- Characteristics of created data file
- Additional files created
- Managing passwords
- Managing fatal errors when creating a data file
- Managing non-Latin character sets
- Replication: Range of identifiers
- Priority for defining the location of log files
- Creating or opening an existing table
- Managing indexes
- Creating the data file from its description
HCreationIfNotFound (Function) In french: HCréationSiInexistant
 Not available with this kind of connection
Performs the following operations: - If the data file does not exist, creates an empty data file (".FIC" extension) with the index file and the memo file if necessary.
The function is equivalent to HCreation. - If the data file exists, opens the data file.
In this case, the function is equivalent to HOpen.
To optimize the call to HCreationIfNotFound, the file can be opened only when accessing the data file for the first time (using the hDelayedOpening constant).
Remark: The automatic creation of non-existing data files can be enabled in the project description ("Files" tab of the project description, "Automatically create the data files when they are opened"). HCreationIfNotFound is automatically used if the data file does not exist when it is handled for the first time.
// Create all the data files described in the analysis
// with the "PSW" password
HCreationIfNotFound("*", "PSW")
// Create the Orders data file (described in the analysis)
HCreationIfNotFound(Orders)
Syntax
<Result> = HCreationIfNotFound([<Data file> [, <Password> [, <Path of the JNL file> [, <Path of the JournalOperation file>]]] [, <Option>]])
<Result>: Boolean - True if the data file was created or opened,
- False if a problem occurs. HError is used to identify the error. If a fatal error occurs, a specific process is required to continue the program and to check whether the data file was created (see the Notes).
<Data file>: Optional character string Name of data file to use.
If this name is not specified, HCreationIfNotFound will use the last data file used by the last HFSQL function (function starting with "H").
If this parameter is equal to "*", all the data files found in the current analysis will be created or opened. If a password is specified, this password is used for all the data files.
This parameter can also correspond to the name of a group of files (or custom-folder) defined in the analysis (not available in Android and Android widget). If a password is specified, this password is used for all the data files of the group.
Caution: this parameter cannot be a variable of type File description.
<Password>: Optional character string - Password associated with the data file.
- Empty string ("") if no password is used.
<Path of the JNL file>: Optional character string Access path to the JNL file associated with the logged data file. This parameter is only taken into account if the data file is logged. In this case, <File name>JNL.fic will be created at the specified location.
<Path of the JournalOperation file>: Optional character string Access path to the JournalOperation file and to the JournalIdentification file associated with the logged data file. The JournalOperation file contains all the operations performed on the logged data file. This parameter is only taken into account if the data file is logged.
<Option>: Optional constant Optimize the opening of existing data files. | | | hChangeCharset | The character set defined by ChangeCharset will be taken into account in the new data file. Sorts, searches or other types of operations performed on string keys (strings, characters, date and time) will use the new character set. | | hDelayedOpening | If the data file already exists, it will be opened during the first access to the data file. If the data file does not exist, it is created and opened. | | hNoLink | Management of integrity: The links are not updated on the server (creation, modification or deletion).
Reminder: By default, the links are updated on the server when creating a data file.
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Remarks Managing passwords The password can be defined: - when the data file is created or opened by HCreationIfNotFound.
- before the data file is created by HPass.Caution: The password is independent of data encryption. The data encryption must be configured during the file description in the data model editor ("Details" tab).
Managing fatal errors when creating a data file If a fatal error occurs when creating a data file, it may be interesting to continue the program while checking whether the data file was created or not. To do so, we recommend that you perform the following exception process:
WHEN EXCEPTION IN
HCreationIfNotFound(PARENT)
DO
Error("HFSQL error: " + HError())
ELSE
Trace("The file is created")
END
Creating the data file from its description The data file can be directly created from its description in the data model editor. To do so, select "Create the data file" from the popup menu of the data file (in the analysis graph) and select the directory in which the data file must be created.
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