MySQL 8.0.31
Source Code Documentation
RefOrNullIterator Class Referencefinal

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:
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Public Member Functions

 RefOrNullIterator (THD *thd, TABLE *table, TABLE_REF *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 IteratorProfilerGetProfiler () const
 Get profiling data for this iterator (for 'EXPLAIN ANALYZE'). More...
 
virtual void SetOverrideProfiler ([[maybe_unused]] const IteratorProfiler *profiler)
 
virtual RowIteratorreal_iterator ()
 If this iterator is wrapping a different iterator (e.g. More...
 
virtual const RowIteratorreal_iterator () const
 

Private Attributes

TABLE_REF *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)
 
TABLEtable () const
 
- Protected Member Functions inherited from RowIterator
THDthd () 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,
TABLE_REF 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 TABLE_REF) 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
0OK
-1End of records
1Error

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

TABLE_REF* const RefOrNullIterator::m_ref
private

◆ m_use_order

const bool RefOrNullIterator::m_use_order
private

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