WebObjects 5.2

Package com.webobjects.eoaccess

Provides the data access mechanisms for the Enterprise Objects technology.

See:
          Description

Interface Summary
EOAdaptor.Delegate This interface defines a delegate to EOAdaptor to handle specific requests that are normally handled by EOAdaptor (or rather its subclass since EOAdaptor is an abstract class).
EOAdaptorChannel.Delegate EOAdaptorChannel invokes its delegate for nearly every operation that would affect data in the database server.
EOAdaptorContext.Delegate EOAdaptorContext invokes its delegate any time a transaction is begun, committed, or rolled back.
EODatabaseContext.Delegate This interface defines a delegate to EODatabaseContext to to handle specific requests that are ordinarily handled by EODatabaseContext.
EOModelGroup.ClassDelegate This interface defines a delegate to the EOModelGroup class to allow modification of the creation of the default model group.
EOModelGroup.Delegate This interface defines a delegate to EOModelGroup to allow instances to modify how the model group finds and loads models.
EOPropertyListEncoding The EOPropertyListEncoding interface declares methods that read and write objects to property lists, which are dictionaries containing String, NSDictionary, NSArray, and NSData objects.
EOQualifierSQLGeneration All qualifiers that can be used to generate SQL queries implement this interface.
EOSchemaGeneration This interface has been introduced to define API for generating database schemas from EOModel files.
EOSchemaSynchronization This interface has been introduced to define API to synchronize a database schema with a corresponding EOModel.
EOSchemaSynchronization.ColumnTypes The ColumnTypes interface is only used when implementing schema synchronization API for a custom adaptor.
EOSQLExpression.SQLValue This interface defines API for objects that can provide values for themselves to be used in SQL statements.
EOSynchronizationFactory.Delegate The Delegate interface for EOSynchronizationFactory is restricted to use by the EOModeler application and should not be implemented by others.
 

Class Summary
EOAccessArrayFaultHandler EOAccessArrayFaultHandler is a subclass of EOAccessGenericFaultHandler that implements a fault handler for an array of Enterprise Objects.
EOAccessFaultHandler EOAccessFaultHandler is a subclass of EOAccessGenericFaultHandler that implements an object fault for Enterprise Objects.
EOAccessGenericFaultHandler EOAccessGenericFaultHandler is an abstract class that helps an EOAccessFault to fire by fetching data using an EODatabaseContext.
EOAdaptor An EOAdaptor represents a single connection to a database server.
EOAdaptorChannel EOAdaptorChannel is an abstract class that provides its concrete subclasses with a structure for performing database operations.
EOAdaptorContext EOAdaptorContext is an abstract class that provides its concrete subclasses with a structure for handling database transactions.
EOAdaptorOperation An EOAdaptorOperation object represents a single primitive operation in a database server (lock, insert, update, or delete a particular row, or execute a stored procedure) as well as all the necessary information required to perform the operation.
EOAttribute An EOAttribute represents a column, field, or property in a database and associates an internal name with an external name or expression by which the property is known to the database.
EODatabase An EODatabase object represents a single database server.
EODatabaseChannel An EODatabaseChannel represents an independent communication channel to the database server.
EODatabaseContext EODatabaseContext is the basic EOObjectStore for the EOAccess Framework.
EODatabaseContext.DatabaseContextEvent DatabaseContextEvent is a subclass of EOEvent, the parent class for objects that gather information, such as duration or order of execution, about various operations in WebObjects.
EODatabaseDataSource EODatabaseDataSource is a concrete subclass of EODataSource, defined in EOControl.
EODatabaseOperation An EODatabaseOperation object represents an operation (insert, update, or delete) to perform on an Enterprise Object and all the necessary information required to perform that operation.
EOEntity An EOEntity describes a table in a database and associates a name internal to the Enterprise Objects Framework with an external name by which the table is known to the database.
EOEntityClassDescription EOEntityClassDescription is a subclass of the control layer's EOClassDescription.
EOJoin An EOJoin describes one source-destination attribute pair for an EORelationship.
EOModel An EOModel represents a mapping between a database schema and a set of classes based on the entity-relationship model for an application.
EOModelGroup An EOModelGroup represents an aggregation of related models.
EOProperty EOProperty is an abstract class that embodies the notion of an object that belongs to (is the property of) an EOEntity.
EOQualifierSQLGeneration.Support The abstract EOQualifierSQLGeneration.Support class provides basic functionality to subclasses that implement the EOQualifierSQLGeneration interface for specific qualifier types.
EORelationship An EORelationship describes an association between two entities, based on attributes of those two entities.
EOSQLExpression EOSQLExpression is an abstract superclass that defines how to build SQL statements for adaptor channels.
EOSQLExpressionFactory EOSQLExpressionFactory builds SQL statements for adaptor channels.
EOSQLQualifier Deprecated. The class EOSQLQualifier is deprecated.
EOStoredProcedure EOStoredProcedure encapsulates the information stored in an EOModel about a stored procedure which is stored in a database server.
EOSynchronizationFactory This class has been introduced to implement the interfaces EOSchemaGeneration and EOSchemaSynchronization, which were introduced in WebObjects 5.0.
EOUtilities This class is a collection of convenience methods intended to make common operations with EOF easier.
 

Exception Summary
EOGeneralAdaptorException A subclass of RuntimeException thrown by EOAccess.
EOObjectNotAvailableException A subclass of RuntimeException thrown when EOAccess fails to retrieve an object, typically in response to a failed or empty fetch.
EOUtilities.MoreThanOneException This exception is thrown from the methods in EOUtilities, indicating that multiple objects were found in a search that expected exactly one object as result.
 

Package com.webobjects.eoaccess Description

Provides the data access mechanisms for the Enterprise Objects technology.

Introduction

The EOAccess framework is one of a group of frameworks that make up the Enterprise Objects technology. The classes and interfaces that make up the EOAccess framework (also known as the access layer) allow your applications to interact with data stores (usually databases) at a high level of abstraction. The access layer is divided into two main parts:

Working with the access layer allows you to have a finer level of control over database operations than just using the control layer.


The Adaptor Level

The adaptor level deals with database rows by packaging them as dictionaries. The adaptor level is primarily made up of the following classes:


The Database Level

The database level is where enterprise objects are created from the dictionaries retrieved by the adaptor level. It's also where snapshotting is performed. The database level is primarily made up of the following classes:


The Modeling Classes

A model defines, in entity-relationship terms, the mapping between enterprise object classes and a database. The following are the principal modeling classes in the EOAccess framework:


Faulting

These classes implement or are used to implement object faulting:


Extensions of EOControl Classes

The EOAccess framework also has a number of other useful classes, including:


Delegates

A number of EOAccess classes have delegates. The delegate methods are defined in these interfaces:


Miscellaneous Classes and Interfaces


Last updated Fri Feb 21 13:15:00 PST 2003.

Copyright © 2003 Apple Computer, Inc.