casacore::TableExprId Class Reference

The identification of a TaQL selection subject. More...

#include <TableExprId.h>

Inheritance diagram for casacore::TableExprId:

Public Member Functions
	TableExprId ()
	Default constructor sets rownr to -1. More...
	TableExprId (rownr_t rowNumber)
	Construct it from a row number. More...
	TableExprId (const RecordInterface &)
	Construct it from a Record object. More...
	TableExprId (const TableExprData &data)
	Construct it from pointers to data. More...
	~TableExprId ()
Bool	byRow () const
	Is the id given by row number? More...
Bool	byRecord () const
	Is the id given as a RecordInterface? More...
Bool	byData () const
	Is the id given as a TableExprData? More...
Int64	rownr () const
	Get the row number. More...
const RecordInterface &	record () const
	Get the Record reference. More...
const TableExprData &	data () const
	Get the data reference. More...
void	setRownr (rownr_t rownr)
	Set the row number. More...
void	setRecord (const RecordInterface &)
	Set the record. More...

Private Attributes
Int	type_p
union {
Int64   row_p
const RecordInterface *   record_p
const TableExprData *   data_p
};

Detailed Description

The identification of a TaQL selection subject.

Intended use:

Public interface

Review Status

Reviewed By:

UNKNOWN

Date Reviewed:

before2004/08/25

Prerequisite

• TableExprNode.

Synopsis

This class provides the user the ability to identify the data objects to test in a TaQL expression. In this way a TaQL expression is not limited to tables, but can be used for any set of data. Three types are available:

1. A row number giving the row to test in a table. It also contains a sequence number (0..n) which is used to get the result calculated by aggregate functions.
2. A RecordInterface object giving the record to test.
3. A TableExprData object giving the abstract base class of an object holding the data to test. In this way any data can be used.

The TaQL expression must be setup with this in mind by constructing the appropriate TableExprNode leaf objects.
When used for tables, the function Table::col should be used to create the TableExprNode objects for the table columns to be used in the expression.
For the other cases class TableExprNodeRecordField has to be used to know the index of the fields in the expression. It uses a record (description) for this purpose.

Example

Motivation

This class makes it possible that TaQL can be used in a very versatile way.

Definition at line 97 of file TableExprId.h.

Constructor & Destructor Documentation

casacore::TableExprId::TableExprId ( )

inline

Default constructor sets rownr to -1.

Definition at line 150 of file TableExprId.h.

casacore::TableExprId::TableExprId ( rownr_t  rowNumber )

inline

Construct it from a row number.

Definition at line 155 of file TableExprId.h.

casacore::TableExprId::TableExprId ( const RecordInterface &  record )

inline

Construct it from a Record object.

Definition at line 160 of file TableExprId.h.

casacore::TableExprId::TableExprId ( const TableExprData &  data )

inline

Construct it from pointers to data.

Definition at line 165 of file TableExprId.h.

casacore::TableExprId::~TableExprId ( )

inline

Definition at line 112 of file TableExprId.h.

Member Function Documentation

Bool casacore::TableExprId::byData ( ) const

inline

Is the id given as a TableExprData?

Definition at line 205 of file TableExprId.h.

References type_p.

Bool casacore::TableExprId::byRecord ( ) const

inline

Is the id given as a RecordInterface?

Definition at line 200 of file TableExprId.h.

References type_p.

Bool casacore::TableExprId::byRow ( ) const

inline

Is the id given by row number?

Definition at line 195 of file TableExprId.h.

References type_p.

const TableExprData & casacore::TableExprId::data ( ) const

inline

Get the data reference.

Definition at line 180 of file TableExprId.h.

References data_p.

const RecordInterface & casacore::TableExprId::record ( ) const

inline

Get the Record reference.

Definition at line 175 of file TableExprId.h.

References record_p.

Referenced by setRecord().

Int64 casacore::TableExprId::rownr ( ) const

inline

Get the row number.

Definition at line 170 of file TableExprId.h.

References row_p.

Referenced by setRownr().

void casacore::TableExprId::setRecord ( const RecordInterface &  record )

inline

Set the record.

Definition at line 190 of file TableExprId.h.

References record(), and record_p.

void casacore::TableExprId::setRownr ( rownr_t  rownr )

inline

Set the row number.

Definition at line 185 of file TableExprId.h.

References row_p, and rownr().

Referenced by casacore::TableParseSelect::doGroupByAggrSingleKey().

Member Data Documentation

union { ... }

const TableExprData* casacore::TableExprId::data_p

Definition at line 144 of file TableExprId.h.

Referenced by data().

const RecordInterface* casacore::TableExprId::record_p

Definition at line 143 of file TableExprId.h.

Referenced by record(), and setRecord().

Int64 casacore::TableExprId::row_p

Definition at line 142 of file TableExprId.h.

Referenced by rownr(), and setRownr().

Int casacore::TableExprId::type_p

private

Definition at line 140 of file TableExprId.h.

Referenced by byData(), byRecord(), and byRow().

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The documentation for this class was generated from the following file:

• tables/TaQL/TableExprId.h