MORE INFORMATION
Overview of the Microsoft OLE DB Provider for AS/400 and VSAM
To use Microsoft OLE DB Provider for AS/400 and VSAM with an OLE DB consumer application, you must either:
- Create a Microsoft data link file (.UDL) and call this from your application.
-or-
- Call the provider using a connection string that includes the provider name.
Microsoft Data Access Components (MDAC) 2.0 and later include Data Links, a generic method for managing and loading connections to OLE DB data sources. Data Links also support finding and persisting connections to OLE DB data sources.
If you are accessing VSAM data sets, then after configuring a Data Link, you must configure host data descriptions using the SNA Data Descriptions Utility. See the online Help accessible through the utility for additional information on configuring data descriptions and creating host column description (HCD) files. For additional information on using UDLs, as well as a list of supported OLE DB initialization properties and ADO connection string arguments, see "Using the OLE DB Provider for AS/400 and VSAM" in the SNA Server SDK online documentation or the SNA Data Descriptions Utility online Help under the topic: "Configuring a data source for OLE DB Provider for AS/400 and VSAM."
OLE DB Data Links
You must configure data source information for each AS/400 or mainframe system data source object that is to be accessed using OLE DB Provider for AS/400 and VSAM. The default parameters for OLE DB Provider for AS/400 and VSAM are used only when these parameters are not configured for each data source.
Microsoft Data Links provides a uniform method for creating file-persistent OLE DB data source object definitions in the form of Universal Data Link (UDL) files. Applications, such as the RowsetViewer sample included with the SNA Server SDK, can open created UDL files and pass the stored initialization string to OLE DB Provider for AS/400 and VSAM at run time.
Adding or Configuring a Data Link
You must create a Data Link to configure parameters for your OLE DB data source. You can create a new Data Link by clicking the shortcut in the SNA Server program folder. The properties of a Data Links file can be edited by opening the file from Windows Explorer. To edit the Data Links file:
For Windows NT
- From the Start menu, select the Microsoft SNA Server program group.
- Select the Data Access program group.
- Select New OLE DB Data Source. The Data Link Properties page appears.
- Configure the data source information for the selected provider. Click Help for more information.
- Click OK to save the Data Link.
For Windows 95/98
- From the Start menu, select the Microsoft SNA Server program group.
- Select the Data Access program group.
- Select New OLE DB Data Source. The Data Link Properties page appears.
- Configure the data source information for the selected provider. Click Help for more information.
- Click OK to save the Data Link.
By default, Data Links are created in the Program Files\Common Files\System\OLE DB\Data Links folder. However, you can create a Data Link in any location by opening the target folder, selecting
New Microsoft Data Link from the
File menu, and configuring the
Data Link Properties page.
Browsing OLE DB Data Sources
By default, Data Links are created in the Program Files\Common Files\System\OLE DB\Data Links folder. A shortcut is provided in the Microsoft SNA Server program group. To browse the data sources:
- From the Start menu, select the Microsoft SNA Server program group.
- Select the Data Access program group.
- Select Browse OLE DB Data Source. The list of Data Links saved in the default location is displayed.
Configuring Data Links
The
Provider tab allows you to select the OLE DB provider (the provider name string) to be used in this UDL file from a list of possible OLE DB providers. Choose
Microsoft OLE DB Provider for AS/400 and VSAM.
The
Connection tab allows you to configure the basic properties required to connect to a data source. For OLE DB Provider for AS/400 and VSAM, the connection properties include the following values:
Data Source: The data source is an optional parameter that can be used to describe the data source. When the Data Links configuration program is loaded from the SNA Server program folder, the Data Source field is required. This field is used to name the UDL file, which is stored in the Program Files\Common Files\System\OLE DB\Data directory.
Location: The remote database name required for connecting to OS/400 systems. This parameter is not used when connecting to a mainframe system. In OS/400, this property is referred to as RDBNAM. The RDBNAM value can be determined by invoking the WRKRDBDIRE command from the console to the OS/400 system. If there is no RDBNAM value, then one can be created using the Add option.
User name: A valid user name is normally required to access data sources on a host computer.
Password: A valid password is normally required to access data sources on a host computer. Optionally, you can choose to save the password in the UDL file by selecting the Allow saving password check box.
WARNING: This option persists the authentication information in plain text within the UDL file.
The
Connection tab also includes a
Test Connection button that can be used to test the connection parameters. The connection can only be tested after all of the required parameters are entered. When you click this button, a session is established to the host computer using OLE DB Provider for AS/400 and VSAM.
