WL#1266 "Separate auto-set logic from TIMESTAMP type."

Final version of patch.

Adds support for specifying of DEFAULT NOW() and/or ON UPDATE NOW()
clauses for TIMESTAMP field definition.
Current implementation allows only one such field per table and
uses several unireg types for storing info about this properties of
field. It should be replaced with better implementation when new
.frm format is introduced.

include/mysqld_error.h

@@ -309,4 +309,6 @@
 #define ER_OPTION_PREVENTS_STATEMENT 1290
 #define ER_DUPLICATED_VALUE_IN_TYPE 1291
 #define ER_TRUNCATED_WRONG_VALUE 1292
-#define ER_ERROR_MESSAGES 293
+#define ER_TOO_MUCH_AUTO_TIMESTAMP_COLS 1293
+#define ER_INVALID_ON_UPDATE 1294
+#define ER_ERROR_MESSAGES 295

mysql-test/r/create.result

@@ -44,6 +44,12 @@ create table `aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
 ERROR 42000: Incorrect table name 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'
 create table a (`aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa` int);
 ERROR 42000: Identifier name 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa' is too long
+create table test (a datetime default now());
+ERROR 42000: Invalid default value for 'a'
+create table test (a datetime on update now());
+ERROR HY000: Invalid ON UPDATE clause for 'a' field
+create table test (a int default 100 auto_increment);
+ERROR 42000: Invalid default value for 'a'
 create table 1ea10 (1a20 int,1e int);
 insert into 1ea10 values(1,1);
 select 1ea10.1a20,1e+ 1e+10 from 1ea10;

mysql-test/r/show_check.result

@@ -225,7 +225,7 @@ t1	CREATE TABLE `t1` (
   `empty_char` char(0) default NULL,
   `type_char` char(2) default NULL,
   `type_varchar` varchar(10) default NULL,
-  `type_timestamp` timestamp NOT NULL,
+  `type_timestamp` timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
   `type_date` date NOT NULL default '0000-00-00',
   `type_time` time NOT NULL default '00:00:00',
   `type_datetime` datetime NOT NULL default '0000-00-00 00:00:00',

mysql-test/r/system_mysql_db.result

@@ -103,7 +103,7 @@ tables_priv	CREATE TABLE `tables_priv` (
   `User` char(16) character set latin1 collate latin1_bin NOT NULL default '',
   `Table_name` char(64) character set latin1 collate latin1_bin NOT NULL default '',
   `Grantor` char(77) NOT NULL default '',
-  `Timestamp` timestamp NOT NULL,
+  `Timestamp` timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
   `Table_priv` set('Select','Insert','Update','Delete','Create','Drop','Grant','References','Index','Alter') NOT NULL default '',
   `Column_priv` set('Select','Insert','Update','References') NOT NULL default '',
   PRIMARY KEY  (`Host`,`Db`,`User`,`Table_name`),
@@ -117,7 +117,7 @@ columns_priv	CREATE TABLE `columns_priv` (
   `User` char(16) character set latin1 collate latin1_bin NOT NULL default '',
   `Table_name` char(64) character set latin1 collate latin1_bin NOT NULL default '',
   `Column_name` char(64) character set latin1 collate latin1_bin NOT NULL default '',
-  `Timestamp` timestamp NOT NULL,
+  `Timestamp` timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
   `Column_priv` set('Select','Insert','Update','References') NOT NULL default '',
   PRIMARY KEY  (`Host`,`Db`,`User`,`Table_name`,`Column_name`)
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1 COMMENT='Column privileges'

mysql-test/r/type_ranges.result

@@ -54,7 +54,7 @@ ushort	smallint(5) unsigned zerofill	NULL		MUL	00000		select,insert,update,refer
 umedium	mediumint(8) unsigned	NULL		MUL	0		select,insert,update,references	
 ulong	int(11) unsigned	NULL		MUL	0		select,insert,update,references	
 ulonglong	bigint(13) unsigned	NULL		MUL	0		select,insert,update,references	
-time_stamp	timestamp	NULL	YES		NULL		select,insert,update,references	
+time_stamp	timestamp	NULL	YES		CURRENT_TIMESTAMP		select,insert,update,references	
 date_field	date	NULL	YES		NULL		select,insert,update,references	
 time_field	time	NULL	YES		NULL		select,insert,update,references	
 date_time	datetime	NULL	YES		NULL		select,insert,update,references	
@@ -222,7 +222,7 @@ ushort	smallint(5) unsigned zerofill	NULL			00000		select,insert,update,referenc
 umedium	mediumint(8) unsigned	NULL		MUL	0		select,insert,update,references	
 ulong	int(11) unsigned	NULL		MUL	0		select,insert,update,references	
 ulonglong	bigint(13) unsigned	NULL		MUL	0		select,insert,update,references	
-time_stamp	timestamp	NULL	YES		NULL		select,insert,update,references	
+time_stamp	timestamp	NULL	YES		CURRENT_TIMESTAMP		select,insert,update,references	
 date_field	varchar(10)	latin1_swedish_ci	YES		NULL		select,insert,update,references	
 time_field	time	NULL	YES		NULL		select,insert,update,references	
 date_time	datetime	NULL	YES		NULL		select,insert,update,references	
@@ -248,7 +248,7 @@ ushort	smallint(5) unsigned zerofill	NULL			00000		select,insert,update,referenc
 umedium	mediumint(8) unsigned	NULL			0		select,insert,update,references	
 ulong	int(11) unsigned	NULL			0		select,insert,update,references	
 ulonglong	bigint(13) unsigned	NULL			0		select,insert,update,references	
-time_stamp	timestamp	NULL	YES		NULL		select,insert,update,references	
+time_stamp	timestamp	NULL	YES		0000-00-00 00:00:00		select,insert,update,references	
 date_field	varchar(10)	latin1_swedish_ci	YES		NULL		select,insert,update,references	
 time_field	time	NULL	YES		NULL		select,insert,update,references	
 date_time	datetime	NULL	YES		NULL		select,insert,update,references	

