Table_triggers_list Class Reference

#include <sql_trigger.h>

Inheritance diagram for Table_triggers_list:

List of all members.

Public Member Functions
	Table_triggers_list (TABLE *table_arg)
bool	create_trigger (THD *thd, TABLE_LIST *table, String *stmt_query)
bool	drop_trigger (THD *thd, TABLE_LIST *table, String *stmt_query)
bool	process_triggers (THD *thd, trg_event_type event, trg_action_time_type time_type, bool old_row_is_record1)
bool	get_trigger_info (THD *thd, trg_event_type event, trg_action_time_type time_type, LEX_STRING *trigger_name, LEX_STRING *trigger_stmt, sql_mode_t *sql_mode, LEX_STRING *definer, LEX_STRING *client_cs_name, LEX_STRING *connection_cl_name, LEX_STRING *db_cl_name)
void	get_trigger_info (THD *thd, int trigger_idx, LEX_STRING *trigger_name, sql_mode_t *sql_mode, LEX_STRING *sql_original_stmt, LEX_STRING *client_cs_name, LEX_STRING *connection_cl_name, LEX_STRING *db_cl_name)
int	find_trigger_by_name (const LEX_STRING *trigger_name)
bool	has_triggers (trg_event_type event_type, trg_action_time_type action_time)
bool	has_delete_triggers ()
bool	has_update_triggers ()
void	set_table (TABLE *new_table)
void	mark_fields_used (trg_event_type event)
void	set_parse_error_message (char *error_message)
bool	add_tables_and_routines_for_triggers (THD *thd, Query_tables_list *prelocking_ctx, TABLE_LIST *table_list)
bool	is_fields_updated_in_trigger (MY_BITMAP *used_fields, trg_event_type event_type, trg_action_time_type action_time)
Static Public Member Functions
static bool	check_n_load (THD *thd, const char *db, const char *table_name, TABLE *table, bool names_only)
static bool	drop_all_triggers (THD *thd, char *db, char *table_name)
static bool	change_table_name (THD *thd, const char *db, const char *old_alias, const char *old_table, const char *new_db, const char *new_table)
Public Attributes
TABLE *	trigger_table
GRANT_INFO	subject_table_grants [TRG_EVENT_MAX][TRG_ACTION_MAX]
List< LEX_STRING >	definitions_list
List< ulonglong >	definition_modes_list
List< LEX_STRING >	definers_list
List< LEX_STRING >	client_cs_names
List< LEX_STRING >	connection_cl_names
List< LEX_STRING >	db_cl_names
Friends
class	Item_trigger_field

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Detailed Description

This class holds all information about triggers of table.

QQ: Will it be merged into TABLE in the future ?

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Member Function Documentation

bool Table_triggers_list::add_tables_and_routines_for_triggers	(	THD *	thd,
		Query_tables_list *	prelocking_ctx,
		TABLE_LIST *	table_list
	)

Add triggers for table to the set of routines used by statement. Add tables used by them to statement table list. Do the same for routines used by triggers.

Parameters:

thd	Thread context.
prelocking_ctx	Prelocking context of the statement.
table_list	Table list element for table with trigger.

Return values:

FALSE	Success.
TRUE	Failure.

bool Table_triggers_list::change_table_name	(	THD *	thd,
		const char *	db,
		const char *	old_alias,
		const char *	old_table,
		const char *	new_db,
		const char *	new_table
	)		[static]

Update .TRG and .TRN files after renaming triggers' subject table.

Parameters:

[in,out]	thd	Thread context
[in]	db	Old database of subject table
[in]	old_alias	Old alias of subject table
[in]	old_table	Old name of subject table
[in]	new_db	New database for subject table
[in]	new_table	New name of subject table

Note:

This method tries to leave trigger related files in consistent state, i.e. it either will complete successfully, or will fail leaving files in their initial state. Also this method assumes that subject table is not renamed to itself. This method needs to be called under an exclusive table metadata lock.

Return values:

FALSE	Success
TRUE	Error

bool Table_triggers_list::check_n_load	(	THD *	thd,
		const char *	db,
		const char *	table_name,
		TABLE *	table,
		bool	names_only
	)		[static]

Check whenever .TRG file for table exist and load all triggers it contains.

Parameters:

thd	current thread context
db	table's database name
table_name	table's name
table	pointer to table object
names_only	stop after loading trigger names

Todo:

A lot of things to do here e.g. how about other funcs and being more paranoical ?

Todo:

This could be avoided if there is no triggers for UPDATE and DELETE.

Return values:

False	success
True	error

bool Table_triggers_list::create_trigger	(	THD *	thd,
		TABLE_LIST *	tables,
		String *	stmt_query
	)

Create trigger for table.

