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bacd40f3fb0385cf205b01edeab4cecca4dedbe0
mariadb/sql/sql_update.cc
sergefp@mysql.com 56ba8abd12 Merge spetrunia@bk-internal.mysql.com:/home/bk/mysql-5.1-new 
into mysql.com:/home/psergey/mysql-5.1-ppruning-r4
2006-01-04 11:25:48 +03:00

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48 KiB
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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;
Name_resolution_context *context= &thd->lex->select_lex.context;
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, will_batch;
int res;
int error, loc_error;
uint used_index= MAX_KEY, dup_key_found;
bool need_sort= TRUE;
#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;
bool need_reopen;
DBUG_ENTER("mysql_update");
LINT_INIT(timestamp_query_id);
for ( ; ; )
{
if (open_tables(thd, &table_list, &table_count, 0))
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 */
DBUG_RETURN(2);
}
if (!lock_tables(thd, table_list, table_count, &need_reopen))
break;
if (!need_reopen)
DBUG_RETURN(1);
close_tables_for_reopen(thd, table_list);
}
if (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;
table_list->register_want_access(want_privilege);
#endif
/*
Indicate that the set of fields is to be updated by passing 2 for
set_query_id.
*/
if (setup_fields_with_no_wrap(thd, 0, fields, 2, 0, 0))
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;
table->file->ha_set_bit_in_write_set(table->timestamp_field->fieldnr);
}
}
#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, values, 1, 0, 0))
{
free_underlaid_joins(thd, select_lex);
DBUG_RETURN(1); /* purecov: inspected */
}
if (conds)
{
Item::cond_result cond_value;
conds= remove_eq_conds(thd, conds, &cond_value);
if (cond_value == Item::COND_FALSE)
limit= 0; // Impossible WHERE
}
// 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 || !limit ||
(select && select->check_quick(thd, safe_update, 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 (!select && limit != HA_POS_ERROR)
{
if ((used_index= get_index_for_order(table, order, limit)) != MAX_KEY)
need_sort= FALSE;
}
/* 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
{
used_key_is_modified= 0;
if (used_index == MAX_KEY) // no index for sort order
used_index= table->file->key_used_on_scan;
if (used_index != MAX_KEY)
used_key_is_modified= check_if_key_used(table, used_index, fields);
}
#ifdef WITH_PARTITION_STORAGE_ENGINE
if (used_key_is_modified || order ||
partition_key_modified(table, fields))
#else
if (used_key_is_modified || order)
#endif
{
/*
We can't update table directly; We must first search after all
matching rows before updating the table!
*/
table->file->ha_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);
}
/* note: can actually avoid sorting below.. */
if (order && (need_sort || used_key_is_modified))
{
/*
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;
used_index= MAX_KEY; // For call to init_read_record()
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;
table->file->try_semi_consistent_read(1);
if (used_index == MAX_KEY || (select && select->quick))
init_read_record(&info,thd,table,select,0,1);
else
init_read_record_idx(&info, thd, table, 1, used_index);
thd->proc_info="Searching rows for update";
uint tmp_limit= limit;
while (!(error=info.read_record(&info)) && !thd->killed)
{
if (!(select && select->skip_record()))
{
if (table->file->was_semi_consistent_read())
continue; /* repeat the read of the same row if it still exists */
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;
}
}
else
table->file->unlock_row();
}
if (thd->killed && !error)
error= 1; // Aborted
limit= tmp_limit;
table->file->try_semi_consistent_read(0);
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;
table->file->try_semi_consistent_read(1);
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)));
will_batch= !table->file->start_bulk_update();
while (!(error=info.read_record(&info)) && !thd->killed)
{
if (!(select && select->skip_record()))
{
if (table->file->was_semi_consistent_read())
continue; /* repeat the read of the same row if it still exists */
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 (will_batch)
{
/*
Typically a batched handler can execute the batched jobs when:
1) When specifically told to do so
2) When it is not a good idea to batch anymore
3) When it is necessary to send batch for other reasons
(One such reason is when READ's must be performed)
1) is covered by exec_bulk_update calls.
2) and 3) is handled by the bulk_update_row method.
bulk_update_row can execute the updates including the one
defined in the bulk_update_row or not including the row
in the call. This is up to the handler implementation and can
vary from call to call.
The dup_key_found reports the number of duplicate keys found
in those updates actually executed. It only reports those if
the extra call with HA_EXTRA_IGNORE_DUP_KEY have been issued.
If this hasn't been issued it returns an error code and can
ignore this number. Thus any handler that implements batching
for UPDATE IGNORE must also handle this extra call properly.
If a duplicate key is found on the record included in this
call then it should be included in the count of dup_key_found
and error should be set to 0 (only if these errors are ignored).
*/
error= table->file->bulk_update_row(table->record[1],
table->record[0],
&dup_key_found);
limit+= dup_key_found;
updated-= dup_key_found;
}
else
{
/* Non-batched update */
error= table->file->ha_update_row((byte*) table->record[1],
(byte*) table->record[0]);
}
if (!error)
{
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)
{
/*
If (ignore && error == HA_ERR_FOUND_DUPP_KEY) we don't have to
do anything; otherwise...
*/
if (error != HA_ERR_FOUND_DUPP_KEY)
thd->fatal_error(); /* Other handler errors are fatal */
table->file->print_error(error,MYF(0));
error= 1;
break;
}
}
if (!--limit && using_limit)
{
/*
We have reached end-of-file in most common situations where no
batching has occurred and if batching was supposed to occur but
no updates were made and finally when the batch execution was
performed without error and without finding any duplicate keys.
If the batched updates were performed with errors we need to
check and if no error but duplicate key's found we need to
continue since those are not counted for in limit.
