To open the Data Connection Resource properties box, choose Design - Design Properties.

Maximum number of concurrent connections
Set the maximum number of concurrent connections for the data connection. The default is one.

Block key field updates
This option is checked by default to prevent the value of a key field from changing. Key fields are used in back-end lookups.

Only update changed fields
This option prevents any updates to fields in the external data source unless the corresponding fields in the IBM® Lotus® Notes® document have been edited.

Use this option if you have triggers in the external system that monitor updates to individual columns of a table.

Enable conflict detection
This option ensures that the external data has not changed since the Notes document was opened. If it has changed, an update to the external data source will fail.

If this option is enabled and if you make changes to data in a Notes document and then save the document, you must exit the document before making any more changes -- even though you have saved the document.

Note When using an HTTP Server to access documents, "Conflict Detection" is not supported.

Space trimming
Specify whether to trim trailing spaces only on non-key fields or not at all.

Action on data mismatch
Specify what should happen when an error occurs. You can choose to return the error information, allow for a loss of precision, or allow for data to be truncated. The option you choose depends on the type of data being transmitted. For example, you might be willing to accept a loss of precision on numeric data in cases where your source application supports a higher degree of precision than the target Notes field. If you are dealing with long text strings, you might choose to truncate data where the two fields allow for different string lengths. Note that choosing data truncation might result in a loss of precision for numeric data. In cases where the complete integrity of the data is essential, you would opt for returning the error information. Note that data truncation is never an option for key fields, as that would prevent the application from working successfully.

Action on missing record
When a record you request is missing, you can set this option to return the error message, ignore the error and continue the data retrieval, or create an external record. For example, if the external table somehow gets out of synchronization and the DB2 row corresponding to a document is missing, this option would create the external record in DB2, allowing the document stub to still be used. Otherwise, an error message is returned, and the stub document cannot be opened or used.

Custom settings for specific applications

In addition to the general options listed above, some applications have additional custom settings.

Application	Setting	Usage
DB2	Data journaling	Select this option to enable SQL querying for a non-journaled data source. When the data source is non-journaled data -- for example, an IBM eServer iSeries database without journaling -- SQL queries are not supported unless this option is selected. This option sets the access mode to read only (transaction isolation level of uncommitted read), which enables SQL queries. The default access level is read-write (transaction isolation level of committed read).
ODBC	Single threading	Some ODBC drivers do not support multithreaded execution. When using such drivers, setting the Single Threaded option will protect the driver from multithreaded execution. Intersolv ODBC drivers release 3.01 and above are multithreaded. If erratic or unexplained behavior occurs, particularly at times of high application traffic, set this option to single threading and restart the activity.
OLE DB	Provider	The programmatic ID for the OLE DB provider to use.
OLE DB	Provider string	The required provider string values. This field maps to the OLE DB DBPROP_INIT_PROVIDERSTRING property.
OLE DB	Authentication service	The name of any authentication server used by the provider. This field maps to the OLEDBDBPROP_AUTH_INTEGRATED property.

See Also

Overview of Data Connection Resources
Establishing a data source resource for use with a DCR
Creating a database connection resource
Enabling connections to external databases
Using a data connection resource on a form

Glossary