mysql-test/r/type_timestamp.result

@@ -128,48 +128,206 @@ t2	t4	t6	t8	t10	t12	t14
 0000-00-00 00:00:00	0000-00-00 00:00:00	0000-00-00 00:00:00	0000-00-00 00:00:00	0000-00-00 00:00:00	0000-00-00 00:00:00	0000-00-00 00:00:00
 1997-12-31 23:47:59	1997-12-31 23:47:59	1997-12-31 23:47:59	1997-12-31 23:47:59	1997-12-31 23:47:59	1997-12-31 23:47:59	1997-12-31 23:47:59
 drop table t1;
-create table t1 (t1 timestamp default '2003-01-01 00:00:00', 
+create table t1 (t1 timestamp, t2 timestamp default now());
-t2 timestamp default '2003-01-01 00:00:00');
+ERROR HY000: Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause
-set TIMESTAMP=1000000000;
+create table t1 (t1 timestamp, t2 timestamp on update now());
-insert into t1 values();
+ERROR HY000: Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause
+create table t1 (t1 timestamp, t2 timestamp default now() on update now());
+ERROR HY000: Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause
+create table t1 (t1 timestamp default now(), t2 timestamp on update now());
+ERROR HY000: Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause
+create table t1 (t1 timestamp on update now(), t2 timestamp default now() on update now());
+ERROR HY000: Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause
+create table t1 (t1 timestamp default '2003-01-01 00:00:00', t2 datetime, t3 timestamp);
+SET TIMESTAMP=1000000000;
+insert into t1 values ();
+SET TIMESTAMP=1000000001;
+update t1 set t2=now();
+SET TIMESTAMP=1000000002;
+insert into t1 (t1,t3) values (default, default);
 select * from t1;
-t1	t2
+t1	t2	t3
-2001-09-09 04:46:40	2003-01-01 00:00:00
+2003-01-01 00:00:00	2001-09-09 04:46:41	0000-00-00 00:00:00
+2003-01-01 00:00:00	NULL	0000-00-00 00:00:00
 show create table t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `t1` timestamp NOT NULL,
+  `t1` timestamp NOT NULL default '2003-01-01 00:00:00',
-  `t2` timestamp NOT NULL default '2003-01-01 00:00:00'
+  `t2` datetime default NULL,
+  `t3` timestamp NOT NULL default '0000-00-00 00:00:00'
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 show columns from t1;
 Field	Type	Null	Key	Default	Extra
-t1	timestamp	YES		NULL	
+t1	timestamp	YES		2003-01-01 00:00:00	
-t2	timestamp	YES		2003-01-01 00:00:00	
+t2	datetime	YES		NULL	
-show columns from t1 like 't2';
+t3	timestamp	YES		0000-00-00 00:00:00	
-Field	Type	Null	Key	Default	Extra
+drop table t1;
-t2	timestamp	YES		2003-01-01 00:00:00	
+create table t1 (t1 timestamp default now(), t2 datetime, t3 timestamp);
-create table t2 (select * from t1);
+SET TIMESTAMP=1000000002;
-show create table t2;
+insert into t1 values ();
-Table	Create Table
+SET TIMESTAMP=1000000003;
-t2	CREATE TABLE `t2` (
+update t1 set t2=now();
-  `t1` timestamp NOT NULL,
+SET TIMESTAMP=1000000003;
-  `t2` timestamp NOT NULL default '2003-01-01 00:00:00'
+insert into t1 (t1,t3) values (default, default);
-) ENGINE=MyISAM DEFAULT CHARSET=latin1
+select * from t1;
-alter table t1 add column t0 timestamp first;
+t1	t2	t3
+2001-09-09 04:46:42	2001-09-09 04:46:43	0000-00-00 00:00:00
+2001-09-09 04:46:43	NULL	0000-00-00 00:00:00
 show create table t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `t0` timestamp NOT NULL,
+  `t1` timestamp NOT NULL default CURRENT_TIMESTAMP,
-  `t1` timestamp NOT NULL default '2003-01-01 00:00:00',
+  `t2` datetime default NULL,
-  `t2` timestamp NOT NULL default '2003-01-01 00:00:00'
+  `t3` timestamp NOT NULL default '0000-00-00 00:00:00'
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
-drop table t1,t2;
+show columns from t1;
-create table t1 (ts1 timestamp, ts2 timestamp);
+Field	Type	Null	Key	Default	Extra
-set TIMESTAMP=1000000000;
+t1	timestamp	YES		CURRENT_TIMESTAMP	
-insert into t1 values ();
+t2	datetime	YES		NULL	
-insert into t1 values (DEFAULT, DEFAULT);
+t3	timestamp	YES		0000-00-00 00:00:00	
-select * from t1;
+drop table t1;
-ts1	ts2
+create table t1 (t1 timestamp default '2003-01-01 00:00:00' on update now(), t2 datetime);
-2001-09-09 04:46:40	0000-00-00 00:00:00
+SET TIMESTAMP=1000000004;
-2001-09-09 04:46:40	0000-00-00 00:00:00
+insert into t1 values ();
+select * from t1;
+t1	t2
+2003-01-01 00:00:00	NULL
+SET TIMESTAMP=1000000005;
+update t1 set t2=now();
+SET TIMESTAMP=1000000005;
+insert into t1 (t1) values (default);
+select * from t1;
+t1	t2
+2001-09-09 04:46:45	2001-09-09 04:46:45
+2003-01-01 00:00:00	NULL
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `t1` timestamp NOT NULL default '2003-01-01 00:00:00' on update CURRENT_TIMESTAMP,
+  `t2` datetime default NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+show columns from t1;
+Field	Type	Null	Key	Default	Extra
+t1	timestamp	YES		2003-01-01 00:00:00	
+t2	datetime	YES		NULL	
+drop table t1;
+create table t1 (t1 timestamp default now() on update now(), t2 datetime);
+SET TIMESTAMP=1000000006;
+insert into t1 values ();
+select * from t1;
+t1	t2
+2001-09-09 04:46:46	NULL
+SET TIMESTAMP=1000000007;
+update t1 set t2=now();
+SET TIMESTAMP=1000000007;
+insert into t1 (t1) values (default);
+select * from t1;
+t1	t2
+2001-09-09 04:46:47	2001-09-09 04:46:47
+2001-09-09 04:46:47	NULL
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `t1` timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
+  `t2` datetime default NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+show columns from t1;
+Field	Type	Null	Key	Default	Extra
+t1	timestamp	YES		CURRENT_TIMESTAMP	
+t2	datetime	YES		NULL	
+drop table t1;
+create table t1 (t1 timestamp, t2 datetime, t3 timestamp);
+SET TIMESTAMP=1000000007;
+insert into t1 values ();
+select * from t1;
+t1	t2	t3
+2001-09-09 04:46:47	NULL	0000-00-00 00:00:00
+SET TIMESTAMP=1000000008;
+update t1 set t2=now();
+SET TIMESTAMP=1000000008;
+insert into t1 (t1,t3) values (default, default);
+select * from t1;
+t1	t2	t3
+2001-09-09 04:46:48	2001-09-09 04:46:48	0000-00-00 00:00:00
+2001-09-09 04:46:48	NULL	0000-00-00 00:00:00
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `t1` timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
+  `t2` datetime default NULL,
+  `t3` timestamp NOT NULL default '0000-00-00 00:00:00'
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+show columns from t1;
+Field	Type	Null	Key	Default	Extra
+t1	timestamp	YES		CURRENT_TIMESTAMP	
+t2	datetime	YES		NULL	
+t3	timestamp	YES		0000-00-00 00:00:00	
+drop table t1;
+create table t1 (t1 timestamp default current_timestamp on update current_timestamp, t2 datetime);
+SET TIMESTAMP=1000000009;
+insert into t1 values ();
+select * from t1;
+t1	t2
+2001-09-09 04:46:49	NULL
+SET TIMESTAMP=1000000010;
+update t1 set t2=now();
+SET TIMESTAMP=1000000011;
+insert into t1 (t1) values (default);
+select * from t1;
+t1	t2
+2001-09-09 04:46:50	2001-09-09 04:46:50
+2001-09-09 04:46:51	NULL
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `t1` timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
+  `t2` datetime default NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+show columns from t1;
+Field	Type	Null	Key	Default	Extra
+t1	timestamp	YES		CURRENT_TIMESTAMP	
+t2	datetime	YES		NULL	
+delete from t1;
+insert into t1 values ('2004-04-01 00:00:00', '2004-04-01 00:00:00');
+SET TIMESTAMP=1000000012;
+update t1 set t1= '2004-04-02 00:00:00';
+select * from t1;
+t1	t2
+2004-04-02 00:00:00	2004-04-01 00:00:00
+update t1 as ta, t1 as tb set tb.t1= '2004-04-03 00:00:00';
+select * from t1;
+t1	t2
+2004-04-03 00:00:00	2004-04-01 00:00:00
+drop table t1;
+create table t1 (pk int primary key, t1 timestamp default current_timestamp on update current_timestamp, bulk int);
+insert into t1 values (1, '2004-04-01 00:00:00', 10);
+SET TIMESTAMP=1000000013;
+replace into t1 set pk = 1, bulk= 20;
+select * from t1;
+pk	t1	bulk
+1	2001-09-09 04:46:53	20
+drop table t1;
+create table t1 (pk int primary key, t1 timestamp default '2003-01-01 00:00:00' on update current_timestamp, bulk int);
+insert into t1 values (1, '2004-04-01 00:00:00', 10);
+SET TIMESTAMP=1000000014;
+replace into t1 set pk = 1, bulk= 20;
+select * from t1;
+pk	t1	bulk
+1	2003-01-01 00:00:00	20
+drop table t1;
+create table t1 (pk int primary key, t1 timestamp default current_timestamp, bulk int);
+insert into t1 values (1, '2004-04-01 00:00:00', 10);
+SET TIMESTAMP=1000000015;
+replace into t1 set pk = 1, bulk= 20;
+select * from t1;
+pk	t1	bulk
+1	2001-09-09 04:46:55	20
+drop table t1;
+create table t1 (t1 timestamp default current_timestamp on update current_timestamp);
+insert into t1 values ('2004-04-01 00:00:00');
+SET TIMESTAMP=1000000016;
+alter table t1 add i int default 10;
+select * from t1;
+t1	i
+2004-04-01 00:00:00	10
 drop table t1;

mysql-test/t/create.test

@@ -48,6 +48,16 @@ create table `aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
 --error 1059
 create table a (`aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa` int);
 
+#
+# Some wrong defaults, so these creates should fail too
+#
+--error 1067
+create table test (a datetime default now());
+--error 1294
+create table test (a datetime on update now());
+--error 1067
+create table test (a int default 100 auto_increment);
+
 #
 # test of dummy table names
 #

mysql-test/t/type_timestamp.test

@@ -76,35 +76,146 @@ select * from t1;
 drop table t1;
 
