MySQL 8.3.0
Source Code Documentation
trigger.h
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1/*
2 Copyright (c) 2013, 2023, Oracle and/or its affiliates.
3
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22 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
23
24#ifndef TRIGGER_H_INCLUDED
25#define TRIGGER_H_INCLUDED
26
27#include <stdint.h>
28#include <string.h>
29
30#include "my_config.h"
31#ifdef HAVE_SYS_TIME_H
32#include <sys/time.h>
33#endif
34#include <sys/types.h>
35
36#include "lex_string.h"
37#include "my_inttypes.h"
38#include "mysql_com.h"
39#include "sql/table.h" // GRANT_INFO
40#include "sql/trigger_def.h" // enum_trigger_event_type
41
43class String;
44class THD;
45class sp_head;
46struct MEM_ROOT;
47
48using sql_mode_t = uint64_t;
49
50/**
51 This class represents a trigger object.
52 Trigger can be created, initialized, parsed and executed.
53
54 Trigger attributes are usually stored on the memory root of the subject table.
55 Trigger object however can exist when the subject table does not. In this
56 case, trigger attributes are stored on a separate memory root.
57
58 Trigger objects are created in two ways:
59
60 1. loading from Data Dictionary (by Trigger_loader)
61
62 In this case Trigger object is initialized from the data
63 which is directly available in data dictionary;
64
65 @see Trigger::create_from_dd().
66
67 2. creating a new Trigger object that represents the trigger object being
68 created by CREATE TRIGGER statement (by Table_trigger_dispatcher).
69
70 In this case Trigger object is created temporarily.
71
72 @see Trigger::create_from_parser().
73*/
74class Trigger {
75 public:
76 static Trigger *create_from_parser(THD *thd, TABLE *subject_table,
77 String *binlog_create_trigger_stmt);
78
79 static Trigger *create_from_dd(
80 MEM_ROOT *mem_root, const LEX_CSTRING &trigger_name,
81 const LEX_CSTRING &db_name, const LEX_CSTRING &subject_table_name,
82 const LEX_CSTRING &definition, const LEX_CSTRING &definition_utf8,
83 sql_mode_t sql_mode, const LEX_CSTRING &definer_user,
84 const LEX_CSTRING &definer_host, const LEX_CSTRING &client_cs_name,
85 const LEX_CSTRING &connection_cl_name, const LEX_CSTRING &db_cl_name,
86 enum_trigger_event_type trg_event_type,
87 enum_trigger_action_time_type trg_time_type, uint action_order,
88 my_timeval created_timestamp);
89
90 /**
91 Constructs CREATE TRIGGER statement taking into account a value of
92 the DEFINER clause.
93
94 The point of this method is to create canonical forms of CREATE TRIGGER
95 statement for writing into the binlog.
96
97 @note
98 A statement for the binlog form must preserve FOLLOWS/PRECEDES clause
99 if it was in the original statement. The reason for that difference is this:
100
101 - the Data Dictionary preserves the trigger execution order
102 (action_order), thus FOLLOWS/PRECEDES clause is not needed.
103
104 - moreover, FOLLOWS/PRECEDES clause usually makes problem in mysqldump,
105 because CREATE TRIGGER statement will have a reference to
106 not-yet-existing trigger (which is about to be created right after this
107 one).
108
109 - thus, FOLLOWS/PRECEDES must not be stored in the Data Dictionary.
110
111 - on the other hand, the binlog contains statements in the user order (as
112 the user executes them). Thus, it is important to preserve
113 FOLLOWS/PRECEDES clause if the user has specified it so that the trigger
114 execution order on master and slave will be the same.
115
116 @param thd thread context
117 @param[out] binlog_query well-formed CREATE TRIGGER statement for putting
118 into binlog (after successful execution)
119 @param def_user user part of a definer value
120 @param def_host host part of a definer value
121
122 @return Operation status.
123 @retval false Success
124 @retval true Failure
125 */
127 THD *thd, String *binlog_query, const LEX_CSTRING &def_user,
128 const LEX_CSTRING &def_host);
129
130 public:
131 bool execute(THD *thd);
132
133 bool parse(THD *thd, bool is_upgrade);
134
135 void add_tables_and_routines(THD *thd, Query_tables_list *prelocking_ctx,
136 Table_ref *table_list);
137
138 void print_upgrade_warning(THD *thd);
139
140 public:
141 /************************************************************************
142 * Attribute accessors.
