RefOrNullIterator Class Reference

Like RefIterator, but after it's returned all its rows, will also search for rows that match NULL, i.e., WHERE column=<ref> OR column IS NULL. More...

#include <ref_row_iterators.h>

Inheritance diagram for RefOrNullIterator:

Public Member Functions
	RefOrNullIterator (THD *thd, TABLE *table, Index_lookup *ref, bool use_order, double expected_rows, ha_rows *examined_rows)
	Reading of key with key reference and one part that may be NULL. More...
	~RefOrNullIterator () override
bool	Init () override
	Initialize or reinitialize the iterator. More...
int	Read () override
	Read a single row. More...
Public Member Functions inherited from TableRowIterator
	TableRowIterator (THD *thd, TABLE *table)
void	UnlockRow () override
	The default implementation of unlock-row method of RowIterator, used in all access methods except EQRefIterator. More...
void	SetNullRowFlag (bool is_null_row) override
	Mark the current row buffer as containing a NULL row or not, so that if you read from it and the flag is true, you'll get only NULLs no matter what is actually in the buffer (typically some old leftover row). More...
void	StartPSIBatchMode () override
	Start performance schema batch mode, if supported (otherwise ignored). More...
void	EndPSIBatchModeIfStarted () override
	Ends performance schema batch mode, if started. More...
Public Member Functions inherited from RowIterator
	RowIterator (THD *thd)
virtual	~RowIterator ()=default
	RowIterator (const RowIterator &)=delete
	RowIterator (RowIterator &&)=default
virtual const IteratorProfiler *	GetProfiler () const
	Get profiling data for this iterator (for 'EXPLAIN ANALYZE'). More...
virtual void	SetOverrideProfiler (const IteratorProfiler *profiler)
virtual RowIterator *	real_iterator ()
	If this iterator is wrapping a different iterator (e.g. More...
virtual const RowIterator *	real_iterator () const

Private Attributes
Index_lookup *const	m_ref
const bool	m_use_order
bool	m_reading_first_row
const double	m_expected_rows
ha_rows *const	m_examined_rows
bool	m_is_mvi_unique_filter_enabled

Additional Inherited Members
Protected Member Functions inherited from TableRowIterator
int	HandleError (int error)
void	PrintError (int error)
TABLE *	table () const
Protected Member Functions inherited from RowIterator
THD *	thd () const

Detailed Description

Like RefIterator, but after it's returned all its rows, will also search for rows that match NULL, i.e., WHERE column=<ref> OR column IS NULL.

Constructor & Destructor Documentation

RefOrNullIterator()

RefOrNullIterator::RefOrNullIterator	(	THD *	thd,
		TABLE *	table,
		Index_lookup *	ref,
		bool	use_order,
		double	expected_rows,
		ha_rows *	examined_rows
	)

Reading of key with key reference and one part that may be NULL.

~RefOrNullIterator()

RefOrNullIterator::~RefOrNullIterator ( )

override

Member Function Documentation

Init()

bool RefOrNullIterator::Init ( )

overridevirtual

Initialize or reinitialize the iterator.

You must always call Init() before trying a Read() (but Init() does not imply Read()).

You can call Init() multiple times; subsequent calls will rewind the iterator (or reposition it, depending on whether the iterator takes in e.g. a Index_lookup) and allow you to read the records anew.

Implements RowIterator.

Read()

int RefOrNullIterator::Read ( )

overridevirtual

Read a single row.

The row data is not actually returned from the function; it is put in the table's (or tables', in case of a join) record buffer, ie., table->records[0].

Return values

0	OK
-1	End of records
1	Error

Implements RowIterator.

Member Data Documentation

m_examined_rows

ha_rows* const RefOrNullIterator::m_examined_rows

private

m_expected_rows

const double RefOrNullIterator::m_expected_rows

private

m_is_mvi_unique_filter_enabled

bool RefOrNullIterator::m_is_mvi_unique_filter_enabled

private

m_reading_first_row

bool RefOrNullIterator::m_reading_first_row

private

m_ref

Index_lookup* const RefOrNullIterator::m_ref

private

m_use_order

const bool RefOrNullIterator::m_use_order

private

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

• sql/iterators/ref_row_iterators.h
• sql/iterators/ref_row_iterators.cc