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mariadb/sql/sql_update.cc
unknown 78422442df Preparatory (and the most problematic) patch for Bug#7306 
"the server side preparedStatement error for LIMIT placeholder",
which moves all uses of LIMIT clause from PREPARE to OPTIMIZE
and later steps.
After-review fixes.


mysql-test/r/group_min_max.result:
  Test results fixed for EXPLAINs when using GROUP_MIN_MAX access plan.
sql/item_subselect.cc:
  Move setting of the internal LIMIT used for IN/ALL/ANY/EXISTS 
  subqueries to one place: Item_exists_subselect::fix_length_and_dec().
  This implies that unit->select_limit_cnt is not set until the item is 
  fixed. This is OK, as now LIMIT values are not used until JOIN::optimize.
sql/mysql_priv.h:
  setup_tables no longer needs a special flag for the case when
  it's called from JOIN::reinit() (we don't need to call setup_tables
  between two executions of a correlated subquery).
sql/opt_range.cc:
  Fix a glitch in GROUP_MIN_MAX access plan: we should use table metadata,
  not field data, to evaluate max_used_key_length, which is then
  used for explain.
sql/sp.cc:
  - setup_tables signature changed.
sql/sql_base.cc:
  - setup_tables no longer needs a special mode for subqueries.
    Unused checks were removed.
sql/sql_delete.cc:
  - setup_tables signature changed
sql/sql_help.cc:
  - setup_tables signature changed
sql/sql_insert.cc:
  - setup_tables signature changed
sql/sql_lex.cc:
  Consolidate setting of internal LIMIT for IN/ALL/ANY/EXISTS subqeries
  in one place, and hence remove it from st_select_lex::test_limit().
sql/sql_lex.h:
  Cleanup signature of st_select_lex_unit::init_prepare_fake_select_lex().
sql/sql_load.cc:
  - setup_tables signature changed
sql/sql_olap.cc:
  - setup_tables signature changed
sql/sql_parse.cc:
  - st_select_lex_unit::set_limit() signature changed
sql/sql_select.cc:
  Move setting of JOIN::select_limit from JOIN::prepare
  to JOIN::optimize. At prepare, limit is unknown yet.
  Remove excessive cleanups from JOIN::reinit which were overwriting
  join->join_tab[i]->table->used_keys. This fixes the bug which was triggered
  by the change in item_subselect.cc.
sql/sql_union.cc:
  Class st_select_lex_unit was changed to avoid calls to 
   st_select_lex_unit::set_limit from places where it may be unknown.
  Now unit->select_limit_cnt is set at ::exec(). 
  st_select_lex_unit::init_prepare_fake_select_lex(): 
   - move out set_limit functionality
   - remove a few lines of dead code.
  st_select_lex_unit::prepare():
    - now we don't call set_limit at the time of prepare, so the value  
      of unit->select_limit_cnt may be unknown here. Use sl->select_limit
      instead.
  st_select_lex_unit::exec():
    - cleanup
    - call set_limit explicitly as it has been moved out of 
     init_prepare_fake_select_lex.
sql/sql_update.cc:
  - setup_tables signature changed
2005-05-30 20:54:37 +04:00

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/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult 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 */
/*
Single table and multi table updates of tables.
Multi-table updates were introduced by Sinisa & Monty
*/
#include "mysql_priv.h"
#include "sql_select.h"
#include "sp_head.h"
#include "sql_trigger.h"
static bool safe_update_on_fly(JOIN_TAB *join_tab, List<Item> *fields);
/* Return 0 if row hasn't changed */
static bool compare_record(TABLE *table, query_id_t query_id)
{
if (table->s->blob_fields + table->s->varchar_fields == 0)
return cmp_record(table,record[1]);
/* Compare null bits */
if (memcmp(table->null_flags,
table->null_flags+table->s->rec_buff_length,
table->s->null_bytes))
return TRUE; // Diff in NULL value
/* Compare updated fields */
for (Field **ptr=table->field ; *ptr ; ptr++)
{
if ((*ptr)->query_id == query_id &&
(*ptr)->cmp_binary_offset(table->s->rec_buff_length))
return TRUE;
}
return FALSE;
}
/*
check that all fields are real fields
SYNOPSIS
check_fields()
thd thread handler
items Items for check
RETURN
TRUE Items can't be used in UPDATE
FALSE Items are OK
*/
static bool check_fields(THD *thd, List<Item> &items)
{
List_iterator<Item> it(items);
Item *item;
Item_field *field;
while ((item= it++))
{
if (!(field= item->filed_for_view_update()))
{
/* item has name, because it comes from VIEW SELECT list */
my_error(ER_NONUPDATEABLE_COLUMN, MYF(0), item->name);
return TRUE;
}
/*
we make temporary copy of Item_field, to avoid influence of changing
result_field on Item_ref which refer on this field
*/
thd->change_item_tree(it.ref(), new Item_field(thd, field));
}
return FALSE;
}
/*
Process usual UPDATE
SYNOPSIS
mysql_update()
thd thread handler
fields fields for update
values values of fields for update
conds WHERE clause expression
order_num number of elemen in ORDER BY clause
order ORDER BY clause list
limit limit clause
handle_duplicates how to handle duplicates
RETURN
0 - OK
2 - privilege check and openning table passed, but we need to convert to
multi-update because of view substitution
1 - error
*/
int mysql_update(THD *thd,
TABLE_LIST *table_list,
List<Item> &fields,
List<Item> &values,
COND *conds,
uint order_num, ORDER *order,
ha_rows limit,
