The LEX object currently serves three different purposes: More...

#include <sql_lex.h>

Inheritance diagram for LEX:

Public Types
typedef Prealloced_array< plugin_ref, INITIAL_LEX_PLUGIN_LIST_SIZE >	Plugins_array

Public Types inherited from Query_tables_list
enum	{ START_SROUTINES_HASH_SIZE = 16 }

enum	enum_lock_tables_state { LTS_NOT_LOCKED = 0 , LTS_LOCKED }
	Locking state of tables in this particular statement. More...

enum	enum_binlog_stmt_unsafe { BINLOG_STMT_UNSAFE_LIMIT = 0 , BINLOG_STMT_UNSAFE_SYSTEM_TABLE , BINLOG_STMT_UNSAFE_AUTOINC_COLUMNS , BINLOG_STMT_UNSAFE_UDF , BINLOG_STMT_UNSAFE_SYSTEM_VARIABLE , BINLOG_STMT_UNSAFE_SYSTEM_FUNCTION , BINLOG_STMT_UNSAFE_NONTRANS_AFTER_TRANS , BINLOG_STMT_UNSAFE_MULTIPLE_ENGINES_AND_SELF_LOGGING_ENGINE , BINLOG_STMT_UNSAFE_MIXED_STATEMENT , BINLOG_STMT_UNSAFE_INSERT_IGNORE_SELECT , BINLOG_STMT_UNSAFE_INSERT_SELECT_UPDATE , BINLOG_STMT_UNSAFE_WRITE_AUTOINC_SELECT , BINLOG_STMT_UNSAFE_REPLACE_SELECT , BINLOG_STMT_UNSAFE_CREATE_IGNORE_SELECT , BINLOG_STMT_UNSAFE_CREATE_REPLACE_SELECT , BINLOG_STMT_UNSAFE_CREATE_SELECT_AUTOINC , BINLOG_STMT_UNSAFE_UPDATE_IGNORE , BINLOG_STMT_UNSAFE_INSERT_TWO_KEYS , BINLOG_STMT_UNSAFE_AUTOINC_NOT_FIRST , BINLOG_STMT_UNSAFE_FULLTEXT_PLUGIN , BINLOG_STMT_UNSAFE_SKIP_LOCKED , BINLOG_STMT_UNSAFE_NOWAIT , BINLOG_STMT_UNSAFE_XA , BINLOG_STMT_UNSAFE_DEFAULT_EXPRESSION_IN_SUBSTATEMENT , BINLOG_STMT_UNSAFE_ACL_TABLE_READ_IN_DML_DDL , BINLOG_STMT_UNSAFE_CREATE_SELECT_WITH_GIPK , BINLOG_STMT_UNSAFE_COUNT }
	All types of unsafe statements. More...

enum	enum_stmt_accessed_table { STMT_READS_TRANS_TABLE = 0 , STMT_READS_NON_TRANS_TABLE , STMT_READS_TEMP_TRANS_TABLE , STMT_READS_TEMP_NON_TRANS_TABLE , STMT_WRITES_TRANS_TABLE , STMT_WRITES_NON_TRANS_TABLE , STMT_WRITES_TEMP_TRANS_TABLE , STMT_WRITES_TEMP_NON_TRANS_TABLE , STMT_ACCESS_TABLE_COUNT }

Public Member Functions
Query_block *	current_query_block () const

void	assert_ok_set_current_query_block ()

void	set_current_query_block (Query_block *select)

bool	is_explain () const

bool	using_hypergraph_optimizer () const
	Whether the currently-running query should be (attempted) executed in the hypergraph optimizer. More...

void	set_using_hypergraph_optimizer (bool use_hypergraph)

bool	locate_var_assignment (const Name_string &name)
	Locate an assignment to a user variable with a given name, within statement. More...

void	insert_values_map (Item_field f1, Field f2)

void	destroy_values_map ()

void	clear_values_map ()

bool	has_values_map () const

std::map< Item_field , Field >::iterator	begin_values_map ()

std::map< Item_field , Field >::iterator	end_values_map ()

bool	is_ignore () const

void	set_ignore (bool ignore_param)

void	set_has_udf ()

bool	has_udf () const

ulonglong	statement_options ()
	Gets the options that have been set for this statement. More...

void	add_statement_options (ulonglong options)
	Add options to values of m_statement_options. More...

bool	is_broken () const

void	mark_broken (bool broken=true)
	Certain permanent transformations (like in2exists), if they fail, may leave the LEX in an inconsistent state. More...

bool	check_preparation_invalid (THD *thd)
	Check whether preparation state for prepared statement is invalid. More...

void	cleanup (bool full)

bool	is_exec_started () const

void	set_exec_started ()

void	reset_exec_started ()

bool	is_exec_completed () const
	Check whether the statement has been executed (regardless of completion - successful or in error). More...

void	set_exec_completed ()

sp_pcontext *	get_sp_current_parsing_ctx ()

void	set_sp_current_parsing_ctx (sp_pcontext *ctx)

bool	is_metadata_used () const
	Check if the current statement uses meta-data (uses a table or a stored routine). More...

bool	deny_window_function (Query_block *qb) const
	We have detected the presence of an alias of a window function with a window on query block qb. More...

	LEX ()

virtual	~LEX ()

void	destroy ()
	Destroy contained objects, but not the LEX object itself. More...

void	reset ()
	Reset query context to initial state. More...

Query_block *	new_empty_query_block ()
	Create an empty query block within this LEX object. More...

Query_block *	new_query (Query_block *curr_query_block)
	Create query expression object that contains one query block. More...

Query_block *	new_set_operation_query (Query_block *curr_query_block)
	Create query block and attach it to the current query expression. More...

bool	new_top_level_query ()
	Create top-level query expression and query block. More...

void	new_static_query (Query_expression sel_query_expression, Query_block select)
	Create query expression and query block in existing memory objects. More...

Query_expression *	create_query_expr_and_block (THD thd, Query_block current_query_block, Item where_clause, Item having_clause, enum_parsing_context ctx)
	Create query expression under current_query_block and a query block under the new query expression. More...

bool	is_ps_or_view_context_analysis ()

bool	is_view_context_analysis ()

void	clear_execution ()
	Clear execution state for a statement after it has been prepared or executed, and before it is (re-)executed. More...

void	set_uncacheable (Query_block *curr_query_block, uint8 cause)
	Set the current query as uncacheable. More...

void	set_trg_event_type_for_tables ()
	Set the initial purpose of this Table_ref object in the list of used tables. More...