The
Advanced tab exposes OLE DB standard properties. For OLE DB Provider for AS/400 and VSAM, the advanced properties include the following values:
Access permissions: The mode property is used to set the access permissions on the data source object. As implemented by the OLE DB Provider for AS/400 and VSAM, the mode applies to host file locks; it does not apply to record locks. The default mode for the OLE DB Provider for AS/400 and VSAM is ReadWrite.
Connection Timeout: The amount of time (in seconds) to wait for initialization to complete. This parameter is not currently supported by the OLE DB Provider and defaults to 0.
Impersonation Level: The level of impersonation that the server is allowed to use when impersonating the client. The provider default value is Impersonate.
Protection Level: The OLE DB Provider for AS/400 and VSAM does not support this value.
The
All tab allows you to configure additional properties used to connect to a data source. Some of the properties in the
All tab are required. These properties can be edited by selecting a property from the displayed list, and clicking
Edit Value. For Microsoft OLE DB Provider for AS/400 and VSAM, these properties include the following values:
APPC Local LU Alias: The name of the local LU alias configured in the SNA server.
APPC Mode Name:The APPC mode that must be set to a value that matches the host configuration and SNA server configuration. Legal values for the APPC mode include QPCSUPP (common system default), #INTER (interactive), #INTERSC (interactive with minimal routing security), #BATCH (batch), #BATCHSC (batch with minimal routing security), and custom modes. The following modes that support bi-directional LZ89 compression are also legal: #INTERC (interactive), INTERCS (interactive), BATCHC (batch), and BATCHCS (batch).
APPC Remote LU Alias: The name of the remote LU alias configured in the SNA server.
Cache Authentication: The provider's data source object or enumerator is allowed to cache sensitive authentication information such as a password in an internal cache. The default for this property is False.
Default Library: The default AS/400 library to be accessed. This parameter is not required for mainframe access and is optional when connecting to AS/400 files.
Encrypt Password: The OLE DB Provider for AS/400 and VSAM does not support this value.
Extended Properties: A method to specify additional provider-specific properties. Properties passed using this parameter should be delimited by semicolons and will be interpreted by the provider's underlying network client.
Host CCSID: The character code set identifier (CCSID) matching the data as represented on the host computer. This parameter defaults to U.S./Canada (37). The CCSID property is required when processing binary data as character data. Unless the Process Binary as Character value is set, character data is converted based on the host column CCSID and default ANSI code page.
Host Column Description File: The fully qualified file name of the DDM host column description (HCD) file, for example: C:\Program Files\SNA\System\Sample.hcd. This parameter can be a UNC string up to 256 characters. This property is required when connecting to a mainframe system and is optional when connecting to OS/400.
Impersonation Level: The level of impersonation that the server is allowed to use when impersonating the client. The provider default value is Impersonate.
Integrated Security: The OLE DB Provider for AS/400 and VSAM does not support this value.
Locale Identifier: The OLE DB Provider for AS/400 and VSAM does not use this value.
Mask Password: The OLE DB Provider for AS/400 and VSAM does not support this value.
Network Address: This property is used to locate the target host computer, specifically the TCP/IP address or TCP/IP host name/alias associated with
the DDM port. The network address is required when connecting using TCP/IP.
Network Port: This property is used to locate the target DDM service access port when connecting using TCP/IP. The default is the well-known DDM port address of 446.
Network Transport Library: The network transport dynamic link library property designates whether the provider connects with SNA LU6.2 or TCP/IP. The default value is SNA. If TCP/IP is selected, then values for Network Address and Network Port are required. If the default SNA is selected, then values for APPC Local LU Alias, APPC Mode Name, and APPC Remote LU Alias are required. TCP/IP connectivity to the mainframe is not supported.
PC Code Page: This property is required when processing binary data as character data. Unless the Process Binary as Character value is set, character data is converted based on the default ANSI code page configured in Windows. This parameter defaults to Latin 1 (1252).
Persist Security Info: Optionally, you can choose to save the password in the UDL file by selecting the Allow saving password check box.
WARNING: This option persists the authentication information in plain text within the UDL file.
Process Binary as Character: This option treats binary (CCSID 65535) data type fields as character data type fields on a per-data source basis. The Host CCSID and PC Code Page values are required input and output parameters.
Protection Level: The OLE DB Provider for AS/400 and VSAM does not support this value.
Repair Host Keys: This property provides for repair of invalid key offsets received from OS/400 when keys have been defined using the DDS "RENAME" clause. The default value is False.
Strict Validation: The default value is False.