enum enum_duplicates handle_duplicates, bool ignore)
{
bool using_limit= limit != HA_POS_ERROR;
bool safe_update= thd->options & OPTION_SAFE_UPDATES;
bool used_key_is_modified, transactional_table;
int res;
int error=0;
uint used_index;
#ifndef NO_EMBEDDED_ACCESS_CHECKS
uint want_privilege;
#endif
uint table_count= 0;
query_id_t query_id=thd->query_id, timestamp_query_id;
ha_rows updated, found;
key_map old_used_keys;
TABLE *table;
SQL_SELECT *select;
READ_RECORD info;
SELECT_LEX *select_lex= &thd->lex->select_lex;
DBUG_ENTER("mysql_update");
LINT_INIT(timestamp_query_id);
if (open_tables(thd, &table_list, &table_count))
DBUG_RETURN(1);
if (table_list->multitable_view)
{
DBUG_ASSERT(table_list->view != 0);
DBUG_PRINT("info", ("Switch to multi-update"));
/* pass counter value */
thd->lex->table_count= table_count;
/* convert to multiupdate */
return 2;
}
if (lock_tables(thd, table_list, table_count) ||
mysql_handle_derived(thd->lex, &mysql_derived_prepare) ||
(thd->fill_derived_tables() &&
mysql_handle_derived(thd->lex, &mysql_derived_filling)))
DBUG_RETURN(1);
thd->proc_info="init";
table= table_list->table;
table->file->info(HA_STATUS_VARIABLE | HA_STATUS_NO_LOCK);
/* Calculate "table->used_keys" based on the WHERE */
table->used_keys= table->s->keys_in_use;
table->quick_keys.clear_all();
#ifndef NO_EMBEDDED_ACCESS_CHECKS
/* TABLE_LIST contain right privilages request */
want_privilege= table_list->grant.want_privilege;
#endif
if (mysql_prepare_update(thd, table_list, &conds, order_num, order))
DBUG_RETURN(1);
old_used_keys= table->used_keys; // Keys used in WHERE
/*
Change the query_id for the timestamp column so that we can
check if this is modified directly
*/
if (table->timestamp_field)
{
timestamp_query_id=table->timestamp_field->query_id;
table->timestamp_field->query_id=thd->query_id-1;
}
/* Check the fields we are going to modify */
#ifndef NO_EMBEDDED_ACCESS_CHECKS
table_list->grant.want_privilege= table->grant.want_privilege= want_privilege;
#endif
{
bool res;
select_lex->no_wrap_view_item= 1;
res= setup_fields(thd, 0, table_list, fields, 1, 0, 0);
select_lex->no_wrap_view_item= 0;
if (res)
DBUG_RETURN(1); /* purecov: inspected */
}
if (table_list->view && check_fields(thd, fields))
{
DBUG_RETURN(1);
}
if (!table_list->updatable || check_key_in_view(thd, table_list))
{
my_error(ER_NON_UPDATABLE_TABLE, MYF(0), table_list->alias, "UPDATE");
DBUG_RETURN(1);
}
if (table->timestamp_field)
{
// Don't set timestamp column if this is modified
if (table->timestamp_field->query_id == thd->query_id)
table->timestamp_field_type= TIMESTAMP_NO_AUTO_SET;
else
table->timestamp_field->query_id=timestamp_query_id;
}
#ifndef NO_EMBEDDED_ACCESS_CHECKS
/* Check values */
table_list->grant.want_privilege= table->grant.want_privilege=
(SELECT_ACL & ~table->grant.privilege);
#endif
if (setup_fields(thd, 0, table_list, values, 1, 0, 0))
{
free_underlaid_joins(thd, select_lex);
DBUG_RETURN(1); /* purecov: inspected */
}
// Don't count on usage of 'only index' when calculating which key to use
table->used_keys.clear_all();
select= make_select(table, 0, 0, conds, 0, &error);
if (error ||
(select && select->check_quick(thd, safe_update, limit)) || !limit)
{
delete select;
free_underlaid_joins(thd, select_lex);
if (error)
{
DBUG_RETURN(1); // Error in where
}
send_ok(thd); // No matching records
DBUG_RETURN(0);
}
/* If running in safe sql mode, don't allow updates without keys */
if (table->quick_keys.is_clear_all())
{
thd->server_status|=SERVER_QUERY_NO_INDEX_USED;
if (safe_update && !using_limit)
{
my_message(ER_UPDATE_WITHOUT_KEY_IN_SAFE_MODE,
ER(ER_UPDATE_WITHOUT_KEY_IN_SAFE_MODE), MYF(0));
goto err;
}
}
init_ftfuncs(thd, select_lex, 1);
/* Check if we are modifying a key that we are used to search with */
if (select && select->quick)
{
used_index= select->quick->index;
used_key_is_modified= (!select->quick->unique_key_range() &&
select->quick->check_if_keys_used(&fields));
}
else if ((used_index=table->file->key_used_on_scan) < MAX_KEY)
used_key_is_modified=check_if_key_used(table, used_index, fields);
else
used_key_is_modified=0;
if (used_key_is_modified || order)
{
/*
We can't update table directly; We must first search after all
matching rows before updating the table!
*/
table->file->extra(HA_EXTRA_RETRIEVE_ALL_COLS);
if (used_index < MAX_KEY && old_used_keys.is_set(used_index))
{
table->key_read=1;
table->file->extra(HA_EXTRA_KEYREAD);
}
if (order)
{
/*
Doing an ORDER BY; Let filesort find and sort the rows we are going
to update
*/
uint length;
SORT_FIELD *sortorder;
ha_rows examined_rows;
table->sort.io_cache = (IO_CACHE *) my_malloc(sizeof(IO_CACHE),
MYF(MY_FAE | MY_ZEROFILL));
if (!(sortorder=make_unireg_sortorder(order, &length)) ||
(table->sort.found_records = filesort(thd, table, sortorder, length,
select, limit,
&examined_rows))
== HA_POS_ERROR)
{
free_io_cache(table);
goto err;
}
/*
Filesort has already found and selected the rows we want to update,
so we don't need the where clause
*/
delete select;
select= 0;
}
else
{
/*
We are doing a search on a key that is updated. In this case
we go trough the matching rows, save a pointer to them and
update these in a separate loop based on the pointer.
