PATH WebObjects 4.0 Documentation > EOAccess Reference

EOSQLQualifier

Inherits From:
EOQualifier : NSObject

Conforms To: EOQualifierSQLGeneration, NSObject (NSObject)

Declared in: EOAccess/EOSQLQualifier.h

Class Description

EOSQLQualifier is a subclass of EOQualifier that contains unstructured text that can be transformed into an SQL expression. EOSQLQualifier is provided for backwards compatibility with pre-2.0 Enterprise Objects Framework releases and to provide a way to create SQL expressions with any arbitrary SQL. EOSQLQualifier formats are not parsed, they simply perform substitution for keys and format characters. The qualifying information is expressed in the database server's query language (nearly always SQL), and you're responsible for ensuring that the query language statement is valid for your database server. EOSQLQualifiers can't be evaluated against objects in memory. As a result, you should use EOQualifier whenever possible and only use EOSQLQualifier in cases that absolutely require it.

You create an SQL qualifier using alloc... and initWithEntity:qualifierFormat:. This method takes as arguments the root entity for the qualifier and a format string like that used with the standard creation method qualifierWithQualifierFormat:.

Note: Because an SQL qualifier must be rooted to an entity, you can't use qualifierWithQualifierFormat: to create EOSQLQualifier objects.

Adopted Protocols

EOQualifierSQLGeneration - schemaBasedQualifierWithRootEntity: - sqlStringForSQLExpression:

Class Methods

qualifierWithQualifierFormat:

+ (EOQualifier *)qualifierWithQualifierFormat:(NSString *)format, ...

Raises an exception. An EOSQLQualifier must be created with an entity, and this method does not provide one. Use alloc... and initWithEntity:qualifierFormat: to create an EOSQLQualifier.

Instance Methods

initWithEntity:qualifierFormat:

- initWithEntity:(EOEntity *)entity qualifierFormat:(NSString *)qualifierFormat, ...

Initializes a newly allocated EOSQLQualifier rooted in entity and built from a format string. qualifierFormat is a printf()-style format string like that used with EOQualifier's qualifierWithQualifierFormat: method. This is the designated initializer for the EOSQLQualifier class. Returns self if qualifierFormat is successfully parsed, nil otherwise.