Table_ref *	unlink_first_table (bool *link_to_local)

void	link_first_table_back (Table_ref *first, bool link_to_local)

void	first_lists_tables_same ()

void	restore_cmd_properties ()

void	restore_properties_for_insert ()

bool	save_cmd_properties (THD *thd)

bool	can_use_merged ()
	check if command can use VIEW with MERGE algorithm (for top VIEWs) More...

bool	can_not_use_merged ()
	Check if command can't use merged views in any part of command. More...

bool	need_correct_ident ()

bool	which_check_option_applicable ()

void	cleanup_after_one_table_open ()

bool	push_context (Name_resolution_context *context)

void	pop_context ()

bool	copy_db_to (char const *p_db, size_t p_db_length) const
	This method should be called only during parsing. More...

bool	copy_db_to (char *p_db, size_t p_db_length) const

Name_resolution_context *	current_context ()

void	reset_n_backup_query_tables_list (Query_tables_list *backup)

void	restore_backup_query_tables_list (Query_tables_list *backup)

bool	table_or_sp_used ()

bool	is_single_level_stmt ()
	check if the statement is a single-level join More...

void	release_plugins ()

bool	accept (Select_lex_visitor *visitor)

bool	set_wild (LEX_STRING)

void	clear_privileges ()

bool	make_sql_cmd (Parse_tree_root *parse_tree)
	Uses parse_tree to instantiate an Sql_cmd object and assigns it to the Lex. More...

Secondary_engine_execution_context *	secondary_engine_execution_context () const
	Gets the secondary engine execution context for this statement. More...

void	set_secondary_engine_execution_context (Secondary_engine_execution_context *context)
	Sets the secondary engine execution context for this statement. More...

bool	is_replication_deprecated_syntax_used ()

void	set_replication_deprecated_syntax_used ()

bool	was_replication_command_executed () const

void	set_was_replication_command_executed ()

bool	set_channel_name (LEX_CSTRING name={})
	Set replication channel name. More...

void	set_rewrite_required ()

void	reset_rewrite_required ()

bool	is_rewrite_required ()

Public Member Functions inherited from Query_tables_list
Query_tables_list &	operator= (Query_tables_list &&)=default

bool	is_query_tables_locked () const

	Query_tables_list ()=default

	~Query_tables_list ()=default

void	reset_query_tables_list (bool init)

void	destroy_query_tables_list ()

void	set_query_tables_list (Query_tables_list *state)

void	add_to_query_tables (Table_ref *table)

bool	requires_prelocking ()

void	mark_as_requiring_prelocking (Table_ref **tables_own_last)

Table_ref *	first_not_own_table ()

void	chop_off_not_own_tables ()

bool	is_stmt_unsafe () const
	Determine if this statement is marked as unsafe. More...

bool	is_stmt_unsafe (enum_binlog_stmt_unsafe unsafe)

void	set_stmt_unsafe (enum_binlog_stmt_unsafe unsafe_type)
	Flag the current (top-level) statement as unsafe. More...

void	set_stmt_unsafe_flags (uint32 flags)
	Set the bits of binlog_stmt_flags determining the type of unsafeness of the current statement. More...

uint32	get_stmt_unsafe_flags () const
	Return a binary combination of all unsafe warnings for the statement. More...

bool	is_stmt_row_injection () const
	Determine if this statement is a row injection. More...

void	set_stmt_row_injection ()
	Flag the statement as a row injection. More...

void	set_stmt_accessed_table (enum_stmt_accessed_table accessed_table)
	Sets the type of table that is about to be accessed while executing a statement. More...

bool	stmt_accessed_table (enum_stmt_accessed_table accessed_table)
	Checks if a type of table is about to be accessed while executing a statement. More...

bool	is_mixed_stmt_unsafe (bool in_multi_stmt_transaction_mode, bool binlog_direct, bool trx_cache_is_not_empty, uint tx_isolation)

bool	uses_stored_routines () const
	true if the parsed tree contains references to stored procedures or functions, false otherwise More...

void	set_using_match ()

bool	get_using_match ()

void	set_stmt_unsafe_with_mixed_mode ()

bool	is_stmt_unsafe_with_mixed_mode () const

Public Attributes
Query_expression *	unit
	Outer-most query expression. More...

Query_block *	query_block
	First query block. More...

Query_block *	all_query_blocks_list
	List of all query blocks. More...

bool	is_explain_analyze = false

LEX_STRING	name

char *	help_arg

char *	to_log

const char *	x509_subject

const char *	x509_issuer

const char *	ssl_cipher

String *	wild

Query_result *	result

LEX_STRING	binlog_stmt_arg
	Argument of the BINLOG event statement. More...

LEX_STRING	ident

LEX_USER *	grant_user

LEX_ALTER	alter_password

enum_alter_user_attribute	alter_user_attribute

LEX_STRING	alter_user_comment_text

LEX_GRANT_AS	grant_as

THD *	thd

Opt_hints_global *	opt_hints_global

Plugins_array	plugins

Table_ref *	insert_table
	Table being inserted into (may be a view) More...

Table_ref *	insert_table_leaf
	Leaf table being inserted into (always a base table) More...

LEX_STRING	create_view_query_block
	SELECT of CREATE VIEW statement. More...

partition_info *	part_info

LEX_USER *	definer

List< LEX_USER >	users_list

List< LEX_COLUMN >	columns

List< LEX_CSTRING >	dynamic_privileges

List< LEX_USER > *	default_roles

ulonglong	bulk_insert_row_cnt

List< Item >	purge_value_list

List< Item >	kill_value_list

List< set_var_base >	var_list

List< Item_func_set_user_var >	set_var_list

List< Item_param >	param_list
	List of placeholders ('?') for parameters of a prepared statement. More...

