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Using the InterSystems ODBC Driver
Overview
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InterSystems provides ODBC drivers to enable you to access InterSystems databases via an ODBC connection. To use ODBC, install and configure the InterSystems ODBC client driver, then define one or more DSNs to refer to InterSystems databases. Your application can use an InterSystems DSN in the same way it would use any other DSN.
Installation
To use an InterSystems database as an ODBC data source, you should first ensure that the InterSystems ODBC client driver has been installed. The following options are available:
You must also define DSNs (Data Source Names) to provide your ODBC-aware applications with information needed to connect to InterSystems databases. Each InterSystems database can be represented by multiple DSNs, each of which can support multiple connections. See Using an InterSystems Database as an ODBC Data Source on Windows or Using an InterSystems Database as an ODBC Data Source on UNIX® for OS-specific instructions on how to perform these tasks.
Note:
On Windows, InterSystems IRIS IDs use the Large Number (BigInt) datatype, so ODBC client applications must have Large Number support. For example, instances of Access 2016 previous to build 16.0.7812 will display row data as #Deleted. This may also happen if Large Number support is not turned on in the Access Settings for the current database.
ODBC Driver Support
The InterSystems ODBC drivers are compliant with ODBC 3.5.
InterSystems ODBC supports the following ODBC driver managers:
For more complete information, including specific supported databases, see the online InterSystems Supported Platforms document for this release.
An Overview of ODBC
An ODBC system has the following components:
Note:
For a particular vendor database, that vendor may offer its own version of the ODBC client driver for that platform. Oracle, for example, supplies its own ODBC driver for use with Oracle databases on Windows. This may be preferred in some cases because the vendor driver may take advantage of its knowledge of how the database works internally to optimize performance or enhance reliability.
ODBC Connection Details
For an application to connect to a database via ODBC, the application must generally provide the following connection details:
In most cases, this information is stored within a DSN, which has a logical name for use within the client application. The DSN may or may not include login credentials, which can also be stored in the database initialization file, or not stored at all.
The DSNs must be registered with the ODBC driver manager.
In practice, a connection is established as follows:
  1. A client application includes ODBC calls that attempt to connect to a particular DSN. A client application is linked to an ODBC driver manager, which accepts the calls.
  2. The ODBC driver manager reads the initialization file to obtain the location of the ODBC client driver and load the client driver into memory.
  3. Once loaded into memory, the ODBC client driver uses the ODBC initialization file to locate connection information for the DSN, as well as other information. Using this information, the client driver connects to the specified database.
  4. Having established the connection, the client driver maintains communications with the database server.


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Content Date/Time: 2019-02-18 00:56:44