 #
-# Bug #1885, bug #2539. 
+# Test for TIMESTAMP column with default now() and on update now() clauses
-# Not perfect but still sensible attitude towards defaults for TIMESTAMP
-# We will ignore default value for first TIMESTAMP column.
 #
-create table t1 (t1 timestamp default '2003-01-01 00:00:00', 
+
-                 t2 timestamp default '2003-01-01 00:00:00');
+# These statements should fail.
-set TIMESTAMP=1000000000;
+--error 1293
-insert into t1 values();
+create table t1 (t1 timestamp, t2 timestamp default now());
+--error 1293
+create table t1 (t1 timestamp, t2 timestamp on update now());
+--error 1293
+create table t1 (t1 timestamp, t2 timestamp default now() on update now());
+--error 1293
+create table t1 (t1 timestamp default now(), t2 timestamp on update now());
+--error 1293
+create table t1 (t1 timestamp on update now(), t2 timestamp default now() on update now());
+
+# Let us test TIMESTAMP auto-update behaviour
+# Also we will test behaviour of TIMESTAMP field in SHOW CREATE TABLE and
+# behaviour of DEFAULT literal for such fields
+create table t1 (t1 timestamp default '2003-01-01 00:00:00', t2 datetime, t3 timestamp);
+SET TIMESTAMP=1000000000;
+insert into t1 values ();
+SET TIMESTAMP=1000000001;
+update t1 set t2=now();
+SET TIMESTAMP=1000000002;
+insert into t1 (t1,t3) values (default, default);
 select * from t1;
 show create table t1;
 show columns from t1;
-show columns from t1 like 't2';
+drop table t1;
-create table t2 (select * from t1);
-show create table t2;
 
-# Ugly, but we can't do anything about this in 4.0
+create table t1 (t1 timestamp default now(), t2 datetime, t3 timestamp);
-alter table t1 add column t0 timestamp first;
+SET TIMESTAMP=1000000002;
-show create table t1;
-
-drop table t1,t2;
-
-#
-# Test for bug 2464, DEFAULT keyword in INSERT statement should return
-# default value for column.
-#
-
-create table t1 (ts1 timestamp, ts2 timestamp);
-set TIMESTAMP=1000000000;
 insert into t1 values ();
-insert into t1 values (DEFAULT, DEFAULT);
+SET TIMESTAMP=1000000003;
+update t1 set t2=now();
+SET TIMESTAMP=1000000003;
+insert into t1 (t1,t3) values (default, default);
+select * from t1;
+show create table t1;
+show columns from t1;
+drop table t1;
+
+create table t1 (t1 timestamp default '2003-01-01 00:00:00' on update now(), t2 datetime);
+SET TIMESTAMP=1000000004;
+insert into t1 values ();
+select * from t1;
+SET TIMESTAMP=1000000005;
+update t1 set t2=now();
+SET TIMESTAMP=1000000005;
+insert into t1 (t1) values (default);
+select * from t1;
+show create table t1;
+show columns from t1;
+drop table t1;
+
+create table t1 (t1 timestamp default now() on update now(), t2 datetime);
+SET TIMESTAMP=1000000006;
+insert into t1 values ();
+select * from t1;
+SET TIMESTAMP=1000000007;
+update t1 set t2=now();
+SET TIMESTAMP=1000000007;
+insert into t1 (t1) values (default);
+select * from t1;
+show create table t1;
+show columns from t1;
+drop table t1;
+
+create table t1 (t1 timestamp, t2 datetime, t3 timestamp);
+SET TIMESTAMP=1000000007;
+insert into t1 values ();
+select * from t1;
+SET TIMESTAMP=1000000008;
+update t1 set t2=now();
+SET TIMESTAMP=1000000008;
+insert into t1 (t1,t3) values (default, default);
+select * from t1;
+show create table t1;
+show columns from t1;
+drop table t1;
+
+# Let us test if CURRENT_TIMESTAMP also works well as default value
+# (Of course NOW and CURRENT_TIMESTAMP are same for parser but still just
+# for demonstartion.)
+create table t1 (t1 timestamp default current_timestamp on update current_timestamp, t2 datetime);
+SET TIMESTAMP=1000000009;
+insert into t1 values ();
+select * from t1;
+SET TIMESTAMP=1000000010;
+update t1 set t2=now();
+SET TIMESTAMP=1000000011;
+insert into t1 (t1) values (default);
+select * from t1;
+show create table t1;
+show columns from t1;
+delete from t1;
+
+# 
+# Let us test some cases when auto-set should be disabled or influence
+# on server behavior in some other way.
+#
+
+# Update statement that explicitly sets field should not auto-set it. 
+insert into t1 values ('2004-04-01 00:00:00', '2004-04-01 00:00:00');
+SET TIMESTAMP=1000000012;
+update t1 set t1= '2004-04-02 00:00:00';
+select * from t1;
+# The same for multi updates
+update t1 as ta, t1 as tb set tb.t1= '2004-04-03 00:00:00';
 select * from t1;
 drop table t1;
+
+# Now let us test replace it should behave exactly like delete+insert
+# Case where optimization is possible DEFAULT = ON UPDATE
+create table t1 (pk int primary key, t1 timestamp default current_timestamp on update current_timestamp, bulk int);
+insert into t1 values (1, '2004-04-01 00:00:00', 10);
+SET TIMESTAMP=1000000013;
+replace into t1 set pk = 1, bulk= 20; 
+select * from t1;
+drop table t1;
+# Case in which there should not be optimisation
+create table t1 (pk int primary key, t1 timestamp default '2003-01-01 00:00:00' on update current_timestamp, bulk int);
+insert into t1 values (1, '2004-04-01 00:00:00', 10);
+SET TIMESTAMP=1000000014;
+replace into t1 set pk = 1, bulk= 20; 
+select * from t1;
+drop table t1;
+# Other similar case
+create table t1 (pk int primary key, t1 timestamp default current_timestamp, bulk int);
+insert into t1 values (1, '2004-04-01 00:00:00', 10);
+SET TIMESTAMP=1000000015;
+replace into t1 set pk = 1, bulk= 20; 
+select * from t1;
+drop table t1;
+
+# Let us test alter now
+create table t1 (t1 timestamp default current_timestamp on update current_timestamp);
+insert into t1 values ('2004-04-01 00:00:00');
+SET TIMESTAMP=1000000016;
+alter table t1 add i int default 10;
+select * from t1;
+drop table t1;
+

sql/field.cc

@@ -2842,11 +2842,50 @@ void Field_double::sql_type(String &res) const
 }
 
 
-/****************************************************************************
+/*
-** timestamp
+  TIMESTAMP type.
-** The first timestamp in the table is automaticly updated
+  Holds datetime values in range from 1970-01-01 00:00:01 UTC to 
-** by handler.cc.  The form->timestamp points at the automatic timestamp.
+  2038-01-01 00:00:00 UTC stored as number of seconds since Unix 
-****************************************************************************/
+  Epoch in UTC.
+  
+  Up to one of timestamps columns in the table can be automatically 
+  set on row update and/or have NOW() as default value.
+  TABLE::timestamp_field points to Field object for such timestamp with 
+  auto-set-on-update. TABLE::time_stamp holds offset in record + 1 for this
+  field, and is used by handler code which performs updates required.
+  
+  Actually SQL-99 says that we should allow niladic functions (like NOW())
+  as defaults for any field. Current limitations (only NOW() and only 
+  for one TIMESTAMP field) are because of restricted binary .frm format 
+  and should go away in the future.
+  
+  Also because of this limitation of binary .frm format we use 5 different
+  unireg_check values with TIMESTAMP field to distinguish various cases of
+  DEFAULT or ON UPDATE values. These values are:
+  
+  TIMESTAMP_OLD_FIELD - old timestamp, if there was not any fields with
+    auto-set-on-update (or now() as default) in this table before, then this 
+    field has NOW() as default and is updated when row changes, else it is 
+    field which has 0 as default value and is not automaitcally updated.
+  TIMESTAMP_DN_FIELD - field with NOW() as default but not set on update
+    automatically (TIMESTAMP DEFAULT NOW())
+  TIMESTAMP_UN_FIELD - field which is set on update automatically but has not 
+    NOW() as default (but it may has 0 or some other const timestamp as 
+    default) (TIMESTAMP ON UPDATE NOW()).
+  TIMESTAMP_DNUN_FIELD - field which has now() as default and is auto-set on 
+    update. (TIMESTAMP DEFAULT NOW() ON UPDATE NOW())
+  NONE - field which is not auto-set on update with some other than NOW() 
+    default value (TIMESTAMP DEFAULT 0).
+
+  Note that TIMESTAMP_OLD_FIELD's are never created explicitly now, they are 
+  left only for preserving ability to read old tables. Such fields replaced 
+  with their newer analogs in CREATE TABLE and in SHOW CREATE TABLE. This is 
+  because we want to prefer NONE unireg_check before TIMESTAMP_OLD_FIELD for 
+  "TIMESTAMP DEFAULT 'Const'" field. (Old timestamps allowed such 
+  specification too but ignored default value for first timestamp, which of 
+  course is non-standard.) In most cases user won't notice any change, only
+  exception is different behavior of old/new timestamps during ALTER TABLE.
+ */
 
