diff options
Diffstat (limited to 'sql/sql_trigger.cc')
| -rw-r--r-- | sql/sql_trigger.cc | 104 |
1 files changed, 77 insertions, 27 deletions
diff --git a/sql/sql_trigger.cc b/sql/sql_trigger.cc index 95734d31411..3552fc596f3 100644 --- a/sql/sql_trigger.cc +++ b/sql/sql_trigger.cc @@ -107,7 +107,9 @@ const LEX_STRING trg_event_type_names[]= }; -static TABLE_LIST *add_table_for_trigger(THD *thd, sp_name *trig); +static int +add_table_for_trigger(THD *thd, sp_name *trig, bool if_exists, + TABLE_LIST ** table); class Handle_old_incorrect_sql_modes_hook: public Unknown_key_hook { @@ -156,6 +158,13 @@ private: */ bool mysql_create_or_drop_trigger(THD *thd, TABLE_LIST *tables, bool create) { + /* + FIXME: The code below takes too many different paths depending on the + 'create' flag, so that the justification for a single function + 'mysql_create_or_drop_trigger', compared to two separate functions + 'mysql_create_trigger' and 'mysql_drop_trigger' is not apparent. + This is a good candidate for a minor refactoring. + */ TABLE *table; bool result= TRUE; String stmt_query; @@ -181,10 +190,6 @@ bool mysql_create_or_drop_trigger(THD *thd, TABLE_LIST *tables, bool create) DBUG_RETURN(TRUE); } - if (!create && - !(tables= add_table_for_trigger(thd, thd->lex->spname))) - DBUG_RETURN(TRUE); - /* We don't allow creating triggers on tables in the 'mysql' schema */ @@ -194,9 +199,6 @@ bool mysql_create_or_drop_trigger(THD *thd, TABLE_LIST *tables, bool create) DBUG_RETURN(TRUE); } - /* We should have only one table in table list. */ - DBUG_ASSERT(tables->next_global == 0); - /* TODO: We should check if user has TRIGGER privilege for table here. Now we just require SUPER privilege for creating/dropping because @@ -211,7 +213,7 @@ bool mysql_create_or_drop_trigger(THD *thd, TABLE_LIST *tables, bool create) DROP for example) so we do the check for privileges. For now there is already a stronger test right above; but when this stronger test will be removed, the test below will hold. Because triggers have the same - nature as functions regarding binlogging: their body is implicitely + nature as functions regarding binlogging: their body is implicitly binlogged, so they share the same danger, so trust_function_creators applies to them too. */ @@ -222,24 +224,52 @@ bool mysql_create_or_drop_trigger(THD *thd, TABLE_LIST *tables, bool create) DBUG_RETURN(TRUE); } - /* We do not allow creation of triggers on temporary tables. */ - if (create && find_temporary_table(thd, tables->db, tables->table_name)) - { - my_error(ER_TRG_ON_VIEW_OR_TEMP_TABLE, MYF(0), tables->alias); - DBUG_RETURN(TRUE); - } - /* We don't want perform our operations while global read lock is held - so we have to wait until its end and then prevent it from occuring + so we have to wait until its end and then prevent it from occurring again until we are done. (Acquiring LOCK_open is not enough because - global read lock is held without helding LOCK_open). + global read lock is held without holding LOCK_open). */ if (wait_if_global_read_lock(thd, 0, 1)) DBUG_RETURN(TRUE); VOID(pthread_mutex_lock(&LOCK_open)); + if (!create) + { + bool if_exists= thd->lex->drop_if_exists; + + if (add_table_for_trigger(thd, thd->lex->spname, if_exists, & tables)) + goto end; + + if (!tables) + { + DBUG_ASSERT(if_exists); + /* + Since the trigger does not exist, there is no associated table, + and therefore : + - no TRIGGER privileges to check, + - no trigger to drop, + - no table to lock/modify, + so the drop statement is successful. + */ + result= FALSE; + /* Still, we need to log the query ... */ + stmt_query.append(thd->query, thd->query_length); + goto end; + } + } + + /* We should have only one table in table list. */ + DBUG_ASSERT(tables->next_global == 0); + + /* We do not allow creation of triggers on temporary tables. */ + if (create && find_temporary_table(thd, tables->db, tables->table_name)) + { + my_error(ER_TRG_ON_VIEW_OR_TEMP_TABLE, MYF(0), tables->alias); + goto end; + } + if (lock_table_names(thd, tables)) goto end; @@ -1145,13 +1175,17 @@ bool Table_triggers_list::get_trigger_info(THD *thd, trg_event_type event, mysql_table_for_trigger() thd - current thread context trig - identifier for trigger + if_exists - treat a not existing trigger as a warning if TRUE + table - pointer to TABLE_LIST object for the table trigger (output) RETURN VALUE - 0 - error - # - pointer to TABLE_LIST object for the table + 0 Success + 1 Error */ -static TABLE_LIST *add_table_for_trigger(THD *thd, sp_name *trig) +static int +add_table_for_trigger(THD *thd, sp_name *trig, bool if_exists, + TABLE_LIST **table) { LEX *lex= thd->lex; char path_buff[FN_REFLEN]; @@ -1162,6 +1196,7 @@ static TABLE_LIST *add_table_for_trigger(THD *thd, sp_name *trig) path_buff, &trigname.trigger_table); DBUG_ENTER("add_table_for_trigger"); + DBUG_ASSERT(table != NULL); strxnmov(path_buff, FN_REFLEN, mysql_data_home, "/", trig->m_db.str, "/", trig->m_name.str, trigname_file_ext, NullS); @@ -1170,30 +1205,45 @@ static TABLE_LIST *add_table_for_trigger(THD *thd, sp_name *trig) if (access(path_buff, F_OK)) { + if (if_exists) + { + push_warning_printf(thd, + MYSQL_ERROR::WARN_LEVEL_NOTE, + ER_TRG_DOES_NOT_EXIST, + ER(ER_TRG_DOES_NOT_EXIST)); + *table= NULL; + DBUG_RETURN(0); + } + my_error(ER_TRG_DOES_NOT_EXIST, MYF(0)); - DBUG_RETURN(0); + DBUG_RETURN(1); } if (!(parser= sql_parse_prepare(&path, thd->mem_root, 1))) - DBUG_RETURN(0); + DBUG_RETURN(1); if (!is_equal(&trigname_file_type, parser->type())) { my_error(ER_WRONG_OBJECT, MYF(0), trig->m_name.str, trigname_file_ext+1, "TRIGGERNAME"); - DBUG_RETURN(0); + DBUG_RETURN(1); } if (parser->parse((gptr)&trigname, thd->mem_root, trigname_file_parameters, 1, &trigger_table_hook)) - DBUG_RETURN(0); + DBUG_RETURN(1); /* We need to reset statement table list to be PS/SP friendly. */ lex->query_tables= 0; lex->query_tables_last= &lex->query_tables; - DBUG_RETURN(sp_add_to_query_tables(thd, lex, trig->m_db.str, - trigname.trigger_table.str, TL_IGNORE)); + *table= sp_add_to_query_tables(thd, lex, trig->m_db.str, + trigname.trigger_table.str, TL_IGNORE); + + if (! *table) + DBUG_RETURN(1); + + DBUG_RETURN(0); } |