143 ***********************************************************************/
144
145 const LEX_CSTRING &get_db_name() const { return m_db_name; }
146
149 }
150
151 const LEX_CSTRING &get_trigger_name() const { return m_trigger_name; }
152
153 const LEX_CSTRING &get_definition() const { return m_definition; }
154
156
158
159 const LEX_CSTRING &get_definer() const { return m_definer; }
160
161 const LEX_CSTRING &get_definer_user() const { return m_definer_user; }
162
163 const LEX_CSTRING &get_definer_host() const { return m_definer_host; }
164
166
169 }
170
171 const LEX_CSTRING &get_db_cl_name() const { return m_db_cl_name; }
172
174
175 const LEX_CSTRING &get_event_as_string() const;
176
178 return m_action_time;
179 }
180
182
184 return m_created_timestamp.m_tv_sec == 0 &&
186 }
187
189
191
192 void set_action_order(ulonglong action_order) {
193 m_action_order = action_order;
194 }
195
196 sp_head *get_sp() { return m_sp; }
197
199
200 bool has_parse_error() const { return m_has_parse_error; }
201
202 const char *get_parse_error_message() const { return m_parse_error_message; }
203
204 /**
205 Construct a full CREATE TRIGGER statement from Trigger's data members.
206
207 @param [in] thd Thread context
208 @param [out] full_trigger_definition Place where a CREATE TRIGGER
209 statement be stored.
210
211 @return Operation status
212 @retval true Failure
213 @retval false Success
214 */
215
216 bool create_full_trigger_definition(const THD *thd,
217 String *full_trigger_definition) const;
218
219 private:
220 Trigger(const LEX_CSTRING &trigger_name, MEM_ROOT *mem_root,
222 const LEX_CSTRING &definition, const LEX_CSTRING &definition_utf8,
223 sql_mode_t sql_mode, const LEX_CSTRING &definer_user,
224 const LEX_CSTRING &definer_host, const LEX_CSTRING &client_cs_name,
225 const LEX_CSTRING &connection_cl_name, const LEX_CSTRING &db_cl_name,
226 enum_trigger_event_type event_type,
227 enum_trigger_action_time_type action_time, uint action_order,
228 my_timeval created_timestamp);
229
230 public:
231 ~Trigger();
232
233 private:
234 void set_trigger_name(const LEX_CSTRING &trigger_name) {
235 m_trigger_name = trigger_name;
236 }
237
238 void set_trigger_def(const LEX_CSTRING &trigger_def) {
239 m_definition = trigger_def;
240 }
241
242 void set_trigger_def_utf8(const LEX_CSTRING &trigger_def_utf8) {
243 m_definition_utf8 = trigger_def_utf8;
244 }
245
246 void set_parse_error_message(const char *error_message) {
247 m_has_parse_error = true;
248 snprintf(m_parse_error_message, sizeof(m_parse_error_message), "%s",
249 error_message);
250 }
251
252 /**
253 Memory root to store all data of this Trigger object.
254
255 This can be a pointer to the subject table memory root, or it can be a
256 pointer to a dedicated memory root if subject table does not exist.
257 */
259
260 /**
261 Full trigger definition reconstructed from a data loaded from the table
262 mysql.trigger.
263 */
265
266 private:
267 /************************************************************************
268 * Mandatory trigger attributes loaded from data dictionary.
269 * All these strings are allocated on m_mem_root.
270 ***********************************************************************/
271
272 /// Database name.
274
275 /// Table name.
277
278 /// Trigger definition to save in DD.
280
281 /// Trigger definition in UTF8 to save in DD.
283
284 /// Trigger sql-mode.
286
287 /// Trigger definer.
289
290 /// Trigger definer (user part).
292
293 /// Trigger definer (host part).
295
296 /// Character set context, used for parsing and executing trigger.
298
299 /// Collation name of the connection within one a trigger are created.
301
302 /// Default database collation.
304
305 /// Trigger event.
307
308 /// Trigger action time.
310
311 /**
312 Current time when the trigger was created (measured in milliseconds since
313 since 0 hours, 0 minutes, 0 seconds, January 1, 1970, UTC). This is the
314 value of CREATED attribute.
315
316 There is special value -- zero means CREATED is not set (NULL).
317 */
319
320 /**
321 Action_order value for the trigger. Action_order is the ordinal position
322 of the trigger in the list of triggers with the same EVENT_MANIPULATION,
323 CONDITION_TIMING, and ACTION_ORIENTATION.
324 */
326
327 private:
328 /************************************************************************
329 * All these strings are allocated on the trigger table's mem-root.
330 ***********************************************************************/
331
332 /// Trigger name.
334
335 private:
336 /************************************************************************
337 * Other attributes.
338 ***********************************************************************/
339
340 /// Grant information for the trigger.
342
343 /// Pointer to the sp_head corresponding to the trigger.
345
346 /// This flags specifies whether the trigger has parse error or not.
