| API Reference | OSGeo FDO Provider for ODBC |
Introduction
The Feature Data Objects (FDO) API provides access to data in a data store. A provider is a specific implementation of the FDO API that provides access to data in a particular data store. The FDO Provider for ODBC provides FDO with access to an ODBC-based data store.
The FDO Provider for ODBC can access simple x, y, z feature objects that can run in a multi-platform environment, including Windows, Linux, and UNIX.
The FDO Provider for ODBC has the following characteristics:
- The FDO Provider for ODBC supports the definition of one or more feature classes in terms of any relational database table that contains an X, Y, and optionally, Z columns.
- Metadata--that maps the table name, and X, Y, and optionally, Z columns to a feature class--is maintained outside the database in a configuration file. This information, in conjunction with the table structure in the database, provides the definition of the feature class.
- The x, y, and z locations of objects are stored in separate properties in the primary object definition of a feature, but are accessible through a single class property Geometry.
- Read-only access is provided to pre-existing data defined and populated through 3rd party applications (that is, FDO Provider for ODBC will not be responsible for defining the physical schema of the data store nor for populating the object data).
- The schema configuration of the data store is provided to the FDO Provider for ODBC through an optional XML file containing the Geographic Markup Language (GML) definition of the schema that maps tables and columns in the data store to feature classes and property mappings in the FDO data model.
- Note:
- Microsoft Excel (must have at least one named range; do not use DATABASE or other reserved words as a range name)
For more information about setting up an ODBC data store in AutoCAD Map 3D 2008 and configuring Excel for database ranges, see the 'Managing Data' topic in the AutoCAD Map 3D User's Guide (acmap.chm).
For ODBC, only a point geometry (X, Y, and optionally, Z columns define a point) is supported. The default column names are X, Y, and Z, but when you pick the columns to represent these, you override the defaults. In AutoCAD Map 3D 2008, this information is stored in the map file itself, so if you go through the same process in another map, you will need to override the settings again in the same way.
There is no spatial indexing. Object locations are stored in separate properties in the object definition.
The existing schema is used, and you cannot add, change, or delete it, nor can you add FDO metadata to the data store.
When you set up a Data Source Name for your ODBC data store (by adding a DSN in Windows), you will need to specify certain configuration options, depending on the type of ODBC data store you use. The connection information (Login ID and password) you enter here is used only for defining the DSN, and not at connection time with the ODBC provider.
- Note:
- For MySQL, make sure you have installed the MySQL driver from MyODBC 3.51. You can find it at http://dev.mysql.com/downloads/connector/odbc/3.51.html.
For more information, see The Essential FDO (FET_TheEssentialFDO.pdf) and the FDO Developer's Guide (FDG_FDODevGuide.pdf).
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