RWDBExprFuncDef2 Class Reference
[Expressions]

Specialization of the base class RWDBExprFormDefinition used to define SQL functions that take 2 parameters. More...

#include <rw/db/func.h>

Inheritance diagram for RWDBExprFuncDef2:

List of all members.

Public Member Functions
	RWDBExprFuncDef2 (const RWCString &functionName)
virtual RWDBExpr	operator() (const RWDBExpr &x1, const RWDBExpr &x2)
Private Member Functions
virtual RWDBExpr	operator() ()
virtual RWDBExpr	operator() (const RWDBExpr &)
virtual RWDBExpr	operator() (const RWDBExpr &, const RWDBExpr &, const RWDBExpr &)
virtual RWDBExpr	operator() (const RWDBExpr &, const RWDBExpr &, const RWDBExpr &, const RWDBExpr &)

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Detailed Description

RWDBExprFuncDef2 is a specialization of the base class RWDBExprFormDefinition. This class provides a simplified mechanism for defining SQL functions taking 2 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>
 
 RWDBExprFuncDef2 myFunc("myFunc");

Related Classes

RWDBCritFuncDef2 provides a parallel mechanism for defining an RWDBCriterion, rather than an RWDBExpr.

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

See RWDBExpr for details on SQL expressions in the DB Interface Module, as well as for a complete listing of predefined SQL functions.

Examples

Please refer to the example in RWDBExprFuncDef3.

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Constructor & Destructor Documentation

RWDBExprFuncDef2::RWDBExprFuncDef2

(

const RWCString &

functionName

)

Creates an RWDBExprFuncDef2 for a functional expression that takes two parameters. After such an RWDBExprFuncDef2 is instantiated, functionName may be used as though it were a predefined function.

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Member Function Documentation

virtual RWDBExpr RWDBExprFuncDef2::operator()	(	const RWDBExpr &	,
		const RWDBExpr &	,
		const RWDBExpr &	,
		const RWDBExpr &
	)			[private, virtual]

Not applicable to this class. This class defines SQL functions taking two parameters.

Reimplemented from RWDBExprFormDefinition.

virtual RWDBExpr RWDBExprFuncDef2::operator()	(	const RWDBExpr &	,
		const RWDBExpr &	,
		const RWDBExpr &
	)			[private, virtual]

Not applicable to this class. This class defines SQL functions taking two parameters.

Reimplemented from RWDBExprFormDefinition.

virtual RWDBExpr RWDBExprFuncDef2::operator()

(

const RWDBExpr &

)

[private, virtual]

Not applicable to this class. This class defines SQL functions taking two parameters.

Reimplemented from RWDBExprFormDefinition.

virtual RWDBExpr RWDBExprFuncDef2::operator()

(

)

[private, virtual]

Not applicable to this class. This class defines SQL functions taking two parameters.

Reimplemented from RWDBExprFormDefinition.

virtual RWDBExpr RWDBExprFuncDef2::operator()	(	const RWDBExpr &	x1,
		const RWDBExpr &	x2
	)			[virtual]

Returns an RWDBExpr in the form of a function with two parameters whose name is the name which was passed to self's constructor.

Reimplemented from RWDBExprFormDefinition.