RWDBCritFuncDef0 Class Reference
[Expressions]

Specialization of the base class RWDBCritFormDefinition used for defining SQL functions taking no parameters. More...

#include <rw/db/func.h>

Inheritance diagram for RWDBCritFuncDef0:

List of all members.

Public Member Functions
	RWDBCritFuncDef0 (const RWCString &functionName)
virtual RWDBCriterion	operator() ()
Private Member Functions
virtual RWDBCriterion	operator() (const RWDBExpr &)
virtual RWDBCriterion	operator() (const RWDBExpr &, const RWDBExpr &)
virtual RWDBCriterion	operator() (const RWDBExpr &, const RWDBExpr &, const RWDBExpr &)
virtual RWDBCriterion	operator() (const RWDBExpr &, const RWDBExpr &, const RWDBExpr &, const RWDBExpr &)

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Detailed Description

RWDBCritFuncDef0 is a specialization of the base class RWDBCritFormDefinition. This class provides a simplified mechanism for defining SQL functions taking no parameters. Unlike the base class, this class does not require positional placeholders in its function definitions. Also, since the number of required parameters is fixed, compile-time checking can be done on the number of parameters actually passed.

Synopsis

 #include <rw/db/func.h>
 
 RWDBCritFuncDef0 myFunc("myFunc");

Related Classes

RWDBExprFuncDef0 provides a parallel mechanism for defining an RWDBExpr, rather than using an RWDBCriterion.

The RWDBCritFormDefinition base class may be used directly to gain additional flexibility.

See RWDBCriterion for details on SQL WHERE clauses in the DB Interface Module.

Examples

Please refer to the example in RWDBCritFuncDef1.

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Constructor & Destructor Documentation

RWDBCritFuncDef0::RWDBCritFuncDef0

(

const RWCString &

functionName

)

Creates an RWDBCritFuncDef0 for a functional expression that takes no parameters. After such an RWDBCritFuncDef0 is instantiated, functionName may be used as though it were a predefined function.

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Member Function Documentation

virtual RWDBCriterion RWDBCritFuncDef0::operator()	(	const RWDBExpr &	,
		const RWDBExpr &	,
		const RWDBExpr &	,
		const RWDBExpr &
	)			[private, virtual]

Not applicable to this class. This class defines SQL functions taking no parameters.

Reimplemented from RWDBCritFormDefinition.

virtual RWDBCriterion RWDBCritFuncDef0::operator()	(	const RWDBExpr &	,
		const RWDBExpr &	,
		const RWDBExpr &
	)			[private, virtual]

Not applicable to this class. This class defines SQL functions taking no parameters.

Reimplemented from RWDBCritFormDefinition.

virtual RWDBCriterion RWDBCritFuncDef0::operator()	(	const RWDBExpr &	,
		const RWDBExpr &
	)			[private, virtual]

Not applicable to this class. This class defines SQL functions taking no parameters.

Reimplemented from RWDBCritFormDefinition.

virtual RWDBCriterion RWDBCritFuncDef0::operator()

(

const RWDBExpr &

)

[private, virtual]

Not applicable to this class. This class defines SQL functions taking no parameters.

Reimplemented from RWDBCritFormDefinition.

virtual RWDBCriterion RWDBCritFuncDef0::operator()

(

)

[virtual]

Returns an RWDBCriterion in the form of a function with no parameter whose name is the name that was passed to self's constructor.

Reimplemented from RWDBCritFormDefinition.