Bug#49534: multitable IGNORE update with sql_safe_updates

error causes debug assertion

The IGNORE option of the multiple-table UPDATE command was
not intended to suppress errors caused by the
sql_safe_updates mode. This flag will raise an error if the
execution of UPDATE does not use a key for row retrieval,
and should continue do so regardless of the IGNORE option.

However the implementation of IGNORE does not support
exceptions to the rule; it always converts errors to
warnings and cannot be extended. The Internal_error_handler
interface offers the infrastructure to handle individual
errors, making sure that the error raised by
sql_safe_updates is not silenced.

Fixed by implementing an Internal_error_handler and using it
for UPDATE IGNORE commands.
This commit is contained in:
Martin Hansson 2010-02-10 15:37:34 +01:00
commit 630fa243c9
5 changed files with 104 additions and 12 deletions

View file

@ -1188,6 +1188,56 @@ reopen_tables:
}
/**
Implementation of the safe update options during UPDATE IGNORE. This syntax
causes an UPDATE statement to ignore all errors. In safe update mode,
however, we must never ignore the ER_UPDATE_WITHOUT_KEY_IN_SAFE_MODE. There
is a special hook in my_message_sql that will otherwise delete all errors
when the IGNORE option is specified.
In the future, all IGNORE handling should be used with this class and all
traces of the hack outlined below should be removed.
- The parser detects IGNORE option and sets thd->lex->ignore= 1
- In JOIN::optimize, if this is set, then
thd->lex->current_select->no_error gets set.
- In my_message_sql(), if the flag above is set then any error is
unconditionally converted to a warning.
We are moving in the direction of using Internal_error_handler subclasses
to do all such error tweaking, please continue this effort if new bugs
appear.
*/
class Safe_dml_handler : public Internal_error_handler {
private:
bool m_handled_error;
public:
explicit Safe_dml_handler() : m_handled_error(FALSE) {}
bool handle_error(uint sql_errno,
const char *message,
MYSQL_ERROR::enum_warning_level level,
THD *thd)
{
if (level == MYSQL_ERROR::WARN_LEVEL_ERROR &&
sql_errno == ER_UPDATE_WITHOUT_KEY_IN_SAFE_MODE)
{
thd->main_da.set_error_status(thd, sql_errno, message);
m_handled_error= TRUE;
return TRUE;
}
return FALSE;
}
bool handled_error() { return m_handled_error; }
};
/*
Setup multi-update handling and call SELECT to do the join
*/
@ -1216,18 +1266,35 @@ bool mysql_multi_update(THD *thd,
MODE_STRICT_ALL_TABLES));
List<Item> total_list;
Safe_dml_handler handler;
bool using_handler= thd->options & OPTION_SAFE_UPDATES;
if (using_handler)
thd->push_internal_handler(&handler);
res= mysql_select(thd, &select_lex->ref_pointer_array,
table_list, select_lex->with_wild,
total_list,
conds, 0, (ORDER *) NULL, (ORDER *)NULL, (Item *) NULL,
(ORDER *)NULL,
options | SELECT_NO_JOIN_CACHE | SELECT_NO_UNLOCK |
OPTION_SETUP_TABLES_DONE,
result, unit, select_lex);
DBUG_PRINT("info",("res: %d report_error: %d", res,
(int) thd->is_error()));
table_list, select_lex->with_wild,
total_list,
conds, 0, (ORDER *) NULL, (ORDER *)NULL, (Item *) NULL,
(ORDER *)NULL,
options | SELECT_NO_JOIN_CACHE | SELECT_NO_UNLOCK |
OPTION_SETUP_TABLES_DONE,
result, unit, select_lex);
if (using_handler)
{
Internal_error_handler *top_handler= thd->pop_internal_handler();
DBUG_ASSERT(&handler == top_handler);
}
DBUG_PRINT("info",("res: %d report_error: %d", res, (int) thd->is_error()));
res|= thd->is_error();
if (unlikely(res))
/*
Todo: remove below code and make Safe_dml_handler do error processing
instead. That way we can return the actual error instead of
ER_UNKNOWN_ERROR.
*/
if (unlikely(res) && (!using_handler || !handler.handled_error()))
{
/* If we had a another error reported earlier then this will be ignored */
result->send_error(ER_UNKNOWN_ERROR, ER(ER_UNKNOWN_ERROR));