CDbColSet Class Reference

#include <d32dbms.h>

Link against: edbms.lib

class CDbColSet : public CBase

Inherits from

CDbColSet

Public Member Functions
	CDbColSet()
	~CDbColSet()
IMPORT_C CDbColSet &	AddL(const TDbCol &)
void	Clear()
IMPORT_C const TDbCol *	Col(const TDesC &)
IMPORT_C TDbColNo	ColNo(const TDesC &)
TInt	Count()
IMPORT_C CDbColSet *	NewL()
IMPORT_C CDbColSet *	NewLC()
IMPORT_C void	Remove(const TDesC &)
const TDbCol &	operator[](TDbColNo)

Inherited Functions
	CBase::CBase()
	CBase::Delete(CBase *)
	CBase::Extension_(TUint,TAny &,TAny )
	CBase::operator new(TUint)
	CBase::operator new(TUint,TAny *)
	CBase::operator new(TUint,TLeave)
	CBase::operator new(TUint,TLeave,TUint)
	CBase::operator new(TUint,TUint)
	CBase::~CBase()

Detailed Description

Manages a set of column definitions which describe a table or rowset structure. Column definitions can be added and removed. The set can be iterated over, and ordinals for a column can be looked up.

The class is not intended for user derivation.

Constructor & Destructor Documentation

CDbColSet ( )

IMPORT_C

CDbColSet

(

)

Constructs an empty column set.

~CDbColSet ( )

IMPORT_C

~CDbColSet

(

)

Frees resources owned by the object.

Member Function Documentation

AddL ( const TDbCol & )

IMPORT_C CDbColSet &

AddL

(

const TDbCol &

aCol

)

Adds a column to the column set.

Parameter	Description
aCol	The column to add to the set.

Returns: A reference to this object.

Clear ( )

void

Clear

(

)

[inline]

Removes all of the columns from the column set.

Col ( const TDesC & )

IMPORT_C const TDbCol *

Col

(

const TDesC &

aColName

)

const

Returns a named column definition in the set. If such a column does not exist in the set NULL is returned.

Parameter	Description
aColName	The name of the column to find.

Returns: A pointer to the column definition found, or NULL.

ColNo ( const TDesC & )

IMPORT_C TDbColNo

ColNo

(

const TDesC &

aColName

)

const

Returns the ordinal for a particular column name in this column set. If such a column does not exist in the set the special ordinal KDbNullColNo is returned.

This function is particularly important when accessing data through a rowset. If the set of columns to be returned by a rowset is not explicitly specified, no assumptions should be made about the ordering of the columns returned. In such a case, in order to access the column data a column ordinal is required, and this can be obtained by using this function on the column set returned by RDbRowSet::ColSetL().

Parameter	Description
aColName	The name of the column to find.

Returns: The ordinal number of the column.

Count ( )

TInt

Count

(

)

const [inline]

Returns the number of column definitions in the set.

Note that using a TDbColSetIter is another way to iterate through the contents of a CDbColSet.

Returns: The number of columns in the columns set.

NewL ( )

IMPORT_C CDbColSet *

NewL

(

)

[static]

Constructs a new empty column set and returns a pointer to it.

Returns: A pointer to the column set object.

NewLC ( )

IMPORT_C CDbColSet *

NewLC

(

)

[static]

Constructs a new empty column set and returns a pointer to it placing the pointer onto the cleanup stack. This allows the column set object and allocated resources to be cleaned up if a subsequent leave occurs.

Returns: A pointer to the column set object.

Remove ( const TDesC & )

IMPORT_C void

Remove

(

const TDesC &

aColName

)

Removes the named column from the set.

Parameter	Description
aColName	The name of the column to remove from the set.

operator[] ( TDbColNo )

const TDbCol &

operator[]

(

TDbColNo

aCol

)

const [inline]

Returns a column definition by its ordinal number in the set.

Note that using a TDbColSetIter is another way to iterate through the contents of a CDbColSet.

Parameter	Description
aCol	The ordinal number of the column in the set. Columns in a column set are numbered from 1 to Count(), unlike Symbian OS array classes. Ordinal 0 is reserved to represent the invalid column number KDbNullColNo.

Returns: The column definition requested.