 Field_timestamp::Field_timestamp(char *ptr_arg, uint32 len_arg,
 				 enum utype unireg_check_arg,
@@ -2857,15 +2896,37 @@ Field_timestamp::Field_timestamp(char *ptr_arg, uint32 len_arg,
 	     unireg_check_arg, field_name_arg, table_arg, cs)
 {
   flags|=ZEROFILL_FLAG; /* 4.0 MYD compatibility */
-  if (table && !table->timestamp_field)
+  if (table && !table->timestamp_field && 
+      unireg_check != NONE)
   {
-    table->timestamp_field= this;		// Automatic timestamp
+    /* This timestamp has auto-update */
-    table->time_stamp=(ulong) (ptr_arg - (char*) table->record[0])+1;
+    table->timestamp_field= this;
     flags|=TIMESTAMP_FLAG;
   }
 }
 
 
+/*
+    Sets TABLE::timestamp_default_now and TABLE::timestamp_on_update_now 
+    members according to unireg type of this TIMESTAMP field.
+  
+  SYNOPSIS
+    Field_timestamp::set_timestamp_offsets()
+  
+*/
+void Field_timestamp::set_timestamp_offsets()
+{
+  ulong timestamp= (ulong) (ptr - (char*) table->record[0]) + 1;
+  
+  DBUG_ASSERT(table->timestamp_field == this && unireg_check != NONE);
+
+  table->timestamp_default_now= 
+    (unireg_check == TIMESTAMP_UN_FIELD)? 0 : timestamp;
+  table->timestamp_on_update_now= 
+    (unireg_check == TIMESTAMP_DN_FIELD)? 0 : timestamp;
+}
+
+
 int Field_timestamp::store(const char *from,uint len,CHARSET_INFO *cs)
 {
   long tmp=(long) str_to_timestamp(from,len);

sql/field.h

@@ -52,9 +52,18 @@ public:
   ulong		query_id;		// For quick test of used fields
   /* Field is part of the following keys */
   key_map	key_start,part_of_key,part_of_sortkey;
+  /* 
+    We use three additional unireg types for TIMESTAMP to overcome limitation 
+    of current binary format of .frm file. We'd like to be able to support 
+    NOW() as default and on update value for such fields but unable to hold 
+    this info anywhere except unireg_check field. This issue will be resolved
+    in more clean way with transition to new text based .frm format.
+    See also comment for Field_timestamp::Field_timestamp().
+  */
   enum utype  { NONE,DATE,SHIELD,NOEMPTY,CASEUP,PNR,BGNR,PGNR,YES,NO,REL,
 		CHECK,EMPTY,UNKNOWN_FIELD,CASEDN,NEXT_NUMBER,INTERVAL_FIELD,
-		BIT_FIELD, TIMESTAMP_FIELD,CAPITALIZE,BLOB_FIELD};
+                BIT_FIELD, TIMESTAMP_OLD_FIELD, CAPITALIZE, BLOB_FIELD,
+                TIMESTAMP_DN_FIELD, TIMESTAMP_UN_FIELD, TIMESTAMP_DNUN_FIELD};
   enum geometry_type
   {
     GEOM_GEOMETRY = 0, GEOM_POINT = 1, GEOM_LINESTRING = 2, GEOM_POLYGON = 3,
@@ -644,7 +653,8 @@ public:
   void set_time();
   virtual void set_default()
   {
-    if (table->timestamp_field == this)
+    if (table->timestamp_field == this &&
+        unireg_check != TIMESTAMP_UN_FIELD)
       set_time();
     else
       Field::set_default();
@@ -662,6 +672,7 @@ public:
   bool get_date(TIME *ltime,uint fuzzydate);
   bool get_time(TIME *ltime);
   field_cast_enum field_cast_type() { return FIELD_CAST_TIMESTAMP; }
+  void set_timestamp_offsets();
 };
 
 

sql/ha_berkeley.cc

@@ -826,8 +826,8 @@ int ha_berkeley::write_row(byte * record)
   DBUG_ENTER("write_row");
 
   statistic_increment(ha_write_count,&LOCK_status);
-  if (table->time_stamp)
+  if (table->timestamp_default_now)
-    update_timestamp(record+table->time_stamp-1);
+    update_timestamp(record+table->timestamp_default_now-1);
   if (table->next_number_field && record == table->record[0])
     update_auto_increment();
   if ((error=pack_row(&row, record,1)))
@@ -1073,8 +1073,8 @@ int ha_berkeley::update_row(const byte * old_row, byte * new_row)
   LINT_INIT(error);
 
   statistic_increment(ha_update_count,&LOCK_status);
-  if (table->time_stamp)
+  if (table->timestamp_on_update_now)
-    update_timestamp(new_row+table->time_stamp-1);
+    update_timestamp(new_row+table->timestamp_on_update_now-1);
 
   if (hidden_primary_key)
   {

sql/ha_heap.cc

@@ -65,8 +65,8 @@ int ha_heap::close(void)
 int ha_heap::write_row(byte * buf)
 {
   statistic_increment(ha_write_count,&LOCK_status);
-  if (table->time_stamp)
+  if (table->timestamp_default_now)
-    update_timestamp(buf+table->time_stamp-1);
+    update_timestamp(buf+table->timestamp_default_now-1);
   if (table->next_number_field && buf == table->record[0])
     update_auto_increment();
   return heap_write(file,buf);
@@ -75,8 +75,8 @@ int ha_heap::write_row(byte * buf)
 int ha_heap::update_row(const byte * old_data, byte * new_data)
 {
   statistic_increment(ha_update_count,&LOCK_status);
-  if (table->time_stamp)
+  if (table->timestamp_on_update_now)
-    update_timestamp(new_data+table->time_stamp-1);
+    update_timestamp(new_data+table->timestamp_on_update_now-1);
   return heap_update(file,old_data,new_data);
 }
 

sql/ha_innodb.cc

@@ -2137,9 +2137,8 @@ ha_innobase::write_row(
 
   	statistic_increment(ha_write_count, &LOCK_status);
 
-  	if (table->time_stamp) {
+        if (table->timestamp_default_now)
-    		update_timestamp(record + table->time_stamp - 1);
+                update_timestamp(record + table->timestamp_default_now - 1);
-    	}
 
 	if (last_query_id != user_thd->query_id) {
 	        prebuilt->sql_stat_start = TRUE;
@@ -2510,9 +2509,8 @@ ha_innobase::update_row(
 	ut_ad(prebuilt->trx ==
 		(trx_t*) current_thd->transaction.all.innobase_tid);
 