*/
IO_CACHE tempfile;
if (open_cached_file(&tempfile, mysql_tmpdir,TEMP_PREFIX,
DISK_BUFFER_SIZE, MYF(MY_WME)))
goto err;
/* If quick select is used, initialize it before retrieving rows. */
if (select && select->quick && select->quick->reset())
goto err;
init_read_record(&info,thd,table,select,0,1);
thd->proc_info="Searching rows for update";
uint tmp_limit= limit;
while (!(error=info.read_record(&info)) && !thd->killed)
{
if (!(select && select->skip_record()))
{
table->file->position(table->record[0]);
if (my_b_write(&tempfile,table->file->ref,
table->file->ref_length))
{
error=1; /* purecov: inspected */
break; /* purecov: inspected */
}
if (!--limit && using_limit)
{
error= -1;
break;
}
}
}
if (thd->killed && !error)
error= 1; // Aborted
limit= tmp_limit;
end_read_record(&info);
/* Change select to use tempfile */
if (select)
{
delete select->quick;
if (select->free_cond)
delete select->cond;
select->quick=0;
select->cond=0;
}
else
{
select= new SQL_SELECT;
select->head=table;
}
if (reinit_io_cache(&tempfile,READ_CACHE,0L,0,0))
error=1; /* purecov: inspected */
select->file=tempfile; // Read row ptrs from this file
if (error >= 0)
goto err;
}
if (table->key_read)
{
table->key_read=0;
table->file->extra(HA_EXTRA_NO_KEYREAD);
}
}
if (ignore)
table->file->extra(HA_EXTRA_IGNORE_DUP_KEY);
if (select && select->quick && select->quick->reset())
goto err;
init_read_record(&info,thd,table,select,0,1);
updated= found= 0;
thd->count_cuted_fields= CHECK_FIELD_WARN; /* calc cuted fields */
thd->cuted_fields=0L;
thd->proc_info="Updating";
query_id=thd->query_id;
transactional_table= table->file->has_transactions();
thd->no_trans_update= 0;
thd->abort_on_warning= test(!ignore &&
(thd->variables.sql_mode &
(MODE_STRICT_TRANS_TABLES |
MODE_STRICT_ALL_TABLES)));
while (!(error=info.read_record(&info)) && !thd->killed)
{
if (!(select && select->skip_record()))
{
store_record(table,record[1]);
if (fill_record_n_invoke_before_triggers(thd, fields, values, 0,
table->triggers,
TRG_EVENT_UPDATE))
break; /* purecov: inspected */
found++;
if (compare_record(table, query_id))
{
if ((res= table_list->view_check_option(thd, ignore)) !=
VIEW_CHECK_OK)
{
found--;
if (res == VIEW_CHECK_SKIP)
continue;
else if (res == VIEW_CHECK_ERROR)
{
error= 1;
break;
}
}
if (!(error=table->file->update_row((byte*) table->record[1],
(byte*) table->record[0])))
{
updated++;
thd->no_trans_update= !transactional_table;
if (table->triggers &&
table->triggers->process_triggers(thd, TRG_EVENT_UPDATE,
TRG_ACTION_AFTER, TRUE))
{
error= 1;
break;
}
}
else if (!ignore || error != HA_ERR_FOUND_DUPP_KEY)
{
thd->fatal_error(); // Force error message
table->file->print_error(error,MYF(0));
error= 1;
break;
}
}
if (!--limit && using_limit)
{
error= -1; // Simulate end of file
break;
}
}
else
table->file->unlock_row();
thd->row_count++;
}
if (thd->killed && !error)
error= 1; // Aborted
end_read_record(&info);
free_io_cache(table); // If ORDER BY
delete select;
thd->proc_info="end";
VOID(table->file->extra(HA_EXTRA_NO_IGNORE_DUP_KEY));
/*
Invalidate the table in the query cache if something changed.
This must be before binlog writing and ha_autocommit_...