348
349 /**
350 This error will be displayed when the user tries to manipulate or invoke
351 triggers on a table that has broken triggers. It will get set only once
352 per statement and thus will contain the first parse error encountered in
353 the trigger file.
354 */
356};
357
358///////////////////////////////////////////////////////////////////////////
359
360#endif // TRIGGER_H_INCLUDED
Definition: sql_lex.h:2565
Using this class is fraught with peril, and you need to be very careful when doing so.
Definition: sql_string.h:166
For each client connection we create a separate thread with THD serving as a thread/connection descri...
Definition: sql_lexer_thd.h:35
Definition: table.h:2853
This class represents a trigger object.
Definition: trigger.h:74
sp_head * m_sp
Pointer to the sp_head corresponding to the trigger.
Definition: trigger.h:344
GRANT_INFO * get_subject_table_grant()
Definition: trigger.h:198
bool has_parse_error() const
Definition: trigger.h:200
enum_trigger_event_type m_event
Trigger event.
Definition: trigger.h:306
LEX_CSTRING m_client_cs_name
Character set context, used for parsing and executing trigger.
Definition: trigger.h:297
ulonglong get_action_order() const
Definition: trigger.h:190
LEX_CSTRING m_db_name
Database name.
Definition: trigger.h:273
LEX_CSTRING m_connection_cl_name
Collation name of the connection within one a trigger are created.
Definition: trigger.h:300
enum_trigger_action_time_type get_action_time() const
Definition: trigger.h:177
const LEX_CSTRING & get_definer_user() const
Definition: trigger.h:161
~Trigger()
Destroy associated SP (if any).
Definition: trigger.cc:361
LEX_CSTRING m_definition_utf8
Trigger definition in UTF8 to save in DD.
Definition: trigger.h:282
my_timeval m_created_timestamp
Current time when the trigger was created (measured in milliseconds since since 0 hours,...
Definition: trigger.h:318
static Trigger * create_from_dd(MEM_ROOT *mem_root, const LEX_CSTRING &trigger_name, const LEX_CSTRING &db_name, const LEX_CSTRING &subject_table_name, const LEX_CSTRING &definition, const LEX_CSTRING &definition_utf8, sql_mode_t sql_mode, const LEX_CSTRING &definer_user, const LEX_CSTRING &definer_host, const LEX_CSTRING &client_cs_name, const LEX_CSTRING &connection_cl_name, const LEX_CSTRING &db_cl_name, enum_trigger_event_type trg_event_type, enum_trigger_action_time_type trg_time_type, uint action_order, my_timeval created_timestamp)
Creates a new Trigger-instance with the state loaded from the Data Dictionary.
Definition: trigger.cc:305
const LEX_CSTRING & get_action_time_as_string() const
Definition: trigger.cc:153
void set_action_order(ulonglong action_order)
Definition: trigger.h:192
bool m_has_parse_error
This flags specifies whether the trigger has parse error or not.
Definition: trigger.h:347
bool parse(THD *thd, bool is_upgrade)
Parse CREATE TRIGGER statement.
Definition: trigger.cc:433
char m_parse_error_message[MYSQL_ERRMSG_SIZE]
This error will be displayed when the user tries to manipulate or invoke triggers on a table that has...
Definition: trigger.h:355
bool create_full_trigger_definition(const THD *thd, String *full_trigger_definition) const
Construct a full CREATE TRIGGER statement from Trigger's data members.
Definition: trigger.cc:398
ulonglong m_action_order
Action_order value for the trigger.
Definition: trigger.h:325
my_timeval get_created_timestamp() const
Definition: trigger.h:188
const LEX_CSTRING & get_trigger_name() const
Definition: trigger.h:151
const char * get_parse_error_message() const
Definition: trigger.h:202
const LEX_CSTRING & get_definition_utf8() const
Definition: trigger.h:155
LEX_CSTRING m_trigger_name
Trigger name.
Definition: trigger.h:333
LEX_CSTRING m_db_cl_name
Default database collation.
Definition: trigger.h:303
const LEX_CSTRING & get_definer() const
Definition: trigger.h:159
sql_mode_t m_sql_mode
Trigger sql-mode.
Definition: trigger.h:285
LEX_CSTRING m_definition
Trigger definition to save in DD.
Definition: trigger.h:279
bool execute(THD *thd)
Execute trigger's body.
Definition: trigger.cc:373
MEM_ROOT * m_mem_root
Memory root to store all data of this Trigger object.
Definition: trigger.h:258
const LEX_CSTRING & get_db_cl_name() const
Definition: trigger.h:171
enum_trigger_event_type get_event() const
Definition: trigger.h:173
void set_trigger_def_utf8(const LEX_CSTRING &trigger_def_utf8)
Definition: trigger.h:242
void add_tables_and_routines(THD *thd, Query_tables_list *prelocking_ctx, Table_ref *table_list)
Add tables and routines used by trigger to the set of elements used by statement.