-        if (table->time_stamp) {
+        if (table->timestamp_on_update_now)
-                update_timestamp(new_row + table->time_stamp - 1);
+                update_timestamp(new_row + table->timestamp_on_update_now - 1);
-	}
 
 	if (last_query_id != user_thd->query_id) {
 	        prebuilt->sql_stat_start = TRUE;

sql/ha_isam.cc

@@ -70,8 +70,8 @@ uint ha_isam::min_record_length(uint options) const
 int ha_isam::write_row(byte * buf)
 {
   statistic_increment(ha_write_count,&LOCK_status);
-  if (table->time_stamp)
+  if (table->timestamp_default_now)
-    update_timestamp(buf+table->time_stamp-1);
+    update_timestamp(buf+table->timestamp_default_now-1);
   if (table->next_number_field && buf == table->record[0])
     update_auto_increment();
   return !nisam_write(file,buf) ? 0 : my_errno ? my_errno : -1;
@@ -80,8 +80,8 @@ int ha_isam::write_row(byte * buf)
 int ha_isam::update_row(const byte * old_data, byte * new_data)
 {
   statistic_increment(ha_update_count,&LOCK_status);
-  if (table->time_stamp)
+  if (table->timestamp_on_update_now)
-    update_timestamp(new_data+table->time_stamp-1);
+    update_timestamp(new_data+table->timestamp_on_update_now-1);
   return !nisam_update(file,old_data,new_data) ? 0 : my_errno ? my_errno : -1;
 }
 

sql/ha_isammrg.cc

@@ -78,8 +78,8 @@ int ha_isammrg::write_row(byte * buf)
 int ha_isammrg::update_row(const byte * old_data, byte * new_data)
 {
   statistic_increment(ha_update_count,&LOCK_status);
-  if (table->time_stamp)
+  if (table->timestamp_on_update_now)
-    update_timestamp(new_data+table->time_stamp-1);
+    update_timestamp(new_data+table->timestamp_on_update_now-1);
   return !mrg_update(file,old_data,new_data) ? 0 : my_errno ? my_errno : -1;
 }
 

sql/ha_myisam.cc

@@ -253,9 +253,8 @@ int ha_myisam::write_row(byte * buf)
   statistic_increment(ha_write_count,&LOCK_status);
 
   /* If we have a timestamp column, update it to the current time */
-
+  if (table->timestamp_default_now)
-  if (table->time_stamp)
+    update_timestamp(buf+table->timestamp_default_now-1);
-    update_timestamp(buf+table->time_stamp-1);
 
   /*
     If we have an auto_increment column and we are writing a changed row
@@ -937,8 +936,8 @@ bool ha_myisam::is_crashed() const
 int ha_myisam::update_row(const byte * old_data, byte * new_data)
 {
   statistic_increment(ha_update_count,&LOCK_status);
-  if (table->time_stamp)
+  if (table->timestamp_on_update_now)
-    update_timestamp(new_data+table->time_stamp-1);
+    update_timestamp(new_data+table->timestamp_on_update_now-1);
   return mi_update(file,old_data,new_data);
 }
 

sql/ha_myisammrg.cc

@@ -82,8 +82,8 @@ int ha_myisammrg::close(void)
 int ha_myisammrg::write_row(byte * buf)
 {
   statistic_increment(ha_write_count,&LOCK_status);
-  if (table->time_stamp)
+  if (table->timestamp_default_now)
-    update_timestamp(buf+table->time_stamp-1);
+    update_timestamp(buf+table->timestamp_default_now-1);
   if (table->next_number_field && buf == table->record[0])
       update_auto_increment();
   return myrg_write(file,buf);
@@ -92,8 +92,8 @@ int ha_myisammrg::write_row(byte * buf)
 int ha_myisammrg::update_row(const byte * old_data, byte * new_data)
 {
   statistic_increment(ha_update_count,&LOCK_status);
-  if (table->time_stamp)
+  if (table->timestamp_on_update_now)
-    update_timestamp(new_data+table->time_stamp-1);
+    update_timestamp(new_data+table->timestamp_on_update_now);
   return myrg_update(file,old_data,new_data);
 }
 

sql/item_func.h

@@ -47,7 +47,7 @@ public:
 		  SP_CONTAINS_FUNC,SP_OVERLAPS_FUNC,
 		  SP_STARTPOINT,SP_ENDPOINT,SP_EXTERIORRING,
 		  SP_POINTN,SP_GEOMETRYN,SP_INTERIORRINGN,
-		  NOT_FUNC, NOT_ALL_FUNC};
+		  NOT_FUNC, NOT_ALL_FUNC, NOW_FUNC};
   enum optimize_type { OPTIMIZE_NONE,OPTIMIZE_KEY,OPTIMIZE_OP, OPTIMIZE_NULL };
   enum Type type() const { return FUNC_ITEM; }
   virtual enum Functype functype() const   { return UNKNOWN_FUNC; }

sql/item_timefunc.h

@@ -469,6 +469,7 @@ public:
   Item_func_now_local(Item *a) :Item_func_now(a) {}
   const char *func_name() const { return "now"; }
   void store_now_in_tm(time_t now, struct tm *now_tm);
+  virtual enum Functype functype() const { return NOW_FUNC; }
 };
 
 

sql/mysql_priv.h

@@ -633,7 +633,7 @@ void set_item_name(Item *item,char *pos,uint length);
 bool add_field_to_list(THD *thd, char *field_name, enum enum_field_types type,
 		       char *length, char *decimal,
 		       uint type_modifier,
-		       Item *default_value,
+		       Item *default_value, Item *on_update_value,
 		       LEX_STRING *comment,
 		       char *change, TYPELIB *interval,CHARSET_INFO *cs,
 		       uint uint_geom_type);

sql/share/czech/errmsg.txt

@@ -305,3 +305,5 @@ character-set=latin2
 "The MySQL server is running with the %s option so it cannot execute this statement",
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/danish/errmsg.txt

@@ -299,3 +299,5 @@ character-set=latin1
 "The MySQL server is running with the %s option so it cannot execute this statement",
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/dutch/errmsg.txt

@@ -307,3 +307,5 @@ character-set=latin1
 "The MySQL server is running with the %s option so it cannot execute this statement",
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/english/errmsg.txt

@@ -296,3 +296,5 @@ character-set=latin1
 "The MySQL server is running with the %s option so it cannot execute this statement",
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/estonian/errmsg.txt

@@ -301,3 +301,5 @@ character-set=latin7
 "The MySQL server is running with the %s option so it cannot execute this statement",
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/french/errmsg.txt

@@ -296,3 +296,5 @@ character-set=latin1
 "The MySQL server is running with the %s option so it cannot execute this statement",
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/german/errmsg.txt

@@ -308,3 +308,5 @@ character-set=latin1
 "The MySQL server is running with the %s option so it cannot execute this statement",
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/greek/errmsg.txt

@@ -296,3 +296,5 @@ character-set=greek
 "The MySQL server is running with the %s option so it cannot execute this statement",
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/hungarian/errmsg.txt

@@ -298,3 +298,5 @@ character-set=latin2
 "The MySQL server is running with the %s option so it cannot execute this statement",
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/italian/errmsg.txt

@@ -296,3 +296,5 @@ character-set=latin1
 "The MySQL server is running with the %s option so it cannot execute this statement",
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/japanese/errmsg.txt

@@ -298,3 +298,5 @@ character-set=ujis
 "The MySQL server is running with the %s option so it cannot execute this statement",
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/korean/errmsg.txt

@@ -296,3 +296,5 @@ character-set=euckr
 "The MySQL server is running with the %s option so it cannot execute this statement",
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/norwegian-ny/errmsg.txt

@@ -298,3 +298,5 @@ character-set=latin1
 "The MySQL server is running with the %s option so it cannot execute this statement",
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/norwegian/errmsg.txt

@@ -298,3 +298,5 @@ character-set=latin1
 "The MySQL server is running with the %s option so it cannot execute this statement",
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/polish/errmsg.txt

@@ -300,3 +300,5 @@ character-set=latin2
 "The MySQL server is running with the %s option so it cannot execute this statement",
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/portuguese/errmsg.txt

@@ -297,3 +297,5 @@ character-set=latin1
 "The MySQL server is running with the %s option so it cannot execute this statement",
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/romanian/errmsg.txt

@@ -300,3 +300,5 @@ character-set=latin2
 "The MySQL server is running with the %s option so it cannot execute this statement",
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/russian/errmsg.txt

@@ -298,3 +298,5 @@ character-set=koi8r
 "The MySQL server is running with the %s option so it cannot execute this statement",
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/serbian/errmsg.txt

@@ -290,3 +290,5 @@ character-set=cp1250
 "The MySQL server is running with the %s option so it cannot execute this statement"
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/slovak/errmsg.txt

@@ -304,3 +304,5 @@ character-set=latin2
 "The MySQL server is running with the %s option so it cannot execute this statement",
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/spanish/errmsg.txt

@@ -298,3 +298,5 @@ character-set=latin1
 "The MySQL server is running with the %s option so it cannot execute this statement",
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/swedish/errmsg.txt

@@ -293,6 +293,7 @@ character-set=latin1
 "Tabel %-.100s anv<6E>nd med '%s' <20>r inte uppdateringsbar",
 "'%s' <20>r inte aktiverad; F<>r att aktivera detta m<>ste du bygga om MySQL med '%s' definerad",
 "MySQL <20>r started i --skip-grant-tables mod. Pga av detta kan du inte anv<6E>nda detta program",
-
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/share/ukrainian/errmsg.txt

