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InformixSQLExpression

Inherits From:
EOSQLExpression : NSObject

Declared in: InformixEOAdaptor/InformixSQLExpression.h


Class Description

InformixSQLExpression defines how to build SQL statements for InformixChannels.


Bind Variables

The InformixAdaptor uses bind variables. A bind variable is a placeholder used in an SQL statement that is replaced with an actual value after the database server determines an execution plan. You use the following methods to operate on bind variables:


Class Methods


formatValue:forAttribute:

+ (NSString *)formatValue:(id)value forAttribute:(EOAttribute *)attribute

Overrides the EOSQLExpression method formatValue:forAttribute: to return a formatted string representation of value for attribute that is suitable for use in a SQL statement.


serverTypeIdForName

+ (int)serverTypeIdForName:(NSString *)typeName

Returns the Informix type code (such as InfDecimal, InfDate, or InfCHAR) for typeName (such as "DECIMAL", "DATE", or "CHAR").


Instance Methods


bindVariableDictionaryForAttribute:value:

- (NSMutableDictionary *)bindVariableDictionaryForAttribute:(EOAttribute *)attribute
value:value

Overrides the EOSQLExpression method bindVariableDictionaryForAttribute:value: to return the receiver's bind variable dictionaries. For more information on bind variables, see the discussion in the class description.

See also: - mustUseBindVariableForAttribute:, - shouldUseBindVariableForAttribute:


mustUseBindVariableForAttribute:

- (BOOL)mustUseBindVariableForAttribute:(EOAttribute *)attribute

Overrides the EOSQLExpression method mustUseBindVariableForAttribute: to return YES if the receiver must use bind variables for attribute, NO otherwise. A returned value of YES indicates that the underlying RDBMS requires that bind variables be used for attributes with attribute's external type.

See also: - bindVariableDictionaryForAttribute:value:, - shouldUseBindVariableForAttribute:


shouldUseBindVariableForAttribute:

- (BOOL)shouldUseBindVariableForAttribute:(EOAttribute *)attribute

Overrides the EOSQLExpression method shouldUseBindVariableForAttribute: to return YES if the receiver can provide a bind variable dictionary for attribute, NO otherwise. A returned value of YES indicates that the receiver should use bind variables for attributes with attribute's external type.

See also: - bindVariableDictionaryForAttribute:value:, - mustUseBindVariableForAttribute:



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