Feature Service

Modules
	Connection To a Feature Source
	Describing a Feature Schema
	Feature Provider Registry
	Filters and Expressions
	Provider Capabilities
	Feature Service Classes

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Detailed Description

The Feature Service provides an abstraction layer for the storage and retrieval of feature data in a technology-independent way. You can use the API to determine which storage technologies are available and which capabilities they have. Access to the storage technology is modeled as a connection. For example, you can connect to a file and do simple insertions or connect to a relational database and do transaction-based operations.

The root methods are contained in the MgFeatureService class.

In general, you may do any of the following, subject to provider capability limitations:

• Determine which storage technologies are available (see MgFeatureService::GetFeatureProviders()),
• Determine which capabilities a feature provider has (see MgFeatureService::GetCapabilities()),
• Verify the connection property values (see MgFeatureService::GetConnectionPropertyValues()),
• Connect to a storage technology (feature provider) using either a resource identifier or a provider name and a connection string ,
• Describe the structure of feature data (see describe a feature schema ,
• Determine the spatial contexts available in the datastore (see MgFeatureService::GetSpatialContexts()),
• Insert feature data (see MgInsertFeatures),
• Select feature data (see MgFeatureService::SelectFeatures() and MgFeatureService::SelectAggregate()),
• Update feature data (see MgUpdateFeatures),
• Delete feature data (see MgDeleteFeatures),
• Execute SQL commands (see MgFeatureService::ExecuteSqlQuery() and MgFeatureService::ExecuteSqlNonQuery).