<Source>.FilterIdentical (Function)

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Automatic management of composite keys

Filter and filtered browse

Enabling/Disabling a filter

Data file not in HFSQL format

See also

<Source>.FilterIdentical (Function)

In french: <Source>.FiltreIdentique

Not available with this kind of connection

Defines and enables a filter used to find the exact value of a string item. This filter can be used on a data file, a view or a query.

After its execution, the most common cases are as follows:

the filter cannot be created: <Source>.FilterIdentical returns an empty string (""). HError returns the error identifier.
the filter is created: <Source>.FilterIdentical returns the optimized search key that will be used to browse the data file, view or query.

Versions 15 and later

This function is now available for Android applications.

New in version 15

This function is now available for Android applications.

Versions 17 and later

This function is now available for iPhone/iPad applications.

New in version 17

This function is now available for iPhone/iPad applications.

Versions 18 and later

This function is now available in Android Widget mode.

This function is now available in Windows Store apps mode.

New in version 18

This function is now available in Android Widget mode.

This function is now available in Windows Store apps mode.

This function is now available in Android Widget mode.

This function is now available in Windows Store apps mode.

Versions 21 and later

This function is now available in Universal Windows 10 App mode.

New in version 21

This function is now available in Universal Windows 10 App mode.

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

Example

// Select all the customers whose last name is Archambault
// and whose first name is Colin
SearchKey is string
SearchKey = Customer.FilterIdentical(LastNameFirstName, "Archambault", "Colin")
Customer.ReadFirst(SearchKey)
WHILE NOT Customer.Out()
Trace(Customer.CustomerName, Customer.City)
Customer.ReadNext(SearchKey)
END
// Disables the filter
Customer.DeactivateFilter()

Syntax

<Result> = <Source>.FilterIdentical(<Key item> , <Value for key component 1> [, <Value for key component 2> [... [, <Value for key component N>]]])

<Result>: Character string

Browse item. Corresponds to:
the search key of data file if the filter is enabled.
an empty string ("") if the filter cannot be implemented.

<Source>: Type corresponding to the specified source

Name of HFSQL data file, view or query used.

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

Name of key item onto which the filter will be applied. This item can be a simple key (string) or a composite key. Caution: this parameter must only contain letters, underlined characters or digits. Otherwise, the name must be enclosed in quotes.

<Value for key component 1>: Type of each component of search key

Value sought for the first component of composite key.
The type of this parameter must correspond to the type of key item component on which the filter is defined.

<Value for key component 2>: Type of each component of search key

Value sought for the second component of the composite key.
The type of this parameter must correspond to the type of key item component on which the filter is defined.

<Value for key component N>: Type of each component of search key

Value sought for component N of composite key .
The type of this parameter must correspond to the type of key item component on which the filter is defined.

Remarks

Automatic management of composite keys

<Source>.FilterIdentical automatically manages the filters on the simple keys and on the composite keys.

Example: Using <Source>.FilterIdentical with a simple key:

Res = Customer.FilterIdentical(LastName, "Archambault")
// Select the customer whose last name is Archambault

Example: Using <Source>.FilterIdentical with a composite key

Res = Customer.FilterIdentical(LastNameFirstName, "Archambault", "Colin")
// Select all the customers whose last name is Archambault and
// whose first name is Colin

This line of code is equivalent to:

Customer.Filter(LastNameFirstName, ...
Customer.BuildKeyValue(LastNameFirstName, "Archambault", "Colin"), ...
Customer.BuildKeyValue(LastNameFirstName, "Archambault", "Colin")

Filter and filtered browse

After the call to <Source>.FilterIdentical, the data file must necessarily be browsed on the item returned by <Source>.FilterIdentical. The filter will be ignored if another item is used to browse the data file.

When a filter is defined and enabled on a data file (view or query), all records read correspond to the filter. If no other record corresponds to the filter during the browse:

<Source>.Out returns True.
the current record corresponds to the last record read with the filter.

For example:

On a filtered data file, after the function:	the current record is:

<Source>.ReadFirst	the first file record corresponding to the filter.
<Source>.ReadLast	the last file record corresponding to the filter.
<Source>.ReadNext (or <Source>.Forward)	the next record (or the next nth record) corresponding to the filter.
<Source>.ReadPrevious (or <Source>.Backward)	the previous record (or the previous nth record) corresponding to the filter.

Enabling/Disabling a filter

<Source>.DeactivateFilter is used to disable a filter.
<Source>.ActivateFilter is used to re-enable a filter.
The filter is deleted when the data file (query or view) is closed (<Source>.Close or HOpenAnalysis for example).
A single filter can exist at a given time on a data file (query or view). If <Source>.FilterIdentical is used several times, only the last filter will be taken into account: the previous filters will be deleted. Similarly, if several filters are used (HFilter* functions), only the last filter will be taken into account.

Data file not in HFSQL format

The filter can be created from any item (key or non-key item).
The filter is automatically enabled when <Source>.FilterIdentical is run.
The modifications performed by <Source>.FilterIdentical and <Source>.DeactivateFilter are taken into account when using <Source>.ReadFirst/<Source>.First, <Source>.ReadLast/<Source>.Last or <Source>.ReadSeekFirst/<Source>.ReadSeekLast.

Component : wd250hf.dll