@@ -301,3 +301,5 @@ character-set=koi8u
 "The MySQL server is running with the %s option so it cannot execute this statement",
 "Column '%-.100s' has duplicated value '%-.64s' in %s"
 "Truncated wrong %-.32s value: '%-.128s'"
+"Incorrect table definition; There can only be one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause"
+"Invalid ON UPDATE clause for '%-.64s' field",

sql/sql_base.cc

@@ -939,6 +939,8 @@ TABLE *open_table(THD *thd,const char *db,const char *table_name,
   table->status=STATUS_NO_RECORD;
   table->keys_in_use_for_query= table->keys_in_use;
   table->used_keys= table->keys_for_keyread;
+  if (table->timestamp_field)
+    table->timestamp_field->set_timestamp_offsets();
   DBUG_ASSERT(table->key_read == 0);
   DBUG_RETURN(table);
 }

sql/sql_insert.cc

@@ -42,9 +42,9 @@ static void unlink_blobs(register TABLE *table);
 #define DELAYED_LOG_BIN    2
 
 /*
-  Check if insert fields are correct
+  Check if insert fields are correct.
-  Updates table->time_stamp to point to timestamp field or 0, depending on
+  Sets table->timestamp_default_now/on_update_now to 0 o leaves it to point
-  if timestamp should be updated or not.
+  to timestamp field, depending on if timestamp should be updated or not.
 */
 
 int
@@ -65,7 +65,7 @@ check_insert_fields(THD *thd,TABLE *table,List<Item> &fields,
 	check_grant_all_columns(thd,INSERT_ACL,table))
       return -1;
 #endif
-    table->time_stamp=0;			// This is saved by caller
+    table->timestamp_default_now= table->timestamp_on_update_now= 0;
   }
   else
   {						// Part field list
@@ -97,10 +97,9 @@ check_insert_fields(THD *thd,TABLE *table,List<Item> &fields,
       my_error(ER_FIELD_SPECIFIED_TWICE,MYF(0), thd->dupp_field->field_name);
       return -1;
     }
-    table->time_stamp=0;
     if (table->timestamp_field &&	// Don't set timestamp if used
-	table->timestamp_field->query_id != thd->query_id)
+	table->timestamp_field->query_id == thd->query_id)
-      table->time_stamp= table->timestamp_field->offset()+1;
+      table->timestamp_default_now= table->timestamp_on_update_now= 0;
   }
   // For the values we need select_priv
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
@@ -551,9 +550,12 @@ int write_record(TABLE *table,COPY_INFO *info)
 	  an INSERT or DELETE(s) + INSERT; FOREIGN KEY checks in
 	  InnoDB do not function in the defined way if we allow MySQL
 	  to convert the latter operation internally to an UPDATE.
+          We also should not perform this conversion if we have 
+          timestamp field with ON UPDATE which is different from DEFAULT.
 	*/
 	if (last_uniq_key(table,key_nr) &&
-	    !table->file->referenced_by_foreign_key())
+	    !table->file->referenced_by_foreign_key() &&
+            table->timestamp_default_now == table->timestamp_on_update_now)
         {
           if ((error=table->file->update_row(table->record[1],
 					     table->record[0])))
@@ -629,7 +631,8 @@ public:
   bool query_start_used,last_insert_id_used,insert_id_used;
   int log_query;
   ulonglong last_insert_id;
-  ulong time_stamp;
+  ulong timestamp_default_now;
+  ulong timestamp_on_update_now;
   uint query_length;
 
   delayed_row(enum_duplicates dup_arg, int log_query_arg)
@@ -920,9 +923,10 @@ TABLE *delayed_insert::get_local_table(THD* client_thd)
   if (table->timestamp_field)
   {
     /* Restore offset as this may have been reset in handle_inserts */
-    copy->time_stamp=table->timestamp_field->offset()+1;
     copy->timestamp_field=
       (Field_timestamp*) copy->field[table->timestamp_field_offset];
+    copy->timestamp_field->unireg_check= table->timestamp_field->unireg_check;
+    copy->timestamp_field->set_timestamp_offsets();
   }
 
   /* _rowid is not used with delayed insert */
@@ -973,7 +977,8 @@ static int write_delayed(THD *thd,TABLE *table,enum_duplicates duplic,
   row->last_insert_id_used=	thd->last_insert_id_used;
   row->insert_id_used=		thd->insert_id_used;
   row->last_insert_id=		thd->last_insert_id;
-  row->time_stamp=		table->time_stamp;
+  row->timestamp_default_now=	table->timestamp_default_now;
+  row->timestamp_on_update_now=	table->timestamp_on_update_now;
 
   di->rows.push_back(row);
   di->stacked_inserts++;
@@ -1307,7 +1312,8 @@ bool delayed_insert::handle_inserts(void)
     thd.last_insert_id=row->last_insert_id;
     thd.last_insert_id_used=row->last_insert_id_used;
     thd.insert_id_used=row->insert_id_used;
-    table->time_stamp=row->time_stamp;
+    table->timestamp_default_now= row->timestamp_default_now;
+    table->timestamp_on_update_now= row->timestamp_on_update_now;
 
     info.handle_duplicates= row->dup;
     if (info.handle_duplicates == DUP_IGNORE ||
@@ -1597,11 +1603,9 @@ select_create::prepare(List<Item> &values, SELECT_LEX_UNIT *u)
   /* First field to copy */
   field=table->field+table->fields - values.elements;
 
-  if (table->timestamp_field)			// Don't set timestamp if used
+  /* Don't set timestamp if used */
-  {
+  table->timestamp_default_now= table->timestamp_on_update_now= 0;
-    table->timestamp_field->set_time();
+  
-    table->time_stamp=0;			// This should be saved
-  }
   table->next_number_field=table->found_next_number_field;
 
   restore_record(table,default_values);			// Get empty record

sql/sql_lex.h

@@ -532,7 +532,7 @@ typedef struct st_lex
   String *wild;
   sql_exchange *exchange;
   select_result *result;
-  Item *default_value;
+  Item *default_value, *on_update_value;
   LEX_STRING *comment, name_and_length;
   LEX_USER *grant_user;
   gptr yacc_yyss,yacc_yyvs;

sql/sql_load.cc

@@ -274,9 +274,9 @@ int mysql_load(THD *thd,sql_exchange *ex,TABLE_LIST *table_list,
 
   if (!(error=test(read_info.error)))
   {
-    uint save_time_stamp=table->time_stamp;
     if (use_timestamp)
-      table->time_stamp=0;
+      table->timestamp_default_now= table->timestamp_on_update_now= 0;
+    
     table->next_number_field=table->found_next_number_field;
     VOID(table->file->extra_opt(HA_EXTRA_WRITE_CACHE,
 			    thd->variables.read_buff_size));
@@ -297,7 +297,6 @@ int mysql_load(THD *thd,sql_exchange *ex,TABLE_LIST *table_list,
     if (table->file->activate_all_index(thd))
       error=1;					/* purecov: inspected */
     table->file->extra(HA_EXTRA_NO_IGNORE_DUP_KEY);
-    table->time_stamp=save_time_stamp;
     table->next_number_field=0;
   }
   if (file >= 0)

sql/sql_parse.cc

@@ -4001,7 +4001,8 @@ bool mysql_test_parse_for_slave(THD *thd, char *inBuf, uint length)
 bool add_field_to_list(THD *thd, char *field_name, enum_field_types type,
 		       char *length, char *decimals,
 		       uint type_modifier,
-		       Item *default_value, LEX_STRING *comment,
+		       Item *default_value, Item *on_update_value,
+                       LEX_STRING *comment,
 		       char *change, TYPELIB *interval, CHARSET_INFO *cs,
 		       uint uint_geom_type)
 {
@@ -4037,11 +4038,17 @@ bool add_field_to_list(THD *thd, char *field_name, enum_field_types type,
       Default value should be literal => basic constants =>
       no need fix_fields()
       
