Description
Finds a large value at a specified ranking in a column (for example, third- largest, fifth-largest) and returns the value of another column or expression based on the result.
Syntax
Large ( returnexp, column, ntop { FOR range { DISTINCT { expres1
{, expres2 {, ... } } } } } )
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Argument |
Description |
|---|---|
|
returnexp |
The value you want returned when the large value is found. Returnexp includes a reference to a column, but not necessarily the column that is being evaluated for the largest value, so that a value is returned from the same row that contains the large value. |
|
column |
The column that contains the large value you are searching for. 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. The datatype of column must be numeric. |
|
ntop |
The ranking of the large value in relation to the column's largest value. For example, when ntop is 2, Large finds the second-largest value. |
|
FOR range (optional) |
The data that will be included when the largest value is found. For most presentation styles, values for range are:
For Crosstabs, specify CROSSTAB for range:
For Graph and OLE objects, specify one of the following:
|
|
DISTINCT (optional) |
Causes Large to consider only the distinct values in column when determining the large 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 need to evaluate to determine distinct rows. Expresn can be the name of a column, a function, or an expression. |
Return value
The datatype of returnexp. Returns the ntop-largest value if it succeeds and -1 if an error occurs.
Usage
If you specify range, Large returns the value in returnexp when the value in column is the ntop-largest value in range. If you specify DISTINCT, Large returns returnexp when the value in column is the ntop-largest value of the distinct values in column, or if you specify expresn, the ntop-largest for each distinct value of expresn.
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 are as follows:
-
For the Graph or OLE presentation style, Rows is always All
-
For Graph controls, Rows can be All, Page, or Group
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For OLE controls, Rows can be All, Current Row, Page, or Group. The available choices depend on the layer the control occupies
Max might be faster
If you do not need a return value from another column and you want to find the largest value (ntop = 1), use Max; it is faster.
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
These expressions return the names of the salespersons with the three largest sales (sum_sales is the sum of the sales for each salesperson) in group 2, which might be the salesregion group. Note that sum_sales contains the values being compared, but Large returns a value in the name column:
Large(name, sum_sales, 1 for group 2) Large(name, sum_sales, 2 for group 2) Large(name, sum_sales, 3 for group 2)
This example reports the salesperson with the third-largest sales, considering only the first entry for each person:
Large(name, sum_sales, 3 for all DISTINCT sum_sales)
See also
