Introduction

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Connection strings are used when the SQLDriverConnect and SQLBrowseConnect ODBC API functions are called. They may specify as little as a data source name or as much as an entire data source configuration. The SQLDriverConnect function will interactively complete a connection string, if necessary and if the calling program indicates that it wants this behavior, by prompting the user for the missing information. On the other hand, the SQLBrowseConnect function will do so programmatically by iteratively interacting with the calling program. For more information on the SQLDriverConnect and SQLBrowseConnect API calls, please refer to the ODBC Programmers Reference from Microsoft. For more information on what function calls are used in your application program, please ask the vendor of the application program being used.

Pre-Configured Data Source Connection Strings

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Connection strings that connect to a pre-configured data source, do so by specifying the DSN keyword in the connection string:

DSN=MyDataSource

Any other keywords that are specified in the connection string are overridden with the settings present in the data source configuration for the specified data source.

In addition, you can also use the FILEDSN keyword to load a data source configuration from a specific file instead of the registry:

FILEDSN=c:\windows\temp\mydatasource.dsn

That will load the configuration values from the mydatasource.dsn file. For more information on using the FILEDSN keyword, please refer to the ODBC Programmers Reference from Microsoft.

Direct Connection Strings

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Direct connection strings bypass using a pre-configured data source altogether and specify all of the keywords necessary to configure and access a given data source. The first keyword in a direct connection string must always be the special DRIVER keyword. For the DBISAM ODBC Driver, it would look like this:

DRIVER={DBISAM 4 ODBC Driver}

Notice the use of the required braces {} around the DRIVER keyword.

The keywords that can be used with direct connection strings and the DBISAM ODBC driver are listed below. Here is an example direct connection string that connects to a remote DBISAM database server and a database called "Elevate" (case-insensitive) on that database server:

DRIVER={DBISAM 4 ODBC Driver};
ConnectionType=Remote;
CatalogName=Elevate;
RemoteIPAddress=192.168.0.28

DBISAM Connection String Keywords

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The following keywords are used with connection strings. The only required keyword for local connections is the CatalogName keyword. For remote connections, the required keyword is either the RemoteIPAddress or RemoteHostName keyword.