-      We allow specifying value for first TIMESTAMP column 
+      We allow only one function as part of default value - 
-      altough it is silently ignored. This should be fixed in 4.1
+      NOW() as default for TIMESTAMP type.
-      (by proper warning or real support for default values)
     */
-    if (default_value->type() == Item::NULL_ITEM)
+    if (default_value->type() == Item::FUNC_ITEM && 
+        !(((Item_func*)default_value)->functype() == Item_func::NOW_FUNC &&
+         type == FIELD_TYPE_TIMESTAMP))
+    {
+      net_printf(thd, ER_INVALID_DEFAULT, field_name);
+      DBUG_RETURN(1);
+    }
+    else if (default_value->type() == Item::NULL_ITEM)
     {
       default_value=0;
       if ((type_modifier & (NOT_NULL_FLAG | AUTO_INCREMENT_FLAG)) ==
@@ -4057,6 +4064,13 @@ bool add_field_to_list(THD *thd, char *field_name, enum_field_types type,
       DBUG_RETURN(1);
     }
   }
+
+  if (on_update_value && type != FIELD_TYPE_TIMESTAMP)
+  {
+    net_printf(thd, ER_INVALID_ON_UPDATE, field_name);
+    DBUG_RETURN(1);
+  }
+    
   if (!(new_field=new create_field()))
     DBUG_RETURN(1);
   new_field->field=0;
@@ -4220,6 +4234,34 @@ bool add_field_to_list(THD *thd, char *field_name, enum_field_types type,
       new_field->length= min(new_field->length,14); /* purecov: inspected */
     }
     new_field->flags|= ZEROFILL_FLAG | UNSIGNED_FLAG | NOT_NULL_FLAG;
+    if (default_value)
+    {
+      /* Grammar allows only NOW() value for ON UPDATE clause */
+      if (default_value->type() == Item::FUNC_ITEM && 
+          ((Item_func*)default_value)->functype() == Item_func::NOW_FUNC)
+      {
+        new_field->unireg_check= (on_update_value?Field::TIMESTAMP_DNUN_FIELD:
+                                                  Field::TIMESTAMP_DN_FIELD);
+        /*
+          We don't need default value any longer moreover it is dangerous.
+          Everything handled by unireg_check further.
+        */
+        new_field->def= 0;
+      }
+      else
+        new_field->unireg_check= (on_update_value?Field::TIMESTAMP_UN_FIELD:
+                                                  Field::NONE);
+    }
+    else
+    {
+      /* 
+        We are setting TIMESTAMP_OLD_FIELD here only temporary, we will 
+        replace this value by TIMESTAMP_DNUN_FIELD or NONE later when 
+        information about all TIMESTAMP fields in table will be availiable.
+      */
+      new_field->unireg_check= on_update_value?Field::TIMESTAMP_UN_FIELD:
+                                               Field::TIMESTAMP_OLD_FIELD;
+    }
     break;
   case FIELD_TYPE_DATE:				// Old date type
     if (protocol_version != PROTOCOL_VERSION-1)

sql/sql_show.cc

@@ -699,7 +699,6 @@ mysqld_show_fields(THD *thd, TABLE_LIST *table_list,const char *wild,
         uint flags=field->flags;
         String type(tmp,sizeof(tmp), system_charset_info);
         uint col_access;
-        bool null_default_value=0;
 
 	protocol->prepare_for_resend();
         protocol->store(field->field_name, system_charset_info);
@@ -723,20 +722,24 @@ mysqld_show_fields(THD *thd, TABLE_LIST *table_list,const char *wild,
                      (field->flags & MULTIPLE_KEY_FLAG) ? "MUL":"");
         protocol->store((char*) pos, system_charset_info);
 
-        /*
+        if (table->timestamp_field == field &&
-          We handle first TIMESTAMP column in special way because its
+            field->unireg_check != Field::TIMESTAMP_UN_FIELD)
-          default value is ignored and current timestamp used instead.
+        {
-        */
+          /*
-        if (table->timestamp_field == field ||
+            We have NOW() as default value but we use CURRENT_TIMESTAMP form
-            field->unireg_check == Field::NEXT_NUMBER)
+            because it is more SQL standard comatible
-          null_default_value=1;
+          */
-        if (!null_default_value && !field->is_null())
+          protocol->store("CURRENT_TIMESTAMP", system_charset_info);
+        }
+        else if (field->unireg_check != Field::NEXT_NUMBER && 
+                 !field->is_null())
         {                                               // Not null by default
           type.set(tmp, sizeof(tmp), field->charset());
           field->val_str(&type,&type);
           protocol->store(type.ptr(),type.length(),type.charset());
         }
-        else if (field->maybe_null() || null_default_value)
+        else if (field->unireg_check == Field::NEXT_NUMBER ||
+                 field->maybe_null())
           protocol->store_null();                       // Null as default
         else
           protocol->store("",0, system_charset_info);	// empty string
@@ -1232,6 +1235,7 @@ store_create_info(THD *thd, TABLE *table, String *packet)
   for (ptr=table->field ; (field= *ptr); ptr++)
   {
     bool has_default;
+    bool has_now_default;
     uint flags = field->flags;
 
     if (ptr != table->field)
@@ -1268,14 +1272,25 @@ store_create_info(THD *thd, TABLE *table, String *packet)
     if (flags & NOT_NULL_FLAG)
       packet->append(" NOT NULL", 9);
 
+
+    /* 
+      Again we are using CURRENT_TIMESTAMP instead of NOW becaus eit is
+      more standard 
+    */
+    has_now_default= table->timestamp_field == field && 
+                     field->unireg_check != Field::TIMESTAMP_UN_FIELD;
+    
     has_default= (field->type() != FIELD_TYPE_BLOB &&
-		  table->timestamp_field != field &&
+		  field->unireg_check != Field::NEXT_NUMBER &&
-		  field->unireg_check != Field::NEXT_NUMBER);
+                  !((foreign_db_mode || limited_mysql_mode) &&
+                    has_now_default));
 
     if (has_default)
     {
       packet->append(" default ", 9);
-      if (!field->is_null())
+      if (has_now_default)
+        packet->append("CURRENT_TIMESTAMP",17);
+      else if (!field->is_null())
       {                                             // Not null by default
         type.set(tmp, sizeof(tmp), field->charset());
         field->val_str(&type,&type);
@@ -1296,6 +1311,11 @@ store_create_info(THD *thd, TABLE *table, String *packet)
         packet->append(tmp,0);
     }
 
+    if (!foreign_db_mode && !limited_mysql_mode &&
+        table->timestamp_field == field && 
+        field->unireg_check != Field::TIMESTAMP_DN_FIELD)
+      packet->append(" on update CURRENT_TIMESTAMP",28);
+
     if (field->unireg_check == Field::NEXT_NUMBER && !foreign_db_mode)
       packet->append(" auto_increment", 15 );
 

sql/sql_table.cc

@@ -427,6 +427,7 @@ int mysql_create_table(THD *thd,const char *db, const char *table_name,
   KEY	        *key_info,*key_info_buffer;
   KEY_PART_INFO *key_part_info;
   int		auto_increment=0;
+  int           timestamps= 0, timestamps_with_niladic= 0;
   handler	*file;
   int           field_no,dup_no;
   enum db_type	new_db_type;
@@ -621,8 +622,22 @@ int mysql_create_table(THD *thd,const char *db, const char *table_name,
       sql_field->pack_flag=f_settype((uint) sql_field->sql_type);
       break;
     case FIELD_TYPE_TIMESTAMP:
-      sql_field->unireg_check=Field::TIMESTAMP_FIELD;
+      /* We should replace old TIMESTAMP fields with their newer analogs */
-      /* fall through */
+      if (sql_field->unireg_check == Field::TIMESTAMP_OLD_FIELD)
+      {
+        if (!timestamps)
+        {
+          sql_field->unireg_check= Field::TIMESTAMP_DNUN_FIELD;
+          ++timestamps_with_niladic;
+        }
+        else
+          sql_field->unireg_check= Field::NONE;
+      }
+      else if(sql_field->unireg_check != Field::NONE)
+        ++timestamps_with_niladic;
+      
+      ++timestamps;
+      /* fall-through */
     default:
       sql_field->pack_flag=(FIELDFLAG_NUMBER |
 			    (sql_field->flags & UNSIGNED_FLAG ? 0 :
@@ -640,6 +655,11 @@ int mysql_create_table(THD *thd,const char *db, const char *table_name,
       auto_increment++;
     pos+=sql_field->pack_length;
   }
+  if (timestamps_with_niladic > 1)
+  {
+    my_error(ER_TOO_MUCH_AUTO_TIMESTAMP_COLS,MYF(0));
+    DBUG_RETURN(-1);
+  }
   if (auto_increment > 1)
   {
     my_error(ER_WRONG_AUTO_KEY,MYF(0));
@@ -2100,10 +2120,9 @@ int mysql_alter_table(THD *thd,char *new_db, char *new_name,
   char tmp_name[80],old_name[32],new_name_buff[FN_REFLEN];
   char new_alias_buff[FN_REFLEN], *table_name, *db, *new_alias, *alias;
   char index_file[FN_REFLEN], data_file[FN_REFLEN];
-  bool use_timestamp=0;
   ha_rows copied,deleted;
   ulonglong next_insert_id;
-  uint save_time_stamp,db_create_options, used_fields;
+  uint db_create_options, used_fields;
   enum db_type old_db_type,new_db_type;
   DBUG_ENTER("mysql_alter_table");
 