List< Name_resolution_context >	context_stack

Item_sum *	in_sum_func

udf_func	udf

HA_CHECK_OPT	check_opt

HA_CREATE_INFO *	create_info

KEY_CREATE_INFO	key_create_info

LEX_MASTER_INFO	mi

LEX_SLAVE_CONNECTION	slave_connection

Server_options	server_options

USER_RESOURCES	mqh

LEX_RESET_SLAVE	reset_slave_info

ulong	type

nesting_map	allow_sum_func
	This field is used as a work field during resolving to validate the use of aggregate functions. More...

nesting_map	m_deny_window_func
	Windowing functions are not allowed in HAVING - in contrast to grouped aggregate functions, since windowing in SQL logically follows after all grouping operations. More...

bool	m_subquery_to_derived_is_impossible
	If true: during prepare, we did a subquery transformation (IN-to-EXISTS, SOME/ANY) that doesn't currently work for subquery to a derived table transformation. More...

Sql_cmd *	m_sql_cmd

bool	expr_allows_subquery {true}

uint	reparse_common_table_expr_at
	If currently re-parsing a CTE's definition, this is the offset in bytes of that definition in the original statement which had the WITH clause. More...

bool	reparse_derived_table_condition {false}
	If currently re-parsing a condition which is pushed down to a derived table, this will be set to true. More...

std::vector< uint >	reparse_derived_table_params_at
	If currently re-parsing a condition that is being pushed down to a derived table, this has the positions of all the parameters that are part of that condition in the original statement. More...

enum SSL_type	ssl_type

enum enum_duplicates	duplicates

enum enum_tx_isolation	tx_isolation

enum enum_var_type	option_type

enum_view_create_mode	create_view_mode

my_thread_id	show_profile_query_id
	QUERY ID for SHOW PROFILE. More...

uint	profile_options

uint	grant

uint	grant_tot_col

bool	grant_privilege
	Set to true when GRANT ... GRANT OPTION ... TO ... is used (vs. More...

uint	slave_thd_opt

uint	start_transaction_opt

int	select_number
	Number of query block (by EXPLAIN) More...

uint8	create_view_algorithm

uint8	create_view_check

uint8	context_analysis_only

bool	drop_if_exists

bool	grant_if_exists
	refers to optional IF EXISTS clause in REVOKE sql. More...

bool	ignore_unknown_user
	refers to optional IGNORE UNKNOWN USER clause in REVOKE sql. More...

bool	drop_temporary

bool	autocommit

bool	verbose

bool	no_write_to_binlog

bool	m_extended_show

enum enum_yes_no_unknown tx_chain	tx_release

bool	safe_to_cache_query
	Whether this query will return the same answer every time, given unchanged data. More...

st_parsing_options	parsing_options

Alter_info *	alter_info

LEX_CSTRING	prepared_stmt_name

LEX_STRING	prepared_stmt_code

bool	prepared_stmt_code_is_varref

List< LEX_STRING >	prepared_stmt_params

sp_head *	sphead

sp_name *	spname

bool	sp_lex_in_use

bool	all_privileges

bool	contains_plaintext_password

enum_keep_diagnostics	keep_diagnostics

uint32	next_binlog_file_nr

st_sp_chistics	sp_chistics

Event_parse_data *	event_parse_data

bool	only_view

uint8	create_view_suid

const char *	stmt_definition_begin
	Intended to point to the next word after DEFINER-clause in the following statements: More...

const char *	stmt_definition_end

bool	use_only_table_context
	During name resolution search only in the table list given by Name_resolution_context::first_name_resolution_table and Name_resolution_context::last_name_resolution_table (see Item_field::fix_fields()). More...

bool	is_lex_started

bool	in_update_value_clause
	Set to true while resolving values in ON DUPLICATE KEY UPDATE clause. More...

class Explain_format *	explain_format

ulong	max_execution_time

bool	binlog_need_explicit_defaults_ts

bool	will_contextualize
	Used to inform the parser whether it should contextualize the parse tree. More...

dd::info_schema::Table_statistics	m_IS_table_stats
	IS schema queries read some dynamic table statistics from SE. More...

dd::info_schema::Tablespace_statistics	m_IS_tablespace_stats

Public Attributes inherited from Query_tables_list
enum_sql_command	sql_command
	SQL command for this statement. More...

Table_ref *	query_tables

Table_ref **	query_tables_last

Table_ref **	query_tables_own_last

std::unique_ptr< malloc_unordered_map< std::string, Sroutine_hash_entry * > >	sroutines

SQL_I_List< Sroutine_hash_entry >	sroutines_list

Sroutine_hash_entry **	sroutines_list_own_last

uint	sroutines_list_own_elements

enum_lock_tables_state	lock_tables_state

uint	table_count
	Number of tables which were open by open_tables() and to be locked by lock_tables(). More...

Private Attributes
Query_block *	m_current_query_block

bool	m_using_hypergraph_optimizer {false}

std::map< Item_field , Field > *	insert_update_values_map

bool	m_has_udf {false}
	True if statement references UDF functions. More...

bool	ignore

bool	m_broken
	see mark_broken() More...

bool	m_exec_started
	Set to true when execution has started (after parsing, tables opened and query preparation is complete. More...

bool	m_exec_completed
	Set to true when execution is completed, ie optimization has been done and execution is successful or ended in error. More...

sp_pcontext *	sp_current_parsing_ctx
	Current SP parsing context. More...

ulonglong	m_statement_options {0}
	Statement context for Query_block::make_active_options. More...

Secondary_engine_execution_context *	m_secondary_engine_context {nullptr}
	Context object used by secondary storage engines to store query state during optimization and execution. More...

bool	m_is_replication_deprecated_syntax_used {false}

bool	m_was_replication_command_executed {false}

bool	rewrite_required {false}

Friends
bool	lex_start (THD *thd)
	Call lex_start() before every query that is to be prepared and executed. More...

Additional Inherited Members
Static Public Member Functions inherited from Query_tables_list
static const char *	stmt_accessed_table_string (enum_stmt_accessed_table accessed_table)

Static Public Attributes inherited from Query_tables_list
static const int	BINLOG_STMT_UNSAFE_ALL_FLAGS
	This has all flags from 0 (inclusive) to BINLOG_STMT_FLAG_COUNT (exclusive) set. More...

static const int	binlog_stmt_unsafe_errcode [BINLOG_STMT_UNSAFE_COUNT]
	Maps elements of enum_binlog_stmt_unsafe to error codes. More...