Parameters:

	thd	current thread context (including trigger definition in LEX)
	tables	table list containing one open table for which the trigger is created.
[out]	stmt_query	after successful return, this string contains well-formed statement for creation this trigger.

Note:

• Assumes that trigger name is fully qualified.
• NULL-string means the following LEX_STRING instance: { str = 0; length = 0 }.
• In other words, definer_user and definer_host should contain simultaneously NULL-strings (non-SUID/old trigger) or valid strings (SUID/new trigger).

Return values:

False	success
True	error

bool Table_triggers_list::drop_all_triggers	(	THD *	thd,
		char *	db,
		char *	name
	)		[static]

Drop all triggers for table.

Parameters:

thd	current thread context
db	schema for table
name	name for table

Return values:

False	success
True	error

bool Table_triggers_list::drop_trigger	(	THD *	thd,
		TABLE_LIST *	tables,
		String *	stmt_query
	)

Drop trigger for table.

Parameters:

	thd	current thread context (including trigger definition in LEX)
	tables	table list containing one open table for which trigger is dropped.
[out]	stmt_query	after successful return, this string contains well-formed statement for creation this trigger.

Todo:

Probably instead of removing .TRG file we should move to archive directory but this should be done as part of parse_file.cc functionality (because we will need it elsewhere).

Return values:

False	success
True	error

bool Table_triggers_list::get_trigger_info	(	THD *	thd,
		trg_event_type	event,
		trg_action_time_type	time_type,
		LEX_STRING *	trigger_name,
		LEX_STRING *	trigger_stmt,
		sql_mode_t *	sql_mode,
		LEX_STRING *	definer,
		LEX_STRING *	client_cs_name,
		LEX_STRING *	connection_cl_name,
		LEX_STRING *	db_cl_name
	)

Obtains and returns trigger metadata.

Parameters:

thd	current thread context
event	trigger event type
time_type	trigger action time
trigger_name	returns name of trigger
trigger_stmt	returns statement of trigger
sql_mode	returns sql_mode of trigger
definer	returns definer/creator of trigger. The caller is responsible to allocate enough space for storing definer information.

Return values:

False	success
True	error

bool Table_triggers_list::is_fields_updated_in_trigger	(	MY_BITMAP *	used_fields,
		trg_event_type	event_type,
		trg_action_time_type	action_time
	)

Check if any of the marked fields are used in the trigger.

Parameters:

used_fields	Bitmap over fields to check
event_type	Type of event triggers for which we are going to inspect
action_time	Type of trigger action time we are going to inspect

void Table_triggers_list::mark_fields_used

(

trg_event_type

event

)

Mark fields of subject table which we read/set in its triggers as such.

This method marks fields of subject table which are read/set in its triggers as such (by properly updating TABLE::read_set/write_set) and thus informs handler that values for these fields should be retrieved/stored during execution of statement.

Parameters:

event

Type of event triggers for which we are going to inspect

bool Table_triggers_list::process_triggers	(	THD *	thd,
		trg_event_type	event,
		trg_action_time_type	time_type,
		bool	old_row_is_record1
	)

Execute trigger for given (event, time) pair.

The operation executes trigger for the specified event (insert, update, delete) and time (after, before) if it is set.

Parameters:

thd
event
time_type
old_row_is_record1

Returns:

Error status.

Return values:

FALSE	on success.
TRUE	on error.

void Table_triggers_list::set_parse_error_message

(

char *

error_message

)

Signals to the Table_triggers_list that a parse error has occured when reading a trigger from file. This makes the Table_triggers_list enter an error state flagged by m_has_unparseable_trigger == true. The error message will be used whenever a statement invoking or manipulating triggers is issued against the Table_triggers_list's table.

Parameters:

error_message

The error message thrown by the parser.

void Table_triggers_list::set_table

(

TABLE *

new_table

)

Adjust Table_triggers_list with new TABLE pointer.

Parameters:

new_table

new pointer to TABLE instance

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Member Data Documentation

List<ulonglong> Table_triggers_list::definition_modes_list

List of sql modes for triggers

List<LEX_STRING> Table_triggers_list::definitions_list

Field responsible for storing triggers definitions in file. It have to be public because we are using it directly from parser.

GRANT_INFO Table_triggers_list::subject_table_grants[TRG_EVENT_MAX][TRG_ACTION_MAX]

Grant information for each trigger (pair: subject table, trigger definer).

TABLE* Table_triggers_list::trigger_table

TABLE instance for which this triggers list object was created.

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

• sql_trigger.h
• sql_trigger.cc