*/
if (updated)
{
query_cache_invalidate3(thd, table_list, 1);
}
if ((updated || (error < 0)) && (error <= 0 || !transactional_table))
{
if (mysql_bin_log.is_open())
{
if (error <= 0)
thd->clear_error();
Query_log_event qinfo(thd, thd->query, thd->query_length,
transactional_table, FALSE);
if (mysql_bin_log.write(&qinfo) && transactional_table)
error=1; // Rollback update
}
if (!transactional_table)
thd->options|=OPTION_STATUS_NO_TRANS_UPDATE;
}
if (transactional_table)
{
if (ha_autocommit_or_rollback(thd, error >= 0))
error=1;
}
if (thd->lock)
{
mysql_unlock_tables(thd, thd->lock);
thd->lock=0;
}
free_underlaid_joins(thd, select_lex);
if (error < 0)
{
char buff[STRING_BUFFER_USUAL_SIZE];
sprintf(buff, ER(ER_UPDATE_INFO), (ulong) found, (ulong) updated,
(ulong) thd->cuted_fields);
thd->row_count_func=
(thd->client_capabilities & CLIENT_FOUND_ROWS) ? found : updated;
send_ok(thd, (ulong) thd->row_count_func,
thd->insert_id_used ? thd->insert_id() : 0L,buff);
DBUG_PRINT("info",("%d records updated",updated));
}
thd->count_cuted_fields= CHECK_FIELD_IGNORE; /* calc cuted fields */
thd->abort_on_warning= 0;
free_io_cache(table);
DBUG_RETURN((error >= 0 || thd->net.report_error) ? 1 : 0);
err:
delete select;
free_underlaid_joins(thd, select_lex);
if (table->key_read)
{
table->key_read=0;
table->file->extra(HA_EXTRA_NO_KEYREAD);
}
thd->abort_on_warning= 0;
DBUG_RETURN(1);
}
/*
Prepare items in UPDATE statement
SYNOPSIS
mysql_prepare_update()
thd - thread handler
table_list - global/local table list
conds - conditions
order_num - number of ORDER BY list entries
order - ORDER BY clause list
RETURN VALUE
FALSE OK
TRUE error
*/
bool mysql_prepare_update(THD *thd, TABLE_LIST *table_list,
Item **conds, uint order_num, ORDER *order)
{
TABLE *table= table_list->table;
TABLE_LIST tables;
List<Item> all_fields;
SELECT_LEX *select_lex= &thd->lex->select_lex;
DBUG_ENTER("mysql_prepare_update");
#ifndef NO_EMBEDDED_ACCESS_CHECKS
table_list->grant.want_privilege= table->grant.want_privilege=
(SELECT_ACL & ~table->grant.privilege);
#endif
bzero((char*) &tables,sizeof(tables)); // For ORDER BY
tables.table= table;
tables.alias= table_list->alias;
if (setup_tables(thd, table_list, conds, &select_lex->leaf_tables, FALSE) ||
setup_conds(thd, table_list, select_lex->leaf_tables, conds) ||
select_lex->setup_ref_array(thd, order_num) ||
setup_order(thd, select_lex->ref_pointer_array,
table_list, all_fields, all_fields, order) ||
setup_ftfuncs(select_lex))
DBUG_RETURN(TRUE);
/* Check that we are not using table that we are updating in a sub select */
if (unique_table(table_list, table_list->next_global))
{
my_error(ER_UPDATE_TABLE_USED, MYF(0), table_list->table_name);
DBUG_RETURN(TRUE);
}
select_lex->fix_prepare_information(thd, conds);
DBUG_RETURN(FALSE);
}
/***************************************************************************
Update multiple tables from join
***************************************************************************/
/*
Get table map for list of Item_field
*/
static table_map get_table_map(List<Item> *items)
{
List_iterator_fast<Item> item_it(*items);
Item_field *item;
table_map map= 0;
while ((item= (Item_field *) item_it++))
map|= item->used_tables();
DBUG_PRINT("info",("table_map: 0x%08x", map));
return map;
}
/*
make update specific preparation and checks after opening tables
SYNOPSIS
mysql_multi_update_prepare()
thd thread handler
RETURN
FALSE OK
TRUE Error
*/
bool mysql_multi_update_prepare(THD *thd)
{
LEX *lex= thd->lex;
ulong opened_tables;
TABLE_LIST *table_list= lex->query_tables;
TABLE_LIST *tl, *leaves;
List<Item> *fields= &lex->select_lex.item_list;
table_map tables_for_update;
int res;
bool update_view= 0;
/*
if this multi-update was converted from usual update, here is table
counter else junk will be assigned here, but then replaced with real
count in open_tables()
*/
uint table_count= lex->table_count;
const bool using_lock_tables= thd->locked_tables != 0;
bool original_multiupdate= (thd->lex->sql_command == SQLCOM_UPDATE_MULTI);
DBUG_ENTER("mysql_multi_update_prepare");
/* following need for prepared statements, to run next time multi-update */
thd->lex->sql_command= SQLCOM_UPDATE_MULTI;
/* open tables and create derived ones, but do not lock and fill them */
if ((original_multiupdate && open_tables(thd, &table_list, & table_count)) ||
mysql_handle_derived(lex, &mysql_derived_prepare))
DBUG_RETURN(TRUE);
/*
setup_tables() need for VIEWs. JOIN::prepare() will call setup_tables()
second time, but this call will do nothing (there are check for second
call in setup_tables()).
*/
if (setup_tables(thd, table_list, &lex->select_lex.where,
&lex->select_lex.leaf_tables, FALSE))
DBUG_RETURN(TRUE);
leaves= lex->select_lex.leaf_tables;
if ((lex->select_lex.no_wrap_view_item= 1,
res= setup_fields(thd, 0, table_list, *fields, 1, 0, 0),
lex->select_lex.no_wrap_view_item= 0,
res))
DBUG_RETURN(TRUE);
for (tl= table_list; tl ; tl= tl->next_local)
{
if (tl->view)
{
update_view= 1;
break;
}
}
if (update_view && check_fields(thd, *fields))
{
DBUG_RETURN(TRUE);
}
tables_for_update= get_table_map(fields);
/*
Setup timestamp handling and locking mode
*/
for (tl= leaves; tl; tl= tl->next_leaf)
{
TABLE *table= tl->table;
/* Only set timestamp column if this is not modified */
if (table->timestamp_field &&
table->timestamp_field->query_id == thd->query_id)
table->timestamp_field_type= TIMESTAMP_NO_AUTO_SET;
/* if table will be updated then check that it is unique */
if (table->map & tables_for_update)
{
if (!tl->updatable || check_key_in_view(thd, tl))
{
my_error(ER_NON_UPDATABLE_TABLE, MYF(0), tl->alias, "UPDATE");
DBUG_RETURN(TRUE);
}
DBUG_PRINT("info",("setting table `%s` for update", tl->alias));
/*
If table will be updated we should not downgrade lock for it and
leave it as is.
*/
}
else
{
DBUG_PRINT("info",("setting table `%s` for read-only", tl->alias));
/*
If we are using the binary log, we need TL_READ_NO_INSERT to get
correct order of statements. Otherwise, we use a TL_READ lock to
improve performance.