Detailed Description

The LEX object currently serves three different purposes:

It contains some universal properties of an SQL command, such as sql_command, presence of IGNORE in data change statement syntax, and list of tables (query_tables).
It contains some execution state variables, like m_exec_started (set to true when execution is started), plugins (list of plugins used by statement), insert_update_values_map (a map of objects used by certain INSERT statements), etc.
It contains a number of members that should be local to subclasses of Sql_cmd, like purge_value_list (for the PURGE command), kill_value_list (for the KILL command).

The LEX object is strictly a part of class Sql_cmd, for those SQL commands that are represented by an Sql_cmd class. For the remaining SQL commands, it is a standalone object linked to the current THD.

The lifecycle of a LEX object is as follows:

The LEX object is constructed either on the execution mem_root (for regular statements), on a Prepared_statement mem_root (for prepared statements), on an SP mem_root (for stored procedure instructions), or created on the current mem_root for short-lived uses.
Call lex_start() to initialize a LEX object before use. This initializes the execution state part of the object. It also calls LEX::reset() to ensure that all members are properly inited.
Parse and resolve the statement, using the LEX as a work area.
Execute an SQL command: call set_exec_started() when starting to execute (actually when starting to optimize). Typically call is_exec_started() to distinguish between preparation and optimization/execution stages of SQL command execution.
Call clear_execution() when execution is finished. This will clear all execution state associated with the SQL command, it also includes calling LEX::reset_exec_started().

Member Typedef Documentation

◆ Plugins_array

typedef Prealloced_array<plugin_ref, INITIAL_LEX_PLUGIN_LIST_SIZE> LEX::Plugins_array

Constructor & Destructor Documentation

◆ LEX()

LEX::LEX ( )

◆ ~LEX()

LEX::~LEX ( )

virtual

Member Function Documentation

◆ accept()

bool LEX::accept ( Select_lex_visitor * visitor )

◆ add_statement_options()

void LEX::add_statement_options ( ulonglong options )

inline

Add options to values of m_statement_options.

options is an ORed bit set of options defined in query_options.h

Parameters

options Add this set of options to the set already in m_statement_options

◆ assert_ok_set_current_query_block()

void LEX::assert_ok_set_current_query_block ( )

◆ begin_values_map()

std::map< Item_field *, Field * >::iterator LEX::begin_values_map ( )

inline

◆ can_not_use_merged()

bool LEX::can_not_use_merged ( )

Check if command can't use merged views in any part of command.

Temporary table algorithm will be used on all SELECT levels for queries listed here (see also LEX::can_use_merged()).

Returns: true if command cannot use merged view, false otherwise

◆ can_use_merged()

bool LEX::can_use_merged ( )

check if command can use VIEW with MERGE algorithm (for top VIEWs)

Only listed here commands can use merge algorithm in top level Query_block (for subqueries will be used merge algorithm if LEX::can_not_use_merged() is not true).

Returns: true if command can use merged VIEWs, false otherwise

◆ check_preparation_invalid()

bool LEX::check_preparation_invalid ( THD * thd_arg )

Check whether preparation state for prepared statement is invalid.

Preparation state amy become invalid if a repreparation is forced, e.g because of invalid metadata, and that repreparation fails.

Returns: true if preparation state is invalid, false otherwise.

◆ cleanup()

void LEX::cleanup ( bool full )

inline

◆ cleanup_after_one_table_open()

void LEX::cleanup_after_one_table_open ( )

◆ clear_execution()

void LEX::clear_execution ( )

Clear execution state for a statement after it has been prepared or executed, and before it is (re-)executed.

◆ clear_privileges()

void LEX::clear_privileges ( )

◆ clear_values_map()

void LEX::clear_values_map ( )

inline

◆ copy_db_to() [1/2]

bool LEX::copy_db_to	(	char **	p_db,
		size_t *	p_db_length
	)		const

inline

◆ copy_db_to() [2/2]

bool LEX::copy_db_to	(	char const **	p_db,
		size_t *	p_db_length
	)		const

This method should be called only during parsing.

It is aware of compound statements (stored routine bodies) and will initialize the destination with the default database of the stored routine, rather than the default database of the connection it is parsed in. E.g. if one has no current database selected, or current database set to 'bar' and then issues:

CREATE PROCEDURE foo.p1() BEGIN SELECT * FROM t1 END//

t1 is meant to refer to foo.t1, not to bar.t1.

This method is needed to support this rule.

Returns: true in case of error (parsing should be aborted, false in case of success

◆ create_query_expr_and_block()

Query_expression * LEX::create_query_expr_and_block	(	THD *	thd,
		Query_block *	current_query_block,
		Item *	where_clause,
		Item *	having_clause,
		enum_parsing_context	ctx
	)

Create query expression under current_query_block and a query block under the new query expression.

The new query expression is linked in under current_query_block. The new query block is linked in under the new query expression.

Parameters

thd	current session context
current_query_block	the root under which we create the new expression and block
where_clause	any where clause for the block
having_clause	any having clause for the block
ctx	the parsing context

Returns: the new query expression, or nullptr on error.

◆ current_context()

Name_resolution_context * LEX::current_context ( )

inline

◆ current_query_block()

Query_block * LEX::current_query_block ( ) const

inline

◆ deny_window_function()

bool LEX::deny_window_function ( Query_block * qb ) const

inline

We have detected the presence of an alias of a window function with a window on query block qb.

Check if the reference is illegal at this point during resolution.

Parameters

qb	The query block of the window function

Returns: true if window function is referenced from another query block than its window, or if window functions are disallowed at the current point during prepare, cf. also documentation of m_deny_window_func.

◆ destroy()

void LEX::destroy ( )

inline

Destroy contained objects, but not the LEX object itself.

◆ destroy_values_map()

void LEX::destroy_values_map ( )

inline

◆ end_values_map()

std::map< Item_field *, Field * >::iterator LEX::end_values_map ( )

inline

◆ first_lists_tables_same()

void LEX::first_lists_tables_same ( )

◆ get_sp_current_parsing_ctx()

sp_pcontext * LEX::get_sp_current_parsing_ctx ( )

inline

◆ has_udf()

bool LEX::has_udf ( ) const

inline

◆ has_values_map()

bool LEX::has_values_map ( ) const

inline

◆ insert_values_map()

void LEX::insert_values_map	(	Item_field *	f1,
		Field *	f2
	)

inline

◆ is_broken()

bool LEX::is_broken ( ) const

inline

◆ is_exec_completed()

bool LEX::is_exec_completed ( ) const

inline

Check whether the statement has been executed (regardless of completion - successful or in error).

