A <query primary> which is a parenthesized query expression (aka qe) body with order by clause and/or limit/offset clause and the qe body is not a binary set operation (union, except, intersect), but is viewed here as a degenerate set operation; i.e. More...

#include <query_term.h>

Inheritance diagram for Query_term_unary:

[legend]

Public Member Functions
	Query_term_unary (MEM_ROOT mem_root, Query_term t)
	Constructor. More...

Query_term_type	term_type () const override
	Get the node tree type. More...

const char *	operator_string () const override
	Get the node type description. More...

void	debugPrint (int level, std::ostringstream &buf) const override
	Print the tree rooted at this node to buf. More...

Public Member Functions inherited from Query_term_set_op
Query_block *	query_block () const override
	Getter for m_block, q.v. More...

bool	set_block (Query_block *b)
	Setter for m_block, q.v. More...

void	label_children () override
	Set the correct value of `Query_term::m_sibling_idx` recursively for set operations. More...

size_t	child_count () const override
	Get the number of children this node has. More...

bool	open_result_tables (THD *thd, int level) override
	Open tmp tables for the tree of set operation query results, by recursing. More...

void	cleanup (bool full) override
	Reset resources used. More...

void	destroy_tree () override
	Destroy the query term tree structure. More...

bool	has_mixed_distinct_operators ()
	Check if this set operation has a mix of DISTINCT and ALL. More...

bool	is_unary () const
	Check if this term is a unary set operation. More...

Mem_root_array< MaterializePathParameters::QueryBlock >	setup_materialize_set_op (THD thd, TABLE dst_table, bool union_distinct_only, bool calc_found_rows)
	Sets up each() query block in this query expression for materialization into the given table by making a materialization parameter for each block () modulo union_distinct_only. More...

Public Member Functions inherited from Query_term
Query_term *	pushdown_limit_order_by (Query_term_set_op *parent=nullptr)
	Called after contextualization to simplify query, c.f. More...

bool	validate_structure (const Query_term *parent, int depth=0) const
	Return true if structure is too deep, i.e. More...

std::pair< bool, bool >	redundant_order_by (Query_block *block, int level)
	Determine if we have a redundant ORDER BY in block. More...

virtual	~Query_term ()=default
	Node destructor. More...

Query_term_set_op *	parent () const
	Getter for m_parent, q.v. More...

void	set_sibling_idx (uint idx)
	Setter for `m_sibling_idx`, q.v. More...

uint	sibling_idx ()
	Getter for `m_sibling_idx`, q.v. More...

void	printPointers (std::ostringstream &buf) const
	Print the pointer of this node and its parent to buf. More...

void	set_setop_query_result (Query_result *rs)
	Setter for m_setop_query_result, q.v. More...

Query_result *	setop_query_result ()
	Getter for m_setop_query_result, q.v. More...

Query_result_union *	setop_query_result_union ()
	Getter for m_setop_query_result, q.v. Use only if we can down cast. More...

void	cleanup_query_result (bool full)
	Cleanup m_setop_query_result, q.v. More...

void	set_owning_operand ()
	Setter for m_owning_operand, q.v. More...

bool	owning_operand ()
	Getter for m_owning_operand, q.v. More...

void	set_result_table (Table_ref *tl)
	Setter for m_result_table, q.v. More...

Table_ref &	result_table ()
	Getter for m_result_table, q.v. More...

void	set_fields (mem_root_deque< Item * > *fields)

mem_root_deque< Item * > *	fields ()

Additional Inherited Members
Static Public Member Functions inherited from Query_term
static void	indent (int level, std::ostringstream &buf)
	Print blank space indentation (unit: two) to buf according to level. More...

static void	print_order (const THD thd, String str, ORDER *ord, enum_query_type query_type)
	Print into str the order indicated in ord, using standard print_for_order Used by traditional explain. More...

Public Attributes inherited from Query_term_set_op
mem_root_deque< Query_term * >	m_children
	Tree structure. More...

int64_t	m_last_distinct
	Index of last query expression which has <set-op> DISTINCT on its left. More...

int64_t	m_first_distinct
	Presently only needed by EXCEPT set operator: the index of the first DISTINCT set operand: minimum legal value is 1. More...

bool	m_is_materialized {true}
	true if the result of this set operation is materialized. More...

Protected Member Functions inherited from Query_term_set_op
	Query_term_set_op (MEM_ROOT *mem_root)

void	print (int level, std::ostringstream &buf, const char *type) const
	Common printing minion for set operations. More...

Protected Attributes inherited from Query_term
Query_term_set_op *	m_parent {nullptr}
	Back pointer to the node whose child we are, or nullptr (root term). More...

uint	m_sibling_idx {0}
	If parent is non-null, this holds the index of the current sibling. More...

Query_result *	m_setop_query_result {nullptr}
	The query result for this term. More...

bool	m_owning_operand {false}
	The operand of a n-ary set operation (that owns the common query result) has this set to true. More...

Table_ref *	m_result_table {nullptr}
	Result temporary table for the set operation, if applicable. More...

mem_root_deque< Item * > *	m_fields {nullptr}
	Used only when streaming, i.e. More...

Detailed Description

A <query primary> which is a parenthesized query expression (aka qe) body with order by clause and/or limit/offset clause and the qe body is not a binary set operation (union, except, intersect), but is viewed here as a degenerate set operation; i.e.

a "unary".

/// Example: (SELECT * FROM .. ORDER BY .. LIMIT n) ORDER BY .. LIMIT m
/// Tree:
///      Query_expression
///               | m_query_term
///      Query_term_unary
///      +--------------------+
///      |      m_block ------+---->      Query_block which holds outer
///      |        :           |           ORDER BY and LIMIT
///      |      m_children[0] |
///      +--------|-----------+
///               V
///        Query_block   holds inner SELECT and its ORDER BY/LIMIT
///

One extra Query_term_unary is added for each level of nesting with the top one representing the outermost ORDER BY/LIMIT/OFFSET

Constructor & Destructor Documentation

◆ Query_term_unary()

Query_term_unary::Query_term_unary	(	MEM_ROOT *	mem_root,
		Query_term *	t
	)

inline

Constructor.

Parameters

mem_root	the mem_root to use for allocation
t	the child term

Member Function Documentation

◆ debugPrint()

void Query_term_unary::debugPrint	(	int	level,
		std::ostringstream &	buf
	)		const

overridevirtual

Print the tree rooted at this node to buf.

Call on top level with level==0

Parameters

level	level we are at in tree.
buf	the buffer to format output into

Implements Query_term.

◆ operator_string()

const char * Query_term_unary::operator_string ( ) const

inlineoverridevirtual

Get the node type description.

Returns: descriptive string for each node type.

Implements Query_term.

◆ term_type()

Query_term_type Query_term_unary::term_type ( ) const

inlineoverridevirtual

Get the node tree type.

Returns: the tree node type

Implements Query_term.

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

sql/query_term.h
sql/query_term.cc

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Query_term_unary()

Member Function Documentation

◆ debugPrint()

◆ operator_string()

◆ term_type()