*/
tl->lock_type= using_update_log ? TL_READ_NO_INSERT : TL_READ;
tl->updating= 0;
/* Update TABLE::lock_type accordingly. */
if (!tl->placeholder() && !tl->schema_table && !using_lock_tables)
tl->table->reginfo.lock_type= tl->lock_type;
}
}
for(tl= table_list; tl; tl= tl->next_local)
{
/* Check access privileges for table */
if (!tl->derived)
{
uint want_privilege= tl->updating ? UPDATE_ACL : SELECT_ACL;
if (check_access(thd, want_privilege,
tl->db, &tl->grant.privilege, 0, 0) ||
(grant_option && check_grant(thd, want_privilege, tl, 0, 1, 0)))
DBUG_RETURN(TRUE);
}
}
/* check single table update for view compound from several tables */
for (tl= table_list; tl; tl= tl->next_local)
{
if (tl->effective_algorithm == VIEW_ALGORITHM_MERGE)
{
TABLE_LIST *for_update= 0;
if (tl->check_single_table(&for_update, tables_for_update, tl))
{
my_error(ER_VIEW_MULTIUPDATE, MYF(0),
tl->view_db.str, tl->view_name.str);
DBUG_RETURN(-1);
}
}
}
opened_tables= thd->status_var.opened_tables;
/* now lock and fill tables */
if (lock_tables(thd, table_list, table_count))
DBUG_RETURN(TRUE);
/*
we have to re-call fixfields for fixed items, because lock maybe
reopened tables
*/
if (opened_tables != thd->status_var.opened_tables)
{
/*
Fields items cleanup(). There are only Item_fields in the list, so we
do not do Item tree walking
*/
List_iterator_fast<Item> it(*fields);
Item *item;
while ((item= it++))
item->cleanup();
/* We have to cleanup translation tables of views. */
for (TABLE_LIST *tbl= table_list; tbl; tbl= tbl->next_global)
tbl->cleanup_items();
if (setup_tables(thd, table_list, &lex->select_lex.where,
&lex->select_lex.leaf_tables, FALSE) ||
(lex->select_lex.no_wrap_view_item= 1,
res= setup_fields(thd, 0, table_list, *fields, 1, 0, 0),
lex->select_lex.no_wrap_view_item= 0,
res))
DBUG_RETURN(TRUE);
}
/*
Check that we are not using table that we are updating, but we should
skip all tables of UPDATE SELECT itself
*/
lex->select_lex.exclude_from_table_unique_test= TRUE;
/* We only need SELECT privilege for columns in the values list */
for (tl= leaves; tl; tl= tl->next_leaf)
{
TABLE *table= tl->table;
TABLE_LIST *tlist;
if (!(tlist= tl->belong_to_view ? tl->belong_to_view : tl)->derived)
{
tlist->grant.want_privilege=
(SELECT_ACL & ~tlist->grant.privilege);
table->grant.want_privilege= (SELECT_ACL & ~table->grant.privilege);
}
DBUG_PRINT("info", ("table: %s want_privilege: %u", tl->alias,
(uint) table->grant.want_privilege));
if (tl->lock_type != TL_READ &&
tl->lock_type != TL_READ_NO_INSERT &&
unique_table(tl, table_list))
{
my_error(ER_UPDATE_TABLE_USED, MYF(0), table_list->table_name);
DBUG_RETURN(TRUE);
}
}
if (thd->fill_derived_tables() &&
mysql_handle_derived(lex, &mysql_derived_filling))
DBUG_RETURN(TRUE);
DBUG_RETURN (FALSE);
}
/*
Setup multi-update handling and call SELECT to do the join
*/
bool mysql_multi_update(THD *thd,
TABLE_LIST *table_list,
List<Item> *fields,
List<Item> *values,
COND *conds,
ulong options,
enum enum_duplicates handle_duplicates, bool ignore,
SELECT_LEX_UNIT *unit, SELECT_LEX *select_lex)
{
multi_update *result;
DBUG_ENTER("mysql_multi_update");
if (mysql_multi_update_prepare(thd))
DBUG_RETURN(TRUE);
if (!(result= new multi_update(thd, table_list,
thd->lex->select_lex.leaf_tables,
fields, values,
handle_duplicates, ignore)))
DBUG_RETURN(TRUE);
thd->no_trans_update= 0;
thd->abort_on_warning= test(thd->variables.sql_mode &
(MODE_STRICT_TRANS_TABLES |
MODE_STRICT_ALL_TABLES));
List<Item> total_list;
(void) 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);
delete result;
thd->abort_on_warning= 0;
DBUG_RETURN(FALSE);
}
multi_update::multi_update(THD *thd_arg, TABLE_LIST *table_list,
TABLE_LIST *leaves_list,
List<Item> *field_list, List<Item> *value_list,
enum enum_duplicates handle_duplicates_arg,
bool ignore_arg)
:all_tables(table_list), leaves(leaves_list), update_tables(0),
thd(thd_arg), tmp_tables(0), updated(0), found(0), fields(field_list),
values(value_list), table_count(0), copy_field(0),
handle_duplicates(handle_duplicates_arg), do_update(1), trans_safe(0),
transactional_tables(1), ignore(ignore_arg)
{}
/*
Connect fields with tables and create list of tables that are updated
*/
int multi_update::prepare(List<Item> &not_used_values,
SELECT_LEX_UNIT *lex_unit)
{
TABLE_LIST *table_ref;
SQL_LIST update;
table_map tables_to_update;
Item_field *item;
List_iterator_fast<Item> field_it(*fields);
List_iterator_fast<Item> value_it(*values);
uint i, max_fields;
DBUG_ENTER("multi_update::prepare");
thd->count_cuted_fields= CHECK_FIELD_WARN;
thd->cuted_fields=0L;
thd->proc_info="updating main table";
tables_to_update= get_table_map(fields);
if (!tables_to_update)
{
my_message(ER_NO_TABLES_USED, ER(ER_NO_TABLES_USED), MYF(0));
DBUG_RETURN(1);
}
/*
We have to check values after setup_tables to get used_keys right in
reference tables
*/
if (setup_fields(thd, 0, all_tables, *values, 1, 0, 0))
DBUG_RETURN(1);