Check this instead of Query_expression::is_executed() to determine the state of a complete statement.

◆ is_exec_started()

bool LEX::is_exec_started ( ) const

inline

◆ is_explain()

bool LEX::is_explain ( ) const

inline

Returns: true if this is an EXPLAIN statement

◆ is_ignore()

bool LEX::is_ignore ( ) const

inline

◆ is_metadata_used()

bool LEX::is_metadata_used ( ) const

inline

Check if the current statement uses meta-data (uses a table or a stored routine).

◆ is_ps_or_view_context_analysis()

bool LEX::is_ps_or_view_context_analysis ( )

inline

◆ is_replication_deprecated_syntax_used()

bool LEX::is_replication_deprecated_syntax_used ( )

inline

◆ is_rewrite_required()

bool LEX::is_rewrite_required ( )

inline

◆ is_single_level_stmt()

bool LEX::is_single_level_stmt ( )

inline

check if the statement is a single-level join

Returns: result of the check

Return values

true	The statement doesn't contain subqueries, unions and stored procedure calls.
false	There are subqueries, UNIONs or stored procedure calls.

◆ is_view_context_analysis()

bool LEX::is_view_context_analysis ( )

inline

◆ link_first_table_back()

void LEX::link_first_table_back	(	Table_ref *	first,
		bool	link_to_local
	)

◆ locate_var_assignment()

bool LEX::locate_var_assignment ( const Name_string & name )

Locate an assignment to a user variable with a given name, within statement.

Parameters

name	Name of variable to search for

Returns: true if variable is assigned to, false otherwise.

◆ make_sql_cmd()

bool LEX::make_sql_cmd ( Parse_tree_root * parse_tree )

Uses parse_tree to instantiate an Sql_cmd object and assigns it to the Lex.

Parameters

parse_tree The parse tree.

Returns: false on success, true on error.

◆ mark_broken()

void LEX::mark_broken ( bool broken = true )

inline

Certain permanent transformations (like in2exists), if they fail, may leave the LEX in an inconsistent state.

They should call the following function, so that this LEX is not reused by another execution.

◆ need_correct_ident()

bool LEX::need_correct_ident ( )

◆ new_empty_query_block()

Query_block * LEX::new_empty_query_block ( )

Create an empty query block within this LEX object.

◆ new_query()

Query_block * LEX::new_query ( Query_block * curr_query_block )

Create query expression object that contains one query block.

Create new query_block_query_expression and query_block objects for a query block, which can be either a top-level query or a subquery.

For the second and subsequent query block of a UNION query, use LEX::new_set_operation_query() instead. Set the new query_block as the current query_block of the LEX object.

Parameters

curr_query_block current query block, NULL if an outer-most query block should be created.

Returns: new query specification if successful, NULL if error

◆ new_set_operation_query()

Query_block * LEX::new_set_operation_query ( Query_block * curr_query_block )

Create query block and attach it to the current query expression.

Create new query_block object for all branches of a UNION, EXCEPT or INTERSECT except the left-most one.

Set the new query_block as the current query_block of the LEX object.

Parameters

curr_query_block current query specification

Returns: new query specification if successful, NULL if an error occurred.

◆ new_static_query()

void LEX::new_static_query	(	Query_expression *	sel_query_expression,
		Query_block *	select
	)

Create query expression and query block in existing memory objects.

Initialize a LEX object, a query expression object (query_block_query_expression) and a query block object (query_block).

All objects are passed as pointers so they can be stack-allocated. The purpose of this structure is for short-lived procedures that need a LEX and a query block object.

Do not extend the struct with more query objects after creation.

The struct can be abandoned after use, no cleanup is needed.

Parameters

sel_query_expression	Pointer to the query expression object
select	Pointer to the query block object

◆ new_top_level_query()

bool LEX::new_top_level_query ( )

Create top-level query expression and query block.

Given a LEX object, create a query expression object (query_block_query_expression) and a query block object (query_block).

Returns: false if successful, true if error

◆ pop_context()

void LEX::pop_context ( )

inline

◆ push_context()

bool LEX::push_context ( Name_resolution_context * context )

inline

◆ release_plugins()

void LEX::release_plugins ( )

◆ reset()

void LEX::reset ( void )

Reset query context to initial state.

Reset a LEX object so that it is ready for a new query preparation and execution.

Pointers to query expression and query block objects are set to NULL. This is correct, as they point into a mem_root that has been recycled.

◆ reset_exec_started()

void LEX::reset_exec_started ( )

inline

◆ reset_n_backup_query_tables_list()

void LEX::reset_n_backup_query_tables_list ( Query_tables_list * backup )

◆ reset_rewrite_required()

void LEX::reset_rewrite_required ( )

inline

◆ restore_backup_query_tables_list()

void LEX::restore_backup_query_tables_list ( Query_tables_list * backup )

◆ restore_cmd_properties()

void LEX::restore_cmd_properties ( )

inline

◆ restore_properties_for_insert()

void LEX::restore_properties_for_insert ( )

inline

◆ save_cmd_properties()

bool LEX::save_cmd_properties ( THD * thd )

inline

◆ secondary_engine_execution_context()

Secondary_engine_execution_context * LEX::secondary_engine_execution_context ( ) const

inline

Gets the secondary engine execution context for this statement.

◆ set_channel_name()

bool LEX::set_channel_name ( LEX_CSTRING name = {} )

Set replication channel name.

Parameters

name	If `name` is null string then reset channel name to default. Otherwise set it to `name`.

Returns: false if success, true if error (OOM).

