Count
DataWindow expression function
Description
Calculates the total number of rows in the specified column.
Syntax
|
1 |
Count ( column { FOR range { DISTINCT { expres1 {, expres2 {, ... } } } } } ) |
|
Argument |
Description |
|---|---|
|
column |
The column for which you want the number of rows. |
|
FOR range (optional) |
The data that will be included in the count. For most
For Crosstabs, specify CROSSTAB for
For Graph and OLE objects, specify one of
|
|
DISTINCT (optional) |
Causes Count to consider only the distinct values in |
|
expresn (optional) |
One or more expressions that you want to evaluate to |
Usage
If you specify range, Count determines the number of rows in
column in range. If you specify DISTINCT, Count returns the number of the
distinct rows displayed in column, or if you specify expresn, the number
of rows displayed in column where the value of expresn is distinct.
For graphs and OLE objects, you do not select the range when you
call the function. The range has already been determined by the Rows
setting on the Data property page (the Range property), and the
aggregation function uses that range.
Settings for Rows include the following:
-
For the Graph or OLE presentation style, Rows is always
All. -
For Graph controls, Rows can be All, Page, or Group.
-
For OLE controls, Rows can be All, Current Row, Page, or Group.
The available choices depend on the layer the control occupies.
Null values in the column are ignored and are not included in the
count.
Not in validation rules or filter expressions
You cannot use this or other aggregate functions in validation
rules or filter expressions.
Using an aggregate function cancels the effect of setting Retrieve
Rows As Needed in the painter. To do the aggregation, a DataWindow
object always retrieves all rows.
Examples
This expression returns the number of rows in the column named
emp_id that are not null:
|
1 |
Count(emp_id) |
This expression returns the number of rows in the column named
emp_id of group 1 that are not null:
|
1 |
Count(emp_id for group 1) |
This expression returns the number of dept_ids that are
distinct:
|
1 |
Count(dept_id for all DISTINCT) |
This expression returns the number of regions with distinct
products:
|
1 |
Count(region_id for all DISTINCT Lower(product_id)) |
This expression returns the number of rows in column 3 on the page
that are not null:
|
1 |
Count(#3 for page) |
See also