*/
if (will_batch &&
((error= table->file->exec_bulk_update(&dup_key_found)) ||
!dup_key_found))
{
if (error)
{
/*
The handler should not report error of duplicate keys if they
are ignored. This is a requirement on batching handlers.
*/
table->file->print_error(error,MYF(0));
error= 1;
break;
}
/*
Either an error was found and we are ignoring errors or there
were duplicate keys found. In both cases we need to correct
the counters and continue the loop.
*/
limit= dup_key_found; //limit is 0 when we get here so need to +
updated-= dup_key_found;
}
else
{
error= -1; // Simulate end of file
break;
}
}
}
else
table->file->unlock_row();
thd->row_count++;
}
dup_key_found= 0;
if (thd->killed && !error)
error= 1; // Aborted
else if (will_batch &&
(loc_error= table->file->exec_bulk_update(&dup_key_found)))
/*
An error has occurred when a batched update was performed and returned
an error indication. It cannot be an allowed duplicate key error since
we require the batching handler to treat this as a normal behavior.
Otherwise we simply remove the number of duplicate keys records found
in the batched update.
*/
{
thd->fatal_error();
table->file->print_error(loc_error,MYF(0));
error= 1;
}
else
updated-= dup_key_found;
if (will_batch)
table->file->end_bulk_update();
table->file->try_semi_consistent_read(0);
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);
}
/*
error < 0 means really no error at all: we processed all rows until the
last one without error. error > 0 means an error (e.g. unique key
violation and no IGNORE or REPLACE). error == 0 is also an error (if
preparing the record or invoking before triggers fails). See
ha_autocommit_or_rollback(error>=0) and DBUG_RETURN(error>=0) below.
Sometimes we want to binlog even if we updated no rows, in case user used
it to be sure master and slave are in same state.
*/
if ((error < 0) || (updated && !transactional_table))
{
if (mysql_bin_log.is_open())
{
if (error < 0)
thd->clear_error();
if (thd->binlog_query(THD::ROW_QUERY_TYPE,
thd->query, thd->query_length,
transactional_table, FALSE) &&
transactional_table)
{
error=1; // Rollback update
}
}
if (!transactional_table)
thd->options|=OPTION_STATUS_NO_TRANS_UPDATE;
}
free_underlaid_joins(thd, select_lex);
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;
}
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);
table_list->register_want_access(SELECT_ACL);
#endif
bzero((char*) &tables,sizeof(tables)); // For ORDER BY
tables.table= table;
tables.alias= table_list->alias;
thd->lex->allow_sum_func= 0;
if (setup_tables(thd, &select_lex->context, &select_lex->top_join_list,
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 */
{
TABLE_LIST *duplicate;
if ((duplicate= unique_table(thd, table_list, table_list->next_global)))
{
update_non_unique_table_error(table_list, "UPDATE", duplicate);
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;
TABLE_LIST *table_list= lex->query_tables;
TABLE_LIST *tl, *leaves;
List<Item> *fields= &lex->select_lex.item_list;
table_map tables_for_update;
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);
bool need_reopen= FALSE;
DBUG_ENTER("mysql_multi_update_prepare");
/* following need for prepared statements, to run next time multi-update */
thd->lex->sql_command= SQLCOM_UPDATE_MULTI;
reopen_tables:
/* open tables and create derived ones, but do not lock and fill them */
if (((original_multiupdate || need_reopen) &&
open_tables(thd, &table_list, &table_count, 0)) ||
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, &lex->select_lex.context,
&lex->select_lex.top_join_list,
table_list, &lex->select_lex.where,
&lex->select_lex.leaf_tables, FALSE))
DBUG_RETURN(TRUE);
if (setup_fields_with_no_wrap(thd, 0, *fields, 2, 0, 0))
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
*/
leaves= lex->select_lex.leaf_tables;
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,
test(tl->schema_table)) ||
(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);
}
}
}
/* now lock and fill tables */
if (lock_tables(thd, table_list, table_count, &need_reopen))
{
if (!need_reopen)
DBUG_RETURN(TRUE);
/*
We have to reopen tables since some of them were altered or dropped
during lock_tables() or something was done with their triggers.
Let us do some cleanups to be able do setup_table() and setup_fields()
once again.
*/
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();
close_tables_for_reopen(thd, table_list);
goto reopen_tables;
}
/*
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->top_table())->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)
{
TABLE_LIST *duplicate;
if ((duplicate= unique_table(thd, tl, table_list)))
{
update_non_unique_table_error(table_list, "UPDATE", duplicate);
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,
ulonglong 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 (!(result= new multi_update(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(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),
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, *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) &&
unique_table(thd, table_ref, update_tables))
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",
&my_charset_bin);
offset.init(table);
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->ha_update_row(table->record[1],
table->record[0])))
{
updated--;
if (!ignore || error != HA_ERR_FOUND_DUPP_KEY)
{
/*
If (ignore && error == HA_ERR_FOUND_DUPP_KEY) we don't have to
do anything; otherwise...
*/
if (error != HA_ERR_FOUND_DUPP_KEY)
thd->fatal_error(); /* Other handler errors are fatal */
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);
/* 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->ha_write_row(tmp_table->record[0])))
{
if (error != HA_ERR_FOUND_DUPP_KEY &&
error != HA_ERR_FOUND_DUPP_UNIQUE &&
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
}
}
else
found++;
}
}
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->ha_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
transactional tables.
*/
if ((local_error == 0) || (updated && !trans_safe))
{
if (mysql_bin_log.is_open())
{
if (local_error == 0)
thd->clear_error();
if (thd->binlog_query(THD::ROW_QUERY_TYPE,
thd->query, thd->query_length,
transactional_tables, FALSE) &&
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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