◆ set_current_query_block()

void LEX::set_current_query_block ( Query_block * select )

inline

◆ set_exec_completed()

void LEX::set_exec_completed ( )

inline

◆ set_exec_started()

void LEX::set_exec_started ( )

inline

◆ set_has_udf()

void LEX::set_has_udf ( )

inline

◆ set_ignore()

void LEX::set_ignore ( bool ignore_param )

inline

◆ set_replication_deprecated_syntax_used()

void LEX::set_replication_deprecated_syntax_used ( )

inline

◆ set_rewrite_required()

void LEX::set_rewrite_required ( )

inline

◆ set_secondary_engine_execution_context()

void LEX::set_secondary_engine_execution_context ( Secondary_engine_execution_context * context )

Sets the secondary engine execution context for this statement.

The old context object is destroyed, if there is one. Can be set to nullptr to destroy the old context object and clear the pointer.

The supplied context object should be allocated on the execution MEM_ROOT, so that its memory doesn't have to be manually freed after query execution.

◆ set_sp_current_parsing_ctx()

void LEX::set_sp_current_parsing_ctx ( sp_pcontext * ctx )

inline

◆ set_trg_event_type_for_tables()

void LEX::set_trg_event_type_for_tables ( )

Set the initial purpose of this Table_ref object in the list of used tables.

We need to track this information on table-by-table basis, since when this table becomes an element of the pre-locked list, it's impossible to identify which SQL sub-statement it has been originally used in.

E.g.:

User request: SELECT * FROM t1 WHERE f1(); FUNCTION f1(): DELETE FROM t2; RETURN 1; BEFORE DELETE trigger on t2: INSERT INTO t3 VALUES (old.a);

For this user request, the pre-locked list will contain t1, t2, t3 table elements, each needed for different DML.

The trigger event map is updated to reflect INSERT, UPDATE, DELETE, REPLACE, LOAD DATA, CREATE TABLE .. SELECT, CREATE TABLE .. REPLACE SELECT statements, and additionally ON DUPLICATE KEY UPDATE clause.

◆ set_uncacheable()

void LEX::set_uncacheable	(	Query_block *	curr_query_block,
		uint8	cause
	)

inline

Set the current query as uncacheable.

Parameters

curr_query_block	Current select query block
cause	Why this query is uncacheable.

All query blocks representing subqueries, from the current one up to the outer-most one, but excluding the main query block, are also set as uncacheable.

◆ set_using_hypergraph_optimizer()

void LEX::set_using_hypergraph_optimizer ( bool use_hypergraph )

inline

◆ set_was_replication_command_executed()

void LEX::set_was_replication_command_executed ( )

inline

◆ set_wild()

bool LEX::set_wild ( LEX_STRING w )

◆ statement_options()

ulonglong LEX::statement_options ( )

inline

Gets the options that have been set for this statement.

The options are propagated to the Query_block objects and should usually be read with Query_block::active_options().

Returns: a bit set of options set for this statement

◆ table_or_sp_used()

bool LEX::table_or_sp_used ( )

◆ unlink_first_table()

Table_ref * LEX::unlink_first_table ( bool * link_to_local )

◆ using_hypergraph_optimizer()

bool LEX::using_hypergraph_optimizer ( ) const

inline

Whether the currently-running query should be (attempted) executed in the hypergraph optimizer.

This will not change after the query is done parsing, so you can use it in any query phase to e.g. figure out whether to inhibit some transformation that the hypergraph optimizer does not properly understand yet.

◆ was_replication_command_executed()

bool LEX::was_replication_command_executed ( ) const

inline

◆ which_check_option_applicable()

bool LEX::which_check_option_applicable ( )

inline

Friends And Related Function Documentation

◆ lex_start

bool lex_start ( THD * thd )

friend

Call lex_start() before every query that is to be prepared and executed.

Because of this, it's critical not to do too many things here. (We already do too much)

The function creates a query_block and a query_block_query_expression object. These objects should rather be created by the parser bottom-up.

Member Data Documentation

◆ all_privileges

bool LEX::all_privileges

◆ all_query_blocks_list

Query_block* LEX::all_query_blocks_list

List of all query blocks.

◆ allow_sum_func

nesting_map LEX::allow_sum_func

This field is used as a work field during resolving to validate the use of aggregate functions.

For example in a query SELECT ... FROM ...WHERE MIN(i) == 1 GROUP BY ... HAVING MIN(i) > 2 MIN(i) in the WHERE clause is not allowed since only non-aggregated data is present, whereas MIN(i) in the HAVING clause is allowed because HAVING operates on the output of a grouping operation. Each query block is assigned a nesting level. This field is a bit field that contains the value one in the position of that nesting level if aggregate functions are allowed for that query block.

◆ alter_info

Alter_info* LEX::alter_info

◆ alter_password

LEX_ALTER LEX::alter_password

◆ alter_user_attribute

enum_alter_user_attribute LEX::alter_user_attribute

◆ alter_user_comment_text

LEX_STRING LEX::alter_user_comment_text

◆ autocommit

bool LEX::autocommit

◆ binlog_need_explicit_defaults_ts

bool LEX::binlog_need_explicit_defaults_ts

◆ binlog_stmt_arg

LEX_STRING LEX::binlog_stmt_arg

Initial value:

= {

nullptr, 0}

Argument of the BINLOG event statement.

◆ bulk_insert_row_cnt

ulonglong LEX::bulk_insert_row_cnt

◆ check_opt

HA_CHECK_OPT LEX::check_opt

◆ columns

List<LEX_COLUMN> LEX::columns

◆ contains_plaintext_password

bool LEX::contains_plaintext_password

◆ context_analysis_only

uint8 LEX::context_analysis_only

◆ context_stack

List<Name_resolution_context> LEX::context_stack

◆ create_info

HA_CREATE_INFO* LEX::create_info

◆ create_view_algorithm

uint8 LEX::create_view_algorithm

◆ create_view_check

uint8 LEX::create_view_check

◆ create_view_mode

enum_view_create_mode LEX::create_view_mode

◆ create_view_query_block

LEX_STRING LEX::create_view_query_block

SELECT of CREATE VIEW statement.

