# Geomedia MDB database

GDAL/OGR >= 1.9.0

OGR optionally supports reading Geomedia .mdb files via ODBC. Geomedia is a Microsoft Access database with a set of tables defined by Intergraph for holding geodatabase metadata, and with geometry for features held in a BLOB column in a custom format. This drivers accesses the database via ODBC but does not depend on any Intergraph middle-ware.

Geomedia .mdb are accessed by passing the file name of the .mdb file to be accessed as the data source name. On Windows, no ODBC DSN is required. On Linux, there are problems with DSN-less connection due to incomplete or buggy implementation of this feature in the MDB Tools package, So, it is required to configure Data Source Name (DSN) if the MDB Tools driver is used (check instructions below).

In order to facilitate compatibility with different configurations, the GEOMEDIA_DRIVER_TEMPLATE Config Option was added to provide a way to programmatically set the DSN programmatically with the filename as an argument. In cases where the driver name is known, this allows for the construction of the DSN based on that information in a manner similar to the default (used for Windows access to the Microsoft Access Driver).

OGR treats all feature tables as layers. Most geometry types should be supported (arcs are not yet). Coordinate system information is not currently supported.

Currently the OGR Personal Geodatabase driver does not take advantage of spatial indexes for fast spatial queries.

By default, SQL statements are passed directly to the MDB database engine. It's also possible to request the driver to handle SQL commands with OGR SQL engine, by passing "OGRSQL" string to the ExecuteSQL() method, as name of the SQL dialect.

## How to use Geomedia driver with unixODBC and MDB Tools (on Unix and Linux)

Starting with GDAL/OGR 1.9.0, the MDB driver is an alternate way of reading Geomedia .mdb files without requiring unixODBC and MDB Tools

Refer to the similar section of the PGeo driver. The prefix to use for this driver is Geomedia:

## See also

- MDB driver page