Definition: trigger.cc:624
LEX_CSTRING m_definer
Trigger definer.
Definition: trigger.h:288
const LEX_CSTRING & get_definition() const
Definition: trigger.h:153
bool is_created_timestamp_null() const
Definition: trigger.h:183
LEX_CSTRING m_subject_table_name
Table name.
Definition: trigger.h:276
void set_parse_error_message(const char *error_message)
Definition: trigger.h:246
sql_mode_t get_sql_mode() const
Definition: trigger.h:157
LEX_CSTRING m_definer_user
Trigger definer (user part).
Definition: trigger.h:291
const LEX_CSTRING & get_connection_cl_name() const
Definition: trigger.h:167
Trigger(const LEX_CSTRING &trigger_name, MEM_ROOT *mem_root, const LEX_CSTRING &db_name, const LEX_CSTRING &table_name, const LEX_CSTRING &definition, const LEX_CSTRING &definition_utf8, sql_mode_t sql_mode, const LEX_CSTRING &definer_user, const LEX_CSTRING &definer_host, const LEX_CSTRING &client_cs_name, const LEX_CSTRING &connection_cl_name, const LEX_CSTRING &db_cl_name, enum_trigger_event_type event_type, enum_trigger_action_time_type action_time, uint action_order, my_timeval created_timestamp)
Trigger constructor.
Definition: trigger.cc:325
LEX_CSTRING m_definer_host
Trigger definer (host part).
Definition: trigger.h:294
void set_trigger_def(const LEX_CSTRING &trigger_def)
Definition: trigger.h:238
GRANT_INFO m_subject_table_grant
Grant information for the trigger.
Definition: trigger.h:341
const LEX_CSTRING & get_subject_table_name() const
Definition: trigger.h:147
const LEX_CSTRING & get_event_as_string() const
Definition: trigger.cc:157
const LEX_CSTRING & get_db_name() const
Definition: trigger.h:145
static bool construct_create_trigger_stmt_with_definer(THD *thd, String *binlog_query, const LEX_CSTRING &def_user, const LEX_CSTRING &def_host)
Constructs CREATE TRIGGER statement taking into account a value of the DEFINER clause.
Definition: trigger.cc:127
const LEX_CSTRING & get_definer_host() const
Definition: trigger.h:163
const LEX_CSTRING & get_client_cs_name() const
Definition: trigger.h:165
void print_upgrade_warning(THD *thd)
Print upgrade warnings (if any).
Definition: trigger.cc:667
LEX_CSTRING m_full_trigger_definition
Full trigger definition reconstructed from a data loaded from the table mysql.trigger.
Definition: trigger.h:264
enum_trigger_action_time_type m_action_time
Trigger action time.
Definition: trigger.h:309
sp_head * get_sp()
Definition: trigger.h:196
void set_trigger_name(const LEX_CSTRING &trigger_name)
Definition: trigger.h:234
static Trigger * create_from_parser(THD *thd, TABLE *subject_table, String *binlog_create_trigger_stmt)
Creates a new Trigger-instance with the state from the parser.
Definition: trigger.cc:181
sp_head represents one instance of a stored program.
Definition: sp_head.h:382
static MEM_ROOT mem_root
Definition: client_plugin.cc:113
uint64_t sql_mode_t
Definition: dd_event.h:38
Some integer typedefs for easier portability.
unsigned long long int ulonglong
Definition: my_inttypes.h:55
Common definition between mysql server & client.
#define MYSQL_ERRMSG_SIZE
Max length of a error message.
Definition: mysql_com.h:886
static const char * sql_mode
Definition: mysqlslap.cc:198
const char * table_name
Definition: rules_table_service.cc:55
const char * db_name
Definition: rules_table_service.cc:54
The current state of the privilege checking process for the current user, SQL statement and SQL objec...
Definition: table.h:366
The MEM_ROOT is a simple arena, where allocations are carved out of larger blocks.
Definition: my_alloc.h:82
Definition: mysql_lex_string.h:39
Definition: table.h:1403
Replacement of system's struct timeval to ensure we can carry 64 bit values even on a platform which ...
Definition: my_time_t.h:44
int64_t m_tv_sec
Definition: my_time_t.h:45
int64_t m_tv_usec
Definition: my_time_t.h:46
Include file for Sun RPC to compile out of the box.
This file defines all base public constants related to triggers in MySQL.
enum_trigger_event_type
Constants to enumerate possible event types on which triggers can be fired.
Definition: trigger_def.h:41
enum_trigger_action_time_type
Constants to enumerate possible timings when triggers can be fired.
Definition: trigger_def.h:51