◆ create_view_suid

uint8 LEX::create_view_suid

◆ default_roles

List<LEX_USER>* LEX::default_roles

◆ definer

LEX_USER* LEX::definer

◆ drop_if_exists

bool LEX::drop_if_exists

◆ drop_temporary

bool LEX::drop_temporary

◆ duplicates

enum enum_duplicates LEX::duplicates

◆ dynamic_privileges

List<LEX_CSTRING> LEX::dynamic_privileges

◆ event_parse_data

Event_parse_data* LEX::event_parse_data

◆ explain_format

class Explain_format* LEX::explain_format

◆ expr_allows_subquery

bool LEX::expr_allows_subquery {true}

◆ grant

uint LEX::grant

◆ grant_as

LEX_GRANT_AS LEX::grant_as

◆ grant_if_exists

bool LEX::grant_if_exists

refers to optional IF EXISTS clause in REVOKE sql.

This flag when set to true will report warnings in case privilege being granted is not granted to given user/role. When set to false error is reported.

◆ grant_privilege

bool LEX::grant_privilege

Set to true when GRANT ... GRANT OPTION ... TO ... is used (vs.

GRANT ... WITH GRANT OPTION). The flag is used by mysql_grant to grant GRANT OPTION (GRANT_ACL) to all dynamic privileges.

◆ grant_tot_col

uint LEX::grant_tot_col

◆ grant_user

LEX_USER* LEX::grant_user

◆ help_arg

char* LEX::help_arg

◆ ident

LEX_STRING LEX::ident

◆ ignore

bool LEX::ignore

private

◆ ignore_unknown_user

bool LEX::ignore_unknown_user

refers to optional IGNORE UNKNOWN USER clause in REVOKE sql.

This flag when set to true will report warnings in case target user/role for which privilege being granted does not exists. When set to false error is reported.

◆ in_sum_func

Item_sum* LEX::in_sum_func

◆ in_update_value_clause

bool LEX::in_update_value_clause

Set to true while resolving values in ON DUPLICATE KEY UPDATE clause.

◆ insert_table

Table_ref* LEX::insert_table

Table being inserted into (may be a view)

◆ insert_table_leaf

Table_ref* LEX::insert_table_leaf

Leaf table being inserted into (always a base table)

◆ insert_update_values_map

std::map<Item_field *, Field *>* LEX::insert_update_values_map

private

◆ is_explain_analyze

bool LEX::is_explain_analyze = false

◆ is_lex_started

bool LEX::is_lex_started

◆ keep_diagnostics

enum_keep_diagnostics LEX::keep_diagnostics

◆ key_create_info

KEY_CREATE_INFO LEX::key_create_info

◆ kill_value_list

List<Item> LEX::kill_value_list

◆ m_broken

bool LEX::m_broken

private

see mark_broken()

◆ m_current_query_block

Query_block* LEX::m_current_query_block

private

◆ m_deny_window_func

nesting_map LEX::m_deny_window_func

Windowing functions are not allowed in HAVING - in contrast to grouped aggregate functions, since windowing in SQL logically follows after all grouping operations.

Nor are they allowed inside grouped aggregate function arguments. One bit per query block, as also allow_sum_func. For ORDER BY and QUALIFY predicates, window functions are allowed unless they are contained in arguments of a grouped aggregate function. Nor are references to outer window functions (via alias) allowed in subqueries, but that is checked separately.

◆ m_exec_completed

bool LEX::m_exec_completed

private

Set to true when execution is completed, ie optimization has been done and execution is successful or ended in error.

◆ m_exec_started

bool LEX::m_exec_started

private

Set to true when execution has started (after parsing, tables opened and query preparation is complete.

Used to track arena state for SPs).

◆ m_extended_show

bool LEX::m_extended_show

◆ m_has_udf

bool LEX::m_has_udf {false}

private

True if statement references UDF functions.

◆ m_is_replication_deprecated_syntax_used

bool LEX::m_is_replication_deprecated_syntax_used {false}

private

◆ m_IS_table_stats

dd::info_schema::Table_statistics LEX::m_IS_table_stats

IS schema queries read some dynamic table statistics from SE.

These statistics are cached, to avoid opening of table more than once while preparing a single output record buffer.

◆ m_IS_tablespace_stats

dd::info_schema::Tablespace_statistics LEX::m_IS_tablespace_stats

◆ m_secondary_engine_context

Secondary_engine_execution_context* LEX::m_secondary_engine_context {nullptr}

private

Context object used by secondary storage engines to store query state during optimization and execution.

◆ m_sql_cmd

Sql_cmd* LEX::m_sql_cmd

◆ m_statement_options

ulonglong LEX::m_statement_options {0}

private

Statement context for Query_block::make_active_options.

◆ m_subquery_to_derived_is_impossible

bool LEX::m_subquery_to_derived_is_impossible

If true: during prepare, we did a subquery transformation (IN-to-EXISTS, SOME/ANY) that doesn't currently work for subquery to a derived table transformation.

◆ m_using_hypergraph_optimizer

bool LEX::m_using_hypergraph_optimizer {false}

private

◆ m_was_replication_command_executed

bool LEX::m_was_replication_command_executed {false}

private

◆ max_execution_time

ulong LEX::max_execution_time

◆ mi

LEX_MASTER_INFO LEX::mi

◆ mqh

USER_RESOURCES LEX::mqh

◆ name

LEX_STRING LEX::name

◆ next_binlog_file_nr

uint32 LEX::next_binlog_file_nr

◆ no_write_to_binlog

bool LEX::no_write_to_binlog

◆ only_view

bool LEX::only_view

◆ opt_hints_global

Opt_hints_global* LEX::opt_hints_global

◆ option_type

enum enum_var_type LEX::option_type

◆ param_list

List<Item_param> LEX::param_list

List of placeholders ('?') for parameters of a prepared statement.

Because we append to this list during parsing, it is naturally sorted by position of the '?' in the query string. The code which fills placeholders with user-supplied values, and the code which writes a query for statement-based logging, rely on this order. This list contains only real placeholders, not the clones which originate in a re-parsed CTE definition.

◆ parsing_options

st_parsing_options LEX::parsing_options

◆ part_info

partition_info* LEX::part_info

◆ plugins

Plugins_array LEX::plugins

◆ prepared_stmt_code

LEX_STRING LEX::prepared_stmt_code

◆ prepared_stmt_code_is_varref

bool LEX::prepared_stmt_code_is_varref

◆ prepared_stmt_name

LEX_CSTRING LEX::prepared_stmt_name

◆ prepared_stmt_params

List<LEX_STRING> LEX::prepared_stmt_params

◆ profile_options

uint LEX::profile_options

◆ purge_value_list

List<Item> LEX::purge_value_list

◆ query_block

Query_block* LEX::query_block

First query block.

