Source
Data box in the Crosstab Definition dialog box (or Wizard page)
into the Columns, Rows, or Values box, as appropriate.
If you change your mind or want to edit the DataWindow object later,
select Design>Crosstab from the menu bar and drag the column
name out of the Columns, Row, or Values box and drop it. Then specify
a different column.
Dynamic crosstab example
The process is illustrated using the following dynamic crosstab.
The columns in the database are Rep, Quarter, Product, and Units.
The crosstab shows the number of printers sold by Quarter:
Specifying the columns
You use the Columns box to specify one or more of the retrieved
columns to provide the columns in the crosstab. When users run
the crosstab, there is one column in the crosstab for each unique
value of the database column(s) you specify here.
To specify the crosstab’s columns:
-
Drag the database column from the Source
Data box into the Columns box.
Using the printer example, to create a crosstab where the
quarters form the columns, specify Quarter as the Columns value.
Because there are four values in the table for Quarter (Q1, Q2,
Q3, and Q4), there are four columns in the crosstab.
Specifying the rows
You use the Rows box to specify one or more of the retrieved
columns to provide the rows in the crosstab. When users run
the crosstab, there is one row in the crosstab for each unique value
of the database column(s) you specify here.
To specify the crosstab’s rows:
-
Drag the database column from the Source
Data box into the Rows box.
Using the printer example, to create a crosstab where the
printers form the rows, specify Product as the Rows value. Because
there are three products (Cosmic, Galactic, and Stellar), at runtime
there are three rows in the crosstab.
Columns that use code tables If you specify columns in the database that use code tables,
where data is stored with a data value but displayed with more meaningful
display values, the crosstab uses the column’s display
values, not the data values. For more information about code tables,
see Chapter 22, “Displaying and Validating
Data .”
Specifying the values
Each cell in a crosstab holds a value. You specify that value
in the Values box. Typically you specify an aggregate function,
such as Sum or Avg, to summarize the
data. At runtime, each cell has a calculated value based on the
function you provide here and the column and row values for the
particular cell.
To specify the crosstab’s values:
-
Drag the database column from the Source
Data box into the Values box.PowerBuilder displays an aggregate function for the value. If
the column is numeric, PowerBuilder uses Sum. If
the column is not numeric, PowerBuilder uses Count. -
If you want to use an aggregate function other
than the one suggested by PowerBuilder, double-click the item in the
Values box and edit the expression. You can use any of the other
aggregate functions supported in the DataWindow painter, such as Max, Min,
and Avg.
Using the printer example, you would drag the Units column
into the Values box and accept the expression sum(units
for crosstab).
Using expressions
Instead of simply specifying database columns, you can use
any valid DataWindow expression to define the columns, rows, and values used
in the crosstab. You can use any non-object-level DataWindow expression function in
the expression.
For example, say a table contains a date column
named SaleDate, and you want a column in the
crosstab for each month. You could enter the following expression
for the Columns definition:
|
1 |
Month(SaleDate) |
The Month function returns the integer
value (1–12) for the specified month. Using this expression,
you get columns labeled 1 through 12 in the crosstab. Each database
row for January sales is evaluated in the column under 1, each database
row for February sales is evaluated in the column under 2, and so
on.
To specify an expression for columns, rows, or
values:
-
In the Crosstab Definition dialog box (or
wizard page), double-click the item in the Columns, Rows, or Values
box.The Modify Expression dialog box displays.
-
Specify the expression and click OK.
Viewing the crosstab
After you have specified the data for the crosstab’s
columns, rows, and values, PowerBuilder displays the crosstab definition
in the Design view.
For example, to create the dynamic crosstab shown as the “Dynamic crosstab example”, you would:
- Drag the quarter column
from the Source Data box to the Columns box. - Drag the product column from
the Source Data box to the Rows box. - Drag the units column from
the Source Data box to the Values box and accept the expression sum(units
for crosstab). - Select the Rebuild Columns at Runtime check box
.
In the Design view, the crosstab looks like this:
Notice that in the Design view, PowerBuilder shows the quarter entries
using the symbolic notation @quarter (with
dynamic crosstabs, the actual data values are not known at definition
time). @quarter is
resolved into the actual data values (in this case, Q1, Q2, Q3,
and Q4) when the crosstab runs.
The crosstab is generated with summary statistics: the rows
and columns are totaled for you.
At this point, the crosstab looks like this in the Preview
view with data retrieved:
- Because quarter was
selected as the Columns definition, there is one column in the crosstab
for each unique quarter (Q1, Q2, Q3, and Q4). - Because product was selected
as the Rows definition, there is one row in the crosstab for each
unique product (Cosmic, Galactic, and Stellar). - Because sum(units for crosstab) was
selected as the Values definition, each cell contains the total
unit sales for the corresponding quarter (the Columns definition)
and product (the Rows definition). - PowerBuilder displays the grand totals for each column
and row in the crosstab.
Specifying more than one row or column
Typically you specify one database column as the Columns definition
and one database column for the Rows definition, as in the printer
crosstab. But you can specify as many columns (or expressions) as
you want.
For example, consider a crosstab that has the same specification
as the crosstab in “Viewing the crosstab”, except that two database columns, quarter and rep,
have been dragged to the Columns box.
PowerBuilder displays this in the Design view:
This is what you see at runtime:
For each quarter, the crosstab shows sales of each printer
by each sales representative.