/*
Save tables beeing updated in update_tables
update_table->shared is position for table
Don't use key read on tables that are updated
*/
update.empty();
for (table_ref= leaves; table_ref; table_ref= table_ref->next_leaf)
{
/* TODO: add support of view of join support */
TABLE *table=table_ref->table;
if (tables_to_update & table->map)
{
TABLE_LIST *tl= (TABLE_LIST*) thd->memdup((char*) table_ref,
sizeof(*tl));
if (!tl)
DBUG_RETURN(1);
update.link_in_list((byte*) tl, (byte**) &tl->next_local);
tl->shared= table_count++;
table->no_keyread=1;
table->used_keys.clear_all();
table->pos_in_table_list= tl;
}
}
table_count= update.elements;
update_tables= (TABLE_LIST*) update.first;
tmp_tables = (TABLE**) thd->calloc(sizeof(TABLE *) * table_count);
tmp_table_param = (TMP_TABLE_PARAM*) thd->calloc(sizeof(TMP_TABLE_PARAM) *
table_count);
fields_for_table= (List_item **) thd->alloc(sizeof(List_item *) *
table_count);
values_for_table= (List_item **) thd->alloc(sizeof(List_item *) *
table_count);
if (thd->is_fatal_error)
DBUG_RETURN(1);
for (i=0 ; i < table_count ; i++)
{
fields_for_table[i]= new List_item;
values_for_table[i]= new List_item;
}
if (thd->is_fatal_error)
DBUG_RETURN(1);
/* Split fields into fields_for_table[] and values_by_table[] */
while ((item= (Item_field *) field_it++))
{
Item *value= value_it++;
uint offset= item->field->table->pos_in_table_list->shared;
fields_for_table[offset]->push_back(item);
values_for_table[offset]->push_back(value);
}
if (thd->is_fatal_error)
DBUG_RETURN(1);
/* Allocate copy fields */
max_fields=0;
for (i=0 ; i < table_count ; i++)
set_if_bigger(max_fields, fields_for_table[i]->elements);
copy_field= new Copy_field[max_fields];
/*
Mark all copies of tables that are updates to ensure that
init_read_record() will not try to enable a cache on them
The problem is that for queries like
UPDATE t1, t1 AS t2 SET t1.b=t2.c WHERE t1.a=t2.a;
the row buffer may contain things that doesn't match what is on disk
which will cause an error when reading a row.
(This issue is mostly relevent for MyISAM tables)
*/
for (table_ref= leaves; table_ref; table_ref= table_ref->next_leaf)
{
TABLE *table=table_ref->table;
if (!(tables_to_update & table->map) &&
find_table_in_local_list(update_tables, table_ref->db,
table_ref->table_name))
table->no_cache= 1; // Disable row cache
}
DBUG_RETURN(thd->is_fatal_error != 0);
}
/*
Initialize table for multi table
IMPLEMENTATION
- Update first table in join on the fly, if possible
- Create temporary tables to store changed values for all other tables
that are updated (and main_table if the above doesn't hold).
*/
bool
multi_update::initialize_tables(JOIN *join)
{
TABLE_LIST *table_ref;
DBUG_ENTER("initialize_tables");
if ((thd->options & OPTION_SAFE_UPDATES) && error_if_full_join(join))
DBUG_RETURN(1);
main_table=join->join_tab->table;
trans_safe= transactional_tables= main_table->file->has_transactions();
table_to_update= 0;
/* Create a temporary table for keys to all tables, except main table */
for (table_ref= update_tables; table_ref; table_ref= table_ref->next_local)
{
TABLE *table=table_ref->table;
uint cnt= table_ref->shared;
Item_field *ifield;
List<Item> temp_fields= *fields_for_table[cnt];
ORDER group;
if (table == main_table) // First table in join
{
if (safe_update_on_fly(join->join_tab, &temp_fields))
{
table_to_update= main_table; // Update table on the fly
continue;
}
}
TMP_TABLE_PARAM *tmp_param= tmp_table_param+cnt;
/*
Create a temporary table to store all fields that are changed for this
table. The first field in the temporary table is a pointer to the
original row so that we can find and update it
*/
/* ok to be on stack as this is not referenced outside of this func */
Field_string offset(table->file->ref_length, 0, "offset",
table, &my_charset_bin);
if (!(ifield= new Item_field(((Field *) &offset))))
DBUG_RETURN(1);
ifield->maybe_null= 0;
if (temp_fields.push_front(ifield))
DBUG_RETURN(1);
/* Make an unique key over the first field to avoid duplicated updates */
bzero((char*) &group, sizeof(group));
group.asc= 1;
group.item= (Item**) temp_fields.head_ref();
tmp_param->quick_group=1;
tmp_param->field_count=temp_fields.elements;
tmp_param->group_parts=1;
tmp_param->group_length= table->file->ref_length;
if (!(tmp_tables[cnt]=create_tmp_table(thd,
tmp_param,
temp_fields,
(ORDER*) &group, 0, 0,
TMP_TABLE_ALL_COLUMNS,
HA_POS_ERROR,
(char *) "")))
DBUG_RETURN(1);
tmp_tables[cnt]->file->extra(HA_EXTRA_WRITE_CACHE);
}
DBUG_RETURN(0);
}
/*
Check if table is safe to update on fly
SYNOPSIS
safe_update_on_fly
join_tab How table is used in join
fields Fields that are updated
NOTES
We can update the first table in join on the fly if we know that
a row in this table will never be read twice. This is true under
the following conditions:
- We are doing a table scan and the data is in a separate file (MyISAM) or
if we don't update a clustered key.
