Native xBase/FoxPro Access: Specific features and remarks

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Native xBase/FoxPro Access: Specific features and remarks

Overview

Main remarks

Specific features

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Native xBase/FoxPro Access: Specific features and remarks

Available only with this kind of connection

Overview

This help page presents the specific features regarding the programming of Native xBase/FoxPro Access.

The following image file formats are supported:

dBase3+
dBase4
FoxPro/FoxBase (up to version 9)
Clipper5
Clipper87

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

Main remarks

Managing the integrity and duplicates

The duplicates and the integrity are not supported.

Memo files

The memo files are automatically opened and managed with the data files.

Automatic data modification

The automatic modification of HFSQL data files cannot be used with the xBase/FoxPro files.

Locking the data files

Only the entire data file can be locked in write mode and/or in read-only. Indeed, locking some of the data file records is not allowed by the native xBase/FoxPro access.

Deleting records

A record can be deleted by HDelete or by HCross. On xBase/FoxPro files, HDelete and HCross have the same effect: The record is "crossed".

Number of records

HNbRec associated with the hStateActive or hStateAll constant also returns the number of crossed (or deleted) records, for backward compatibility with WINDEV 5.5.

However, you can find out the number of crossed or deleted records by using HNbRec with the hStateDel or hStateCrossed constant.

Finding records

During a search, if the number of characters in the sought value is greater than the maximum number of characters in the key item on which the search is performed, the search is performed on the N characters found in the sought value (where N is the maximum number of characters in the key item).

Example: The maximum number of characters in the key item named ITM of FILE is 3. The key item named ITM contains "abc" and "abd".

If the sought value contains more than 3 characters, only the first 3 characters of this value will be taken into account.

If the sought value is "abcd", the search will be performed on "abc" (one record will be found).
If the sought value is "abhd", the search will be performed on "abh" (no record will be found).

Remark: In the searches and filters, the blank dates (empty string) are greater than the other date values.

Dynamic description of data files

The description of an xBase file can be done in WLanguage (a project associated with a HFSQL or xBase analysis must be opened); you must use:

The created file is in dBase 3 format.

The file described in WLanguage can contain memo items and keys.

These commands can be used to create temporary files.

HFSQL files and xBase/FoxPro files

The same project can handle both HFSQL files and xBase/FoxPro files.

Caution: In the same project, a HFSQL data file and an xBase/FoxPro data file cannot have the same logical name, otherwise an error will occur.

Specific features

Analysis options

No matter whether the options ("Case sensitive", "Accent sensitive" and "Punctuation sensitive") are checked in the data model editor, the search will always be sensitive to the case, to the accented characters and to the punctuation.

Array items

The array items are not supported by the Native Access. If you are using an Array item, only the value of subscript 1 in the array will be handled by the HFSQL functions (in read/write).

Independent HFSQL context

The management of the independent HFSQL contexts (check box available in the description of windows or reports) is not available in this version.

Transactions

No transaction can be performed (HTransactionStart) on Native xBase/FoxPro Access.

Limits of xBase data files

See Files in xBase format: Limits to get the list of known limitations for xBase/FoxPro data files.

Multiple dBase4 indexes (MDX) and FoxPro indexes (CDX)

The Native xBase/FoxPro Access does not support the two following conditions used jointly:

Index based on an expression other than the single value of the item (for example UPPER(ITM1) or ITM1 + ITM2).
Name of the logical index identical to one of the items found in the xBase/FoxPro file.

The index file will not be recognized.

Solution: Rename the logical index.