First DataWindow expression function

Description

Reports the value in the first row in the specified column.

Syntax

<span>First</span> ( <span>column</span> { FOR <span>range </span> { DISTINCT { <span>expresn </span> {, <span>expres2</span> {, ... } } } } } )

1	<span>First</span> ( <span>column</span> { FOR <span>range </span> { DISTINCT { <span>expresn </span> {, <span>expres2</span> {, ... } } } } } )

Argument	Description
column	The column for which you want the value of the first row. Column can be a column name or a column number preceded by a pound sign (#). Column can also be an expression that includes a reference to the column.
FOR range (optional)	The data that will be included when the value in the first row is found. Values for range depend on the presentation style. See the Usage section for more information.
DISTINCT (optional)	Causes First to consider only the distinct values in column when determining the first value. For a value of column, the first row found with the value is used and other rows that have the same value are ignored.
expresn (optional)	One or more expressions that you want to evaluate to determine distinct rows. Expresn can be the name of a column, a function, or an expression.

Return Values

The datatype of the column. Returns the value in the first
row of column. If you specify range, First returns
the value of the first row in column in range.

Usage

If you specify range, First determines
the value of the first row in column in range.
If you specify DISTINCT, First returns the first
distinct value in column, or if you specify expresn,
the first distinct value in column where the
value of expresn is distinct.

For most presentation styles, values for range are:

ALL – (Default)
The value in the first of all rows in column.
GROUP n – The value
in the first of rows in column in the specified
group. Specify the keyword GROUP followed by the group number: for
example, GROUP 1.
PAGE – The value in the first of the rows
in column on a page.

For Crosstabs, specify CROSSTAB for range to
indicate the first of all rows in column in
the crosstab.

For Graphs specify GRAPH and for OLE objects specify OBJECT
for range, to indicate the value in the first
row in column in the range specified for the Rows
option.

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.

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 first value in column
3 on the page:

<span>First</span>(#3 for page)

1	<span>First</span>(#3 for page)

This expression returns the first distinct value
in the column named dept_id in group 2:

<span>First</span>(dept_id for group 2 DISTINCT)

1	<span>First</span>(dept_id for group 2 DISTINCT)

This expression returns the first value in the column
named dept_id in group 2:

<span>First</span>(dept_id for group 2)

1	<span>First</span>(dept_id for group 2)

First – PB Docs 150