- We are doing a range scan and we don't update the scan key or
the primary key for a clustered table handler.
When checking for above cases we also should take into account that
BEFORE UPDATE trigger potentially may change value of any field in row
being updated.
WARNING
This code is a bit dependent of how make_join_readinfo() works.
RETURN
0 Not safe to update
1 Safe to update
*/
static bool safe_update_on_fly(JOIN_TAB *join_tab, List<Item> *fields)
{
TABLE *table= join_tab->table;
switch (join_tab->type) {
case JT_SYSTEM:
case JT_CONST:
case JT_EQ_REF:
return TRUE; // At most one matching row
case JT_REF:
case JT_REF_OR_NULL:
return !check_if_key_used(table, join_tab->ref.key, *fields) &&
!(table->triggers &&
table->triggers->has_before_update_triggers());
case JT_ALL:
/* If range search on index */
if (join_tab->quick)
return !join_tab->quick->check_if_keys_used(fields) &&
!(table->triggers &&
table->triggers->has_before_update_triggers());
/* If scanning in clustered key */
if ((table->file->table_flags() & HA_PRIMARY_KEY_IN_READ_INDEX) &&
table->s->primary_key < MAX_KEY)
return !check_if_key_used(table, table->s->primary_key, *fields) &&
!(table->triggers &&
table->triggers->has_before_update_triggers());
return TRUE;
default:
break; // Avoid compler warning
}
return FALSE;
}
multi_update::~multi_update()
{
TABLE_LIST *table;
for (table= update_tables ; table; table= table->next_local)
table->table->no_keyread= table->table->no_cache= 0;
if (tmp_tables)
{
for (uint cnt = 0; cnt < table_count; cnt++)
{
if (tmp_tables[cnt])
{
free_tmp_table(thd, tmp_tables[cnt]);
tmp_table_param[cnt].cleanup();
}
}
}
if (copy_field)
delete [] copy_field;
thd->count_cuted_fields= CHECK_FIELD_IGNORE; // Restore this setting
if (!trans_safe)
thd->options|=OPTION_STATUS_NO_TRANS_UPDATE;
}
bool multi_update::send_data(List<Item> &not_used_values)
{
TABLE_LIST *cur_table;
DBUG_ENTER("multi_update::send_data");
for (cur_table= update_tables; cur_table; cur_table= cur_table->next_local)
{
TABLE *table= cur_table->table;
/*
Check if we are using outer join and we didn't find the row
or if we have already updated this row in the previous call to this
function.
The same row may be presented here several times in a join of type
UPDATE t1 FROM t1,t2 SET t1.a=t2.a
In this case we will do the update for the first found row combination.
The join algorithm guarantees that we will not find the a row in
t1 several times.
*/
if (table->status & (STATUS_NULL_ROW | STATUS_UPDATED))
continue;
uint offset= cur_table->shared;
table->file->position(table->record[0]);
if (table == table_to_update)
{
table->status|= STATUS_UPDATED;
store_record(table,record[1]);
if (fill_record_n_invoke_before_triggers(thd, *fields_for_table[offset],
*values_for_table[offset], 0,
table->triggers,
TRG_EVENT_UPDATE))
DBUG_RETURN(1);
found++;
if (compare_record(table, thd->query_id))
{
int error;
if ((error= cur_table->view_check_option(thd, ignore)) !=
VIEW_CHECK_OK)
{
found--;
if (error == VIEW_CHECK_SKIP)
continue;
else if (error == VIEW_CHECK_ERROR)
DBUG_RETURN(1);
}
if (!updated++)
{
/*
Inform the main table that we are going to update the table even
while we may be scanning it. This will flush the read cache
if it's used.
*/
main_table->file->extra(HA_EXTRA_PREPARE_FOR_UPDATE);
}
if ((error=table->file->update_row(table->record[1],
table->record[0])))
{
updated--;
if (!ignore || error != HA_ERR_FOUND_DUPP_KEY)
{
thd->fatal_error(); // Force error message
table->file->print_error(error,MYF(0));
DBUG_RETURN(1);
}
}
else
{
if (!table->file->has_transactions())
thd->no_trans_update= 1;
if (table->triggers &&
table->triggers->process_triggers(thd, TRG_EVENT_UPDATE,
TRG_ACTION_AFTER, TRUE))
DBUG_RETURN(1);
}
}
}
else
{
int error;
TABLE *tmp_table= tmp_tables[offset];
fill_record(thd, tmp_table->field+1, *values_for_table[offset], 1);
found++;
/* Store pointer to row */
memcpy((char*) tmp_table->field[0]->ptr,
(char*) table->file->ref, table->file->ref_length);
/* Write row, ignoring duplicated updates to a row */
if ((error= tmp_table->file->write_row(tmp_table->record[0])) &&
(error != HA_ERR_FOUND_DUPP_KEY &&
error != HA_ERR_FOUND_DUPP_UNIQUE))
{
if (create_myisam_from_heap(thd, tmp_table, tmp_table_param + offset,
error, 1))
{
do_update=0;
DBUG_RETURN(1); // Not a table_is_full error
}
}
}
}
DBUG_RETURN(0);
}
void multi_update::send_error(uint errcode,const char *err)
{
/* First send error what ever it is ... */
my_error(errcode, MYF(0), err);
/* If nothing updated return */
if (!updated)
return;
/* Something already updated so we have to invalidate cache */
query_cache_invalidate3(thd, update_tables, 1);
/*
If all tables that has been updated are trans safe then just do rollback.
