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  • Properties specific to the description of data files
  • How to describe the data files through programming?
  • Handling the items of a data file described through programming
  • LogMethod
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Stored procedures
File Description (Type of variable)
In french: Description de Fichier (Type de variable)
HFSQLHFSQL Client/ServerAvailable only with these kinds of connection
A File Description variable is used to describe one or more data files through programming. The description of each data file is validated by HDescribeFile.
After this validation:
  • This data file can be handled like any other data file described in the analysis.
  • The "File Description" variable is reinitialized and it can be used to describe another data file through programming.
Versions 17 and later
iPhone/iPad This type of variable is now available for iPhone and iPad applications.
New in version 17
iPhone/iPad This type of variable is now available for iPhone and iPad applications.
iPhone/iPad This type of variable is now available for iPhone and iPad applications.
Versions 18 and later
Universal Windows 10 App This type of variable is now available in Windows Store apps mode.
New in version 18
Universal Windows 10 App This type of variable is now available in Windows Store apps mode.
Universal Windows 10 App This type of variable is now available in Windows Store apps mode.
Versions 21 and later
Universal Windows 10 App This type of variable is now available in Universal Windows 10 App mode.
New in version 21
Universal Windows 10 App This type of variable is now available in Universal Windows 10 App mode.
Universal Windows 10 App This type of variable is now available in Universal Windows 10 App mode.
Remark: From version 19, HFSQL is the new name of HyperFileSQL.
Example
AFile is File Description
MyFile1, MyFile2 are File Descriptions
// Describe the "CUSTOMER" data file
AFile is File Description
 
AFile.Name = "CUSTOMER"
AFile.Type = hFileNormal
AFile.FicCryptMethod = hCryptStandard
 
// Description of the data file items
...
 
// Validate the description of "CUSTOMER"
HDescribeFile(AFile)
Syntax

Declaring one or more descriptions of data files Hide the details

<Variable name> is File Description
<Variable name 1>, <Variable name 2> are File Descriptions
<Variable name>:
Name of the "File Description" variable to declare.
Remark: The a and an keywords are optional: they provide better readability.

Describing a "File Description" variable Hide the details

To describe a "File Description" variable:
Use the WLanguage properties specific to the descriptions of data files. For more details, see remarks.
To validate the description of a "File Description" variable:
Remarks

Properties specific to the description of data files

The table below presents the properties specific to the description of data files:
Remark: The properties in bold followed by a star (*) must necessarily be initialized when a data file is described through programming.
Property nameEffect
MmoPackMethodCompression mode of the MMO file (containing the text and binary memos) associated with the data file
FicCryptMethodEncryption mode of the data file
MmoCryptMethodEncryption mode of memo file (.MMO extension) associated with the data file
NdxCryptMethodEncryption mode of index file associated with the data file
CtAccessType of access to the file during the OLE DB connection to a specific table (while taking into account the modifications performed by HConnect)
CtDescribedAccessType of access to the file during the OLE DB connection to a specific table (while ignoring the modifications performed by HConnect)
CtDatabaseOLE DB data source when connecting to a specific table (taking into account the changes made with HConnect)
CtDescribedDatabaseOLE DB data source when connecting to a specific table (ignoring the changes made with HConnect)
CtDescribedCaptionCaption of the connection to the OLE DB data source
CtDescribedPasswordPassword used to open the file during an OLE DB connection
CtOLEDBProviderName of the OLE DB server used (taking into account the changes made with HConnect).
CtDescribedOLEDBProviderName of the OLE DB server (ignoring the changes made with HConnect).
CtUserNameName of the user during an OLE DB connection (taking into account the changes made by HConnect).
CtDescribedUserNameName of the user during an OLE DB connection (ignoring the changes made with HConnect).
FormatFormat of data in the data file (ANSI or Unicode).
HugeFileMaximum size of a data file.
Versions 23 and later
Unalterable
New in version 23
Unalterable
Unalterable
Mode for managing the unalterability of data file.
LogMethodLog mode of a data file.
WDD55PasswordPassword that will be used to handle a file defined through programming in Hyper File 5.5 format in an analysis in WINDEV format.
Name ( * )Name of HFSQL file.
Name55Logical name of a file in Hyper File 5.5 format found in an analysis in WINDEV format.
DescribedNameLogical name of a data file.
PhysicalNamePhysical name of data files.
DescribedPhysicalNamePhysical name of HFSQL files (while ignoring the changes of name performed by HChangeName).
NullSupportedManagement mode of NULL value.
Versions 19 and later
RepeatableReadSupported
New in version 19
RepeatableReadSupported
RepeatableReadSupported
The file is used in an HFSQL Client/Server transaction that includes a "Repeatable Read" isolation mode.
DirectoryPhysical directory of HFSQL files (this property takes into account the changes of directory performed by HChangeDir or HSubstDir).
DescribedDirectoryPhysical directory of HFSQL files (this property ignores the changes of directory performed by HChangeDir or HSubstDir).
LogDirectoryDirectory of log file described in the analysis.
TextItemCompletedFills (or not) the text items with space characters.
SecureSecurity level regarding the encryption of data files.
TypeType of data file.
WDD55Path of the WDD file in 5.5 format used to handle the data files in 5.5 format in a WINDEV application.

How to describe the data files through programming?

To describe the data files through programming, you must:
  1. Declare the "File Description", "Item Description", "FullTextIndex description" and "Link description" variables (if necessary).
  2. For each data file:
  3. If necessary, describe the characteristics of the links using HFSQL properties.
  4. If necessary, validate the description of each link (HDescribeLink).

Handling the items of a data file described through programming

When creating a data file in the data model editor, the names of the data files and items are automatically recognized by the compiler.
When creating a data file using a "File Description" variable, the names of the data file and its items can be defined with the Name property. These names are not automatically recognized by the compiler. A compilation error occurs if these names are used to identify the data file or the items.
The name of the data file must be declared as data source using the data source keyword, for the compiler to recognize this name. This data file can be handled by its name in the code editor.
For example:
AFile is File Description
...
AFile.Name = "CUSTOMER"
...
HDescribeFile("CUSTOMER")
...
CUSTOMER is Data Source
...
HReadFirst(CUSTOMER, "CUSTNAME")
Remark: The name of the data file can also be declared with the Extern keyword. However, the process execution will be slower.

LogMethod

When the data file is described through programming:
  • if the data file is logged and if no item is logged, all the items (except for the composite keys) are automatically logged.
  • if the data file is logged and if at least one item is logged, the other items are not modified.
Minimum version required
  • Version 9
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