summaryrefslogtreecommitdiff
path: root/sql/sql_trigger.h
blob: e2ed4bcc0f4c42c305c0a88870a8157d88a8640e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
/* Copyright (C) 2004-2005 MySQL AB

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA */


/*
  This class holds all information about triggers of table.

  QQ: Will it be merged into TABLE in future ?
*/
class Table_triggers_list: public Sql_alloc
{
  /* Triggers as SPs grouped by event, action_time */
  sp_head           *bodies[TRG_EVENT_MAX][TRG_ACTION_MAX];
  /*
    Copy of TABLE::Field array with field pointers set to TABLE::record[1]
    buffer instead of TABLE::record[0] (used for OLD values in on UPDATE
    trigger and DELETE trigger when it is called for REPLACE).
  */
  Field             **record1_field;
  /*
    During execution of trigger new_field and old_field should point to the
    array of fields representing new or old version of row correspondingly
    (so it can point to TABLE::field or to Tale_triggers_list::record1_field)
  */
  Field             **new_field;
  Field             **old_field;
  /* TABLE instance for which this triggers list object was created */
  TABLE *table;
  /*
    Names of triggers.
    Should correspond to order of triggers on definitions_list,
    used in CREATE/DROP TRIGGER for looking up trigger by name.
  */
  List<LEX_STRING>  names_list;
  /*
    Key representing triggers for this table in set of all stored
    routines used by statement.
    TODO: We won't need this member once triggers namespace will be
    database-wide instead of table-wide because then we will be able
    to use key based on sp_name as for other stored routines.
  */
  LEX_STRING        sroutines_key;

public:
  /*
    Field responsible for storing triggers definitions in file.
    It have to be public because we are using it directly from parser.
  */
  List<LEX_STRING>  definitions_list;
  /*
    List of sql modes for triggers
  */
  List<ulonglong> definition_modes_list;

  Table_triggers_list(TABLE *table_arg):
    record1_field(0), table(table_arg)
  {
    bzero((char *)bodies, sizeof(bodies));
  }
  ~Table_triggers_list();

  bool create_trigger(THD *thd, TABLE_LIST *table);
  bool drop_trigger(THD *thd, TABLE_LIST *table);
  bool process_triggers(THD *thd, trg_event_type event,
                        trg_action_time_type time_type,
                        bool old_row_is_record1)
  {
    int res= 0;

    if (bodies[event][time_type])
    {
      bool save_in_sub_stmt= thd->in_sub_stmt;
#ifndef EMBEDDED_LIBRARY
      /* Surpress OK packets in case if we will execute statements */
      my_bool nsok= thd->net.no_send_ok;
      thd->net.no_send_ok= TRUE;
#endif

      if (old_row_is_record1)
      {
        old_field= record1_field;
        new_field= table->field;
      }
      else
      {
        new_field= record1_field;
        old_field= table->field;
      }

      /*
        FIXME: We should juggle with security context here (because trigger
        should be invoked with creator rights).
      */
      /*
	We disable binlogging, as in SP/functions, even though currently
        triggers can't do updates. When triggers can do updates, someone
        should add such a trigger to rpl_sp.test to verify that the update
        does NOT go into binlog.
      */
      tmp_disable_binlog(thd);
      thd->in_sub_stmt= TRUE;

      res= bodies[event][time_type]->execute_function(thd, 0, 0, 0);

      thd->in_sub_stmt= save_in_sub_stmt;
      reenable_binlog(thd);

#ifndef EMBEDDED_LIBRARY
      thd->net.no_send_ok= nsok;
#endif
    }

    return res;
  }
  bool get_trigger_info(THD *thd, trg_event_type event,
                        trg_action_time_type time_type,
                        LEX_STRING *trigger_name, LEX_STRING *trigger_stmt,
                        ulong *sql_mode);

  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);

  bool has_delete_triggers()
  {
    return (bodies[TRG_EVENT_DELETE][TRG_ACTION_BEFORE] ||
            bodies[TRG_EVENT_DELETE][TRG_ACTION_AFTER]);
  }

  bool has_before_update_triggers()
  {
    return test(bodies[TRG_EVENT_UPDATE][TRG_ACTION_BEFORE]);
  }

  friend class Item_trigger_field;
  friend void sp_cache_routines_and_add_tables_for_triggers(THD *thd, LEX *lex,
                Table_triggers_list *triggers);

private:
  bool prepare_record1_accessors(TABLE *table);
};

extern const LEX_STRING trg_action_time_type_names[];
extern const LEX_STRING trg_event_type_names[];