If not attempt to do remaining updates.
*/
if (trans_safe)
ha_rollback_stmt(thd);
else if (do_update && table_count > 1)
{
/* Add warning here */
VOID(do_updates(0));
}
}
int multi_update::do_updates(bool from_send_error)
{
TABLE_LIST *cur_table;
int local_error;
ha_rows org_updated;
TABLE *table, *tmp_table;
DBUG_ENTER("do_updates");
do_update= 0; // Don't retry this function
if (!found)
DBUG_RETURN(0);
for (cur_table= update_tables; cur_table; cur_table= cur_table->next_local)
{
byte *ref_pos;
table = cur_table->table;
if (table == table_to_update)
continue; // Already updated
org_updated= updated;
tmp_table= tmp_tables[cur_table->shared];
tmp_table->file->extra(HA_EXTRA_CACHE); // Change to read cache
(void) table->file->ha_rnd_init(0);
table->file->extra(HA_EXTRA_NO_CACHE);
/*
Setup copy functions to copy fields from temporary table
*/
List_iterator_fast<Item> field_it(*fields_for_table[cur_table->shared]);
Field **field= tmp_table->field+1; // Skip row pointer
Copy_field *copy_field_ptr= copy_field, *copy_field_end;
for ( ; *field ; field++)
{
Item_field *item= (Item_field* ) field_it++;
(copy_field_ptr++)->set(item->field, *field, 0);
}
copy_field_end=copy_field_ptr;
if ((local_error = tmp_table->file->ha_rnd_init(1)))
goto err;
ref_pos= (byte*) tmp_table->field[0]->ptr;
for (;;)
{
if (thd->killed && trans_safe)
goto err;
if ((local_error=tmp_table->file->rnd_next(tmp_table->record[0])))
{
if (local_error == HA_ERR_END_OF_FILE)
break;
if (local_error == HA_ERR_RECORD_DELETED)
continue; // May happen on dup key
goto err;
}
if ((local_error= table->file->rnd_pos(table->record[0], ref_pos)))
goto err;
table->status|= STATUS_UPDATED;
store_record(table,record[1]);
/* Copy data from temporary table to current table */
for (copy_field_ptr=copy_field;
copy_field_ptr != copy_field_end;
copy_field_ptr++)
(*copy_field_ptr->do_copy)(copy_field_ptr);
if (table->triggers &&
table->triggers->process_triggers(thd, TRG_EVENT_UPDATE,
TRG_ACTION_BEFORE, TRUE))
goto err2;
if (compare_record(table, thd->query_id))
{
if ((local_error=table->file->update_row(table->record[1],
table->record[0])))
{
if (!ignore || local_error != HA_ERR_FOUND_DUPP_KEY)
goto err;
}
updated++;
if (table->triggers &&
table->triggers->process_triggers(thd, TRG_EVENT_UPDATE,
TRG_ACTION_AFTER, TRUE))
goto err2;
}
}
if (updated != org_updated)
{
if (table->file->has_transactions())
transactional_tables= 1;
else
trans_safe= 0; // Can't do safe rollback
}
(void) table->file->ha_rnd_end();
(void) tmp_table->file->ha_rnd_end();
}
DBUG_RETURN(0);
err:
if (!from_send_error)
{
thd->fatal_error();
table->file->print_error(local_error,MYF(0));
}
err2:
(void) table->file->ha_rnd_end();
(void) tmp_table->file->ha_rnd_end();
if (updated != org_updated)
{
if (table->file->has_transactions())
transactional_tables= 1;
else
trans_safe= 0;
}
DBUG_RETURN(1);
}
/* out: 1 if error, 0 if success */
bool multi_update::send_eof()
{
char buff[STRING_BUFFER_USUAL_SIZE];
thd->proc_info="updating reference tables";
/* Does updates for the last n - 1 tables, returns 0 if ok */
int local_error = (table_count) ? do_updates(0) : 0;
thd->proc_info= "end";
/* We must invalidate the query cache before binlog writing and
ha_autocommit_... */
if (updated)
{
query_cache_invalidate3(thd, update_tables, 1);
}
/*
Write the SQL statement to the binlog if we updated
rows and we succeeded or if we updated some non
transacational tables.
Note that if we updated nothing we don't write to the binlog (TODO:
fix this).
*/
if (updated && (local_error <= 0 || !trans_safe))
{
if (mysql_bin_log.is_open())
{
if (local_error <= 0)
thd->clear_error();
Query_log_event qinfo(thd, thd->query, thd->query_length,
transactional_tables, FALSE);
if (mysql_bin_log.write(&qinfo) && trans_safe)
local_error= 1; // Rollback update
}
if (!transactional_tables)
thd->options|=OPTION_STATUS_NO_TRANS_UPDATE;
}
if (transactional_tables)
{
if (ha_autocommit_or_rollback(thd, local_error != 0))
local_error=1;
}
if (local_error > 0) // if the above log write did not fail ...
{
/* Safety: If we haven't got an error before (should not happen) */
my_message(ER_UNKNOWN_ERROR, "An error occured in multi-table update",
MYF(0));
return TRUE;
}
sprintf(buff, ER(ER_UPDATE_INFO), (ulong) found, (ulong) updated,
(ulong) thd->cuted_fields);
thd->row_count_func=
(thd->client_capabilities & CLIENT_FOUND_ROWS) ? found : updated;
::send_ok(thd, (ulong) thd->row_count_func,
thd->insert_id_used ? thd->insert_id() : 0L,buff);
return FALSE;
}
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