HDeclareExternal (Function)

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Function HDeclareExternal: Use with Native Connectors and/or the OLE DB Provider

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HDeclareExternal (Function)

In french: HDéclareExterne

Not available with this kind of connection

Temporarily imports into the current analysis the description of a data file from an existing HFSQL data file. This data file is opened. To no longer use this File Description, call HCancelDeclaration.

Example

See additional examples

// Déclaration d'un fichier de données FournisseurWD à partir du chemin complet 
// du fichier HFSQL Classic (extension .FIC comprise)
HDeclareExternal("C:\GestCom\Fournisseur.fic", "FournisseurWD")
IF ErrorOccurred = True THEN
	// Erreur de déclaration du fichier, on affiche l'erreur
	Error(HErrorInfo())
END

Syntax

Use with Classic HFSQL files (single-user or multi-user) Hide the details

<Result> = HDeclareExternal(<Full path of the HFSQL file> , <Alias> [, <Password>])

<Result>: Boolean

True if the operation was performed,
False if a problem occurs. HErrorInfo is used to identify the error.

<Full path of the HFSQL file>: Character string

Full access path to HFSQL data file whose description will be imported (up to 260 characters). This name must contain the path and extension of the data file.
If HDeclareExternal is used in a stored procedure, the file path must be relative to the current database.

<Alias>: Character string

Logical name of the data file. This name will be used to handle the data file. This name can also correspond to a Data Source variable.

<Password>: Optional character string

Password associated with the data file.
Empty string ("") if no password is used.
If the password is specified, it is retained: it is not necessary to specify this password again in future data file manipulation functions..

Use with an OLE DB access, a Native Connector, HFSQL Client/Server and an existing connection Hide the details

<Result> = HDeclareExternal(<Data file> , <Alias> , <Connection>)

<Result>: Boolean

True if the operation was performed,
False if a problem occurs. HErrorInfo is used to identify the error.

<Data file>: Character string

Name of the data file in the external database.
This parameter corresponds to the physical name of data file, in relation to the database (extension included). Example: "monfichier.fic" (or if the database has sub-directories: ".\repertoire\monfichier.fic").
If the data file is password protected, this password must be specified with HPass before using HDeclareExternal.

<Alias>: Character string

Logical name of the data file. This name will be used to handle the data file in the current application. This name can also correspond to a Data Source variable.

<Connection>: Character string

Connection to a database. This connection has been defined in the data model editor or described programmatically with HDescribeConnection.

Use with an OLE DB access or a Native Connector Hide the details

<Result> = HDeclareExternal(<Data file> , <Alias> , <User> [, <Password> [, <Data source> [, <OLE DB provider or Native Connector> [, <Access>]]]])

<Result>: Boolean

True if the operation was performed,
False if a problem occurs. HErrorInfo is used to identify the error.

<Data file>: Character string

Name of the data file in the external database.

<Alias>: Character string

Logical name of the data file. This name will be used to handle the data file in the current application.

<User>: Character string

Name of the user of the data source.

<Password>: Optional character string

Password of the data file to open (if there is a password).

<Data source>: Optional character string

Full path of the data source.

<OLE DB provider or Native Connector>: Optional character string

Name of the OLE DB provider or one of the following constants:
hNativeAccessAS400 Native AS/400 Connector (optional module)
hNativeAccessDB2 Native DB2 Connector (optional module)
hNativeAccessInformix Native Informix Connector (optional module)
hNativeAccessMariaDB Native MariaDB Connector (optional module of WINDEV/WEBDEV)
hNativeAccessMySQL Native MySQL Connector (optional module)
hNativeAccessOracle Native Oracle Connector (optional module)
hNativeAccessPostgreSQL Native PostgreSQL Connector (optional module of WINDEV/WEBDEV)
hNativeAccessProgress Native Progress Connector (optional module)
hNativeAccessSQLAzure Native SQL Azure Connector (optional module, supplied with Native SQL Server Connector)
hNativeAccessSQLite Native SQLite Connector
hNativeAccessSQLServer Native SQL Server Connector (optional module)
hNativeAccessSybase Native SYBASE Connector (optional module)
hNativeAccessXBase Native xBase Connector
hNativeAccessXML Native XML Connector
hODBC OLE DB provider for ODBC. Allows you to access an ODBC source declared in the ODBC data sources of Windows
hOledbAccess97 OLE DB provider for Access 97
hOledbAccess2000 OLE DB provider for Access 2000
hOledbAccess2007 OLE DB provider for Access 2007
hOledbAccess2010 OLE DB provider for Access 2010
hOledbDBase5 OLE DB provider for dBase 5
hOledbExcel2000 OLE DB provider for Excel 2000
hOledbExcel2007 OLE DB provider for Excel 2007
hOledbExcel97 OLE DB provider for Excel 97
hOledbLotus4 OLE DB provider for Lotus 4
hOledbOracle OLE DB provider for Oracle
hOledbSQLServer OLE DB provider for SQL Server
Caution: To use an OLE DB connection, you must:
install MDAC version 2.6 or later (setup performed by WINDEV/WEBDEV and when creating the client version)
install the OLE DB provider corresponding to the database used.

<Access>: Optional constant

Configures the type of access to the data file.
hORead The data file can be accessed in read-only. You can only read records. No record can be added or deleted.
hOReadWrite
(default value) The data file can be accessed in read/write. You can read and write new records.

Remarks

All the HFSQL functions can be used on the imported data file except for the integrity management.
You can import as many descriptions as necessary.
This function can be used with data files in XML format.
To use HDeclareExternal in a stored procedure:
- the relative path of the data file must be specified in relation to the directory of the database containing the stored procedure. The path must include the name and extension of the data file.
- don't use a connection: the current database containing the stored procedure will be used.
By default, if the current project:
- is associated with an analysis, the lock mode applied to the data files is the multi-user mode (the files are not locked when they are opened and they can be accessed by the other applications).
- is not associated with an analysis, the blocking mode applied to data files is single-user: files are completely blocked from reading and writing as soon as they are opened.. This mode prevents the other applications from accessing the files already opened by the current application.

Function HDeclareExternal: Use with Native Connectors and/or the OLE DB Provider

By default, the logical name passed to HDeclareExternal is considered as the only name in the table. It is encapsulated by using the encapsulation characters corresponding to the database or specified by the OLE DB provider before being sent to the database (this is used to manage the table names containing special characters).

To specify a file name composed of <Username>.<Table name> (or depending on the database, <Schema name>.<Table name>) in HDeclareExternal, these names must be already formatted (using encapsulation characters corresponding to the database, or specified by the OLE DB provider).

Example for SQLServer:
The encapsulation characters are " ".
To rename CUSTOMER as DBO.CUSTOMER using HDeclareExternal, you must pass "DBO"."CUSTOMER".
Therefore, the following code must be used:

HDeclareExternal("""DBO"".""CLIENT""", sdClient, "MaConnexion")

Component: wd300hf.dll