◆ reparse_common_table_expr_at

uint LEX::reparse_common_table_expr_at

If currently re-parsing a CTE's definition, this is the offset in bytes of that definition in the original statement which had the WITH clause.

Otherwise this is 0.

◆ reparse_derived_table_condition

bool LEX::reparse_derived_table_condition {false}

If currently re-parsing a condition which is pushed down to a derived table, this will be set to true.

◆ reparse_derived_table_params_at

std::vector<uint> LEX::reparse_derived_table_params_at

If currently re-parsing a condition that is being pushed down to a derived table, this has the positions of all the parameters that are part of that condition in the original statement.

Otherwise it is empty.

◆ reset_slave_info

LEX_RESET_SLAVE LEX::reset_slave_info

◆ result

Query_result* LEX::result

◆ rewrite_required

bool LEX::rewrite_required {false}

private

◆ safe_to_cache_query

bool LEX::safe_to_cache_query

Whether this query will return the same answer every time, given unchanged data.

Used to be for the query cache, but is now used to find out if an expression is usable for partitioning.

◆ select_number

int LEX::select_number

Number of query block (by EXPLAIN)

◆ server_options

Server_options LEX::server_options

◆ set_var_list

List<Item_func_set_user_var> LEX::set_var_list

◆ show_profile_query_id

my_thread_id LEX::show_profile_query_id

QUERY ID for SHOW PROFILE.

◆ slave_connection

LEX_SLAVE_CONNECTION LEX::slave_connection

◆ slave_thd_opt

uint LEX::slave_thd_opt

◆ sp_chistics

st_sp_chistics LEX::sp_chistics

◆ sp_current_parsing_ctx

sp_pcontext* LEX::sp_current_parsing_ctx

private

Current SP parsing context.

See also: also sp_head::m_root_parsing_ctx.

◆ sp_lex_in_use

bool LEX::sp_lex_in_use

◆ sphead

sp_head* LEX::sphead

◆ spname

sp_name* LEX::spname

◆ ssl_cipher

const char * LEX::ssl_cipher

◆ ssl_type

enum SSL_type LEX::ssl_type

◆ start_transaction_opt

uint LEX::start_transaction_opt

◆ stmt_definition_begin

const char* LEX::stmt_definition_begin

Intended to point to the next word after DEFINER-clause in the following statements:

CREATE TRIGGER (points to "TRIGGER");
CREATE PROCEDURE (points to "PROCEDURE");
CREATE FUNCTION (points to "FUNCTION" or "AGGREGATE");
CREATE EVENT (points to "EVENT")

This pointer is required to add possibly omitted DEFINER-clause to the DDL-statement before dumping it to the binlog.

◆ stmt_definition_end

const char* LEX::stmt_definition_end

◆ thd

THD* LEX::thd

◆ to_log

char* LEX::to_log

◆ tx_isolation

enum enum_tx_isolation LEX::tx_isolation

◆ tx_release

enum enum_yes_no_unknown tx_chain LEX::tx_release

◆ type

ulong LEX::type

◆ udf

udf_func LEX::udf

◆ unit

Query_expression* LEX::unit

Outer-most query expression.

◆ use_only_table_context

bool LEX::use_only_table_context

During name resolution search only in the table list given by Name_resolution_context::first_name_resolution_table and Name_resolution_context::last_name_resolution_table (see Item_field::fix_fields()).

◆ users_list

List<LEX_USER> LEX::users_list

◆ var_list

List<set_var_base> LEX::var_list

◆ verbose

bool LEX::verbose

◆ wild

String* LEX::wild

◆ will_contextualize

bool LEX::will_contextualize

Used to inform the parser whether it should contextualize the parse tree.

When we get a pure parser this will not be needed.

◆ x509_issuer

const char * LEX::x509_issuer

◆ x509_subject

const char* LEX::x509_subject

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

sql/sql_lex.h
sql/sql_lex.cc

Public Types

Public Member Functions

Public Attributes

Private Attributes

Friends

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ Plugins_array

Constructor & Destructor Documentation

◆ LEX()

◆ ~LEX()

Member Function Documentation

◆ accept()

◆ add_statement_options()

◆ assert_ok_set_current_query_block()

◆ begin_values_map()

◆ can_not_use_merged()

◆ can_use_merged()

◆ check_preparation_invalid()

◆ cleanup()

◆ cleanup_after_one_table_open()

◆ clear_execution()

◆ clear_privileges()

◆ clear_values_map()

◆ copy_db_to() [1/2]

◆ copy_db_to() [2/2]

◆ create_query_expr_and_block()

◆ current_context()

◆ current_query_block()

◆ deny_window_function()

◆ destroy()

◆ destroy_values_map()

◆ end_values_map()

◆ first_lists_tables_same()

◆ get_sp_current_parsing_ctx()

◆ has_udf()

◆ has_values_map()

◆ insert_values_map()

◆ is_broken()

◆ is_exec_completed()

◆ is_exec_started()

◆ is_explain()

◆ is_ignore()

◆ is_metadata_used()

◆ is_ps_or_view_context_analysis()

◆ is_replication_deprecated_syntax_used()

◆ is_rewrite_required()

◆ is_single_level_stmt()

◆ is_view_context_analysis()

◆ link_first_table_back()

◆ locate_var_assignment()

◆ make_sql_cmd()

◆ mark_broken()

◆ need_correct_ident()

◆ new_empty_query_block()

◆ new_query()

◆ new_set_operation_query()

◆ new_static_query()

◆ new_top_level_query()

◆ pop_context()

◆ push_context()

◆ release_plugins()

◆ reset()

◆ reset_exec_started()

◆ reset_n_backup_query_tables_list()

◆ reset_rewrite_required()

◆ restore_backup_query_tables_list()

◆ restore_cmd_properties()

◆ restore_properties_for_insert()

◆ save_cmd_properties()

◆ secondary_engine_execution_context()

◆ set_channel_name()

◆ set_current_query_block()

◆ set_exec_completed()

◆ set_exec_started()

◆ set_has_udf()

◆ set_ignore()

◆ set_replication_deprecated_syntax_used()

◆ set_rewrite_required()