PATH  WebObjects 4.0 Documentation > InformixEOAdaptor Reference



InformixAdaptor

Inherits From:
EOAdaptor : NSObject

Declared in: InformixEOAdaptor/InformixAdaptor.h


Class Description

An InformixAdaptor represents a single connection to an Informix database server, and is responsible for keeping login and model information, performing Informix-specific formatting of SQL expressions, and reporting errors.

The InformixAdaptor class has these restrictions: You can't have nested transactions, and the adaptor doesn't support full outer joins.


Method Types

Mapping external types to internal types
+ externalTypesWithModel:
+ internalTypeForExternalType:model:
Working with channels and contexts
- adaptorChannelClass
- adaptorContextClass
Testing the connection dictionary
- assertConnectionDictionaryIsValid
Getting information from the connection dictionary
- informixConnectionString
- informixDefaultForKey:
- connectionKeys
Getting the default expression class
- defaultExpressionClass
Verifying a qualifier type
- isValidQualifierType:model:
Error handling
- raiseInformixError:

Class Methods


externalTypesWithModel:

+ (NSArray *)externalTypesWithModel:(EOModel *)model

Overrides the EOAdaptor method externalTypesWithModel: to return the Informix database types.

See also: internalTypeForExternalType:model:


internalTypeForExternalType:model:

+ (NSString *)internalTypeForExternalType:(NSString *)externalType model:(EOModel *)model

Overrides the EOAdaptor method internalTypeForExternalType:model: to return the name of the Objective-C class used to represent values stored in the database as externalType.

See also: externalTypesWithModel:


Instance Methods


adaptorChannelClass

- (Class)adaptorChannelClass

Returns the InformixChannel class.


adaptorContextClass

- (Class)adaptorContextClass

Returns the InformixContext class.


assertConnectionDictionaryIsValid

- (void)assertConnectionDictionaryIsValid

Overrides the EOAdaptor method assertConnectionDictionaryIsValid to verify that the receiver can connect to the database with its connection dictionary. Briefly forms a connection to the server to validate the connection dictionary and then closes the connection (in other words, this method doesn't open a connecton to the database-that happens when the first adaptor channel is sent an openChannel message). The adaptor uses this method in conjunction with displaying a server login panel. Raises an exception if an error occurs.


connectionKeys

- (NSArray *)connectionKeys

Returns an NSArray containing the keys in the receiver's connection dictionary. You can use this method to prompt the user to supply values for the connection dictionary.


defaultExpressionClass

- (Class)defaultExpressionClass

Returns the InformixSQLExpression class.


informixConnectionString

- (NSString *)informixConnectionString

Returns the user name, password, and database name as a string suitable to be supplied as an argument to db_connect().


informixDefaultForKey:

- (NSString *)informixDefaultForKey:(NSString *)key

Returns the user default setting for key. To get this information it first checks the user defaults, and then the adaptor's internal defaults dictionary.


isValidQualifierType:model:

- (BOOL)isValidQualifierType:(NSString *)typeName model:(EOModel *)model

Overrides the EOAdaptor method isValidQualifierType:model: to return YES if an attribute of type typeName can be used in a qualifier (a SQL WHERE clause) sent to the database server, or NO otherwise. typeName is the name of a type as required by the database server, such as an Informix "VARCHAR".


raiseInformixError:

- (void)raiseInformixError:(NSString *)sqlString

Examines Informix structures for error flags and raises an exception if one is found. Extracts the error information in the connection structure and use it to build and raise an exception.





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