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  • Filter
  • Filtered browse
  • Enabling/Disabling a filter
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Stored procedures
Defines and enables a "Contains" filter on a data file, view or query. The "Contains" filter is used to select all the records containing a specific set of characters.
This filter is not case sensitive.
This filter does not use any index, it browses the entire data file.
Example
SearchKey is string = HFilterContains(Customer, Comment, "VIP")
HReadFirst(Customer, SearchKey)
WHILE NOT HOut()
Trace(Customer.CustomerName, Customer.City)
HReadNext(Customer, SearchKey)
END
// Disables the filter
HDeactivateFilter(Customer)
Syntax
<Result> = HFilterContains(<Data file> , <Item> , <Value>)
<Result>: Character string
Browse item. Corresponds to:
  • the name of item used to loop through the data file if the filter is enabled,
  • an empty string ("") if the filter cannot be implemented.
<Data file>: Character string
Name of the HFSQL data file, view or query used.
<Item>: Character string
Name of item on which the filter will be implemented. This item can be a key item or a non-key item.
<Value>: Character string
Value that must be found in the record item.
Remarks

Filter

  • The filter is enabled as soon as HFilterContains is called.
  • Equivalent syntaxes:
    HFilterContains(FileName, ItemName, "Value")

    is equivalent to:
    HFilter(FileName, "ItemName ~]'Value'")

Filtered browse

When a filter is defined and enabled on a data file, any record read corresponds to the filter. If no other record corresponds to the filter during the iteration:
  • HOut 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:
HReadFirstthe first file record corresponding to the filter.
HReadLastthe last file record corresponding to the filter.
HReadNext (or HForward)the next record (or the next nth record) corresponding to the filter.
HReadPrevious (or HBackward)the previous record (or the previous nth record) corresponding to the filter.

Enabling/Disabling a filter

  • HDeactivateFilter is used to disable a filter.
  • HActivateFilter is used to re-enable a filter.
  • The filter is deleted when the data file (query or view) is closed (HClose or HOpenAnalysis for example).
  • A single filter can exist at a given time on a data file (query or view). If HFilterContains 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.
Component: wd290hf.dll
Minimum version required
  • Version 17
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Last update: 07/06/2023

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