HStatNbRecRange (Function)

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Statistics on composite keys
Various

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HStatNbRecRange (Function)

In french: HStatNbEnrIntervalle

Available only with these kinds of connection

Returns an estimate regarding the number of entries for a given key item in a given interval of values. This estimate is deduced from the information obtained during the last statistical calculation.

Remark: From version 19, HFSQL is the new name of HyperFileSQL.

Example

// Calculate the statistics on the CustName key found in Customer data file
ResStat = HStatNbRecRange(Customer, CustName, "Clark", "Smith")

Syntax

<Result> = HStatNbRecRange([<Data file> [, <Key item>, ]] <Lower bound> , <Upper bound>)

<Result>: Integer

Number of entries found for the specified item in the requested interval.
Corresponds to the hInvalidRecNum constant if:
the statistics have never been calculated for the specified item.
the statistics are not supported by the specified type of item. HFSQL allows you to perform statistical calculations on key items only.

<Data file>: Optional character string (with or without quotes)

Name of data file used. If this name is not specified, HStatNbRecRange will use the last data file used by the last HFSQL management function (function starting with "H").

<Key item>: Optional character string (with or without quotes)

Name of key item used to perform the statistical calculation. If this name is not specified, HStatNbRecRange will use the last item used by the last HFSQL management function (function starting with "H").

<Lower bound>: Type of key item

Lower value of interval.

<Upper bound>: Type of key item

Upper value of interval.

Remarks

Statistics on composite keys

The following syntax allows you to calculate statistics on a composite key:

HStatNbRecRange(<Data file>, <Name of composite key>),
[<Lower bound of first element of composite key>,
<Lower bound of second element of composite key>],
[<Upper bound of first element of composite key>,
<Upper bound of second element of composite key>, ...])

Example:

HStatNbRecRange(Customer, LastName_FirstName, ["Black", "Alicia"], ["Morgan","Vince"])

Various

The statistics can be updated by HIndex and HStatCalculate.
In the HFSQL Classic data files, the statistical calculations can only be performed on key items.

Component : wd250hf.dll