@@ -2321,8 +2340,6 @@ int mysql_alter_table(THD *thd,char *new_db, char *new_name,
     if (def)
     {						// Field is changed
       def->field=field;
-      if (def->sql_type == FIELD_TYPE_TIMESTAMP)
-	use_timestamp=1;
       if (!def->after)
       {
 	create_list.push_back(def);
@@ -2332,9 +2349,6 @@ int mysql_alter_table(THD *thd,char *new_db, char *new_name,
     else
     {						// Use old field value
       create_list.push_back(def=new create_field(field,field));
-      if (def->sql_type == FIELD_TYPE_TIMESTAMP)
-	use_timestamp=1;
-
       alter_it.rewind();			// Change default if ALTER
       Alter_column *alter;
       while ((alter=alter_it++))
@@ -2587,9 +2601,13 @@ int mysql_alter_table(THD *thd,char *new_db, char *new_name,
     goto err;
   }
 
-  save_time_stamp=new_table->time_stamp;
+ 
-  if (use_timestamp)
+  /* 
-    new_table->time_stamp=0;
+    We don't want update TIMESTAMP fields during ALTER TABLE 
+    and copy_data_between_tables uses only write_row() for new_table so
+    don't need to set up timestamp_on_update_now member.
+  */
+  new_table->timestamp_default_now= 0;
   new_table->next_number_field=new_table->found_next_number_field;
   thd->count_cuted_fields= CHECK_FIELD_WARN;	// calc cuted fields
   thd->cuted_fields=0L;
@@ -2602,7 +2620,6 @@ int mysql_alter_table(THD *thd,char *new_db, char *new_name,
 				   order_num, order, &copied, &deleted);
   thd->last_insert_id=next_insert_id;		// Needed for correct log
   thd->count_cuted_fields= CHECK_FIELD_IGNORE;
-  new_table->time_stamp=save_time_stamp;
 
   if (table->tmp_table)
   {

sql/sql_update.cc

@@ -120,7 +120,6 @@ int mysql_update(THD *thd,
   {
     timestamp_query_id=table->timestamp_field->query_id;
     table->timestamp_field->query_id=thd->query_id-1;
-    table->time_stamp= table->timestamp_field->offset() +1;
   }
 
   /* Check the fields we are going to modify */
@@ -133,7 +132,7 @@ int mysql_update(THD *thd,
   {
     // Don't set timestamp column if this is modified
     if (table->timestamp_field->query_id == thd->query_id)
-      table->time_stamp=0;
+      table->timestamp_on_update_now= 0;
     else
       table->timestamp_field->query_id=timestamp_query_id;
   }
@@ -486,13 +485,11 @@ int mysql_multi_update(THD *thd,
 
     /* We only need SELECT privilege for columns in the values list */
     table->grant.want_privilege= (SELECT_ACL & ~table->grant.privilege);
-    if (table->timestamp_field)
+    // Only set timestamp column if this is not modified
-    {
+    if (table->timestamp_field &&
-      table->time_stamp=0;
+        table->timestamp_field->query_id == thd->query_id)
-      // Only set timestamp column if this is not modified
+      table->timestamp_on_update_now= 0;
-      if (table->timestamp_field->query_id != thd->query_id)
+    
-	table->time_stamp= table->timestamp_field->offset() +1;
-    }
     if (tl->derived)
       derived_tables|= table->map;
   }

sql/sql_yacc.yy

@@ -629,7 +629,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b,int *yystacksize);
 	using_list expr_or_default set_expr_or_default interval_expr
 	param_marker singlerow_subselect singlerow_subselect_init
 	exists_subselect exists_subselect_init geometry_function
-	signed_literal
+	signed_literal now_or_signed_literal
 
 %type <item_num>
 	NUM_literal
@@ -1226,7 +1226,7 @@ field_spec:
 	 {
 	   LEX *lex=Lex;
 	   lex->length=lex->dec=0; lex->type=0; lex->interval=0;
-	   lex->default_value=0;
+	   lex->default_value= lex->on_update_value= 0;
 	   lex->comment=0;
 	   lex->charset=NULL;
 	 }
@@ -1236,7 +1236,8 @@ field_spec:
 	  if (add_field_to_list(lex->thd, $1.str,
 				(enum enum_field_types) $3,
 				lex->length,lex->dec,lex->type,
-				lex->default_value, lex->comment,
+				lex->default_value, lex->on_update_value, 
+                                lex->comment,
 				lex->change,lex->interval,lex->charset,
 				lex->uint_geom_type))
 	    YYABORT;
@@ -1432,7 +1433,9 @@ opt_attribute_list:
 attribute:
 	NULL_SYM	  { Lex->type&= ~ NOT_NULL_FLAG; }
 	| NOT NULL_SYM	  { Lex->type|= NOT_NULL_FLAG; }
-	| DEFAULT signed_literal { Lex->default_value=$2; }
+	| DEFAULT now_or_signed_literal { Lex->default_value=$2; }
+	| ON UPDATE_SYM NOW_SYM optional_braces 
+          { Lex->on_update_value= new Item_func_now_local(); }
 	| AUTO_INC	  { Lex->type|= AUTO_INCREMENT_FLAG | NOT_NULL_FLAG; }
 	| SERIAL_SYM DEFAULT VALUE_SYM
 	  { Lex->type|= AUTO_INCREMENT_FLAG | NOT_NULL_FLAG | UNIQUE_FLAG; }
@@ -1456,6 +1459,11 @@ attribute:
 	  }
 	;
 
+now_or_signed_literal:
+        NOW_SYM optional_braces { $$= new Item_func_now_local(); }
+        | signed_literal { $$=$1; }
+        ;
+
 charset:
 	CHAR_SYM SET	{}
 	| CHARSET	{}
@@ -1725,7 +1733,7 @@ alter_list_item:
           {
             LEX *lex=Lex;
             lex->length=lex->dec=0; lex->type=0; lex->interval=0;
-            lex->default_value=0;
+            lex->default_value= lex->on_update_value= 0;
 	    lex->comment=0;
 	    lex->charset= NULL;
             lex->simple_alter=0;
@@ -1736,7 +1744,8 @@ alter_list_item:
             if (add_field_to_list(lex->thd,$3.str,
                                   (enum enum_field_types) $5,
                                   lex->length,lex->dec,lex->type,
-                                  lex->default_value, lex->comment,
+                                  lex->default_value, lex->on_update_value,
+                                  lex->comment,
 				  $3.str, lex->interval, lex->charset,
 				  lex->uint_geom_type))
 	       YYABORT;

sql/table.h

@@ -97,8 +97,20 @@ struct st_table {
   uint raid_type,raid_chunks;
   uint status;				/* Used by postfix.. */
   uint system;				/* Set if system record */
-  ulong time_stamp;			/* Set to offset+1 of record */
+
+  /* 
+    These two members hold offset in record + 1 for TIMESTAMP field
+    with NOW() as default value or/and with ON UPDATE NOW() option. 
+    If 0 then such field is absent in this table or auto-set for default
+    or/and on update should be temporaly disabled for some reason.
+    These values is setup to offset value for each statement in open_table()
+    and turned off in statement processing code (see mysql_update as example).
+  */
+  ulong timestamp_default_now;
+  ulong timestamp_on_update_now;
+  /* Index of auto-updated TIMESTAMP field in field array */
   uint timestamp_field_offset;
+  
   uint next_number_index;
   uint blob_ptr_size;			/* 4 or 8 */
   uint next_number_key_offset;

sql/unireg.cc

@@ -354,8 +354,12 @@ static bool pack_header(uchar *forminfo, enum db_type table_type,
 					   MTYP_NOEMPTY_BIT);
       no_empty++;
     }
-    if ((MTYP_TYPENR(field->unireg_check) == Field::TIMESTAMP_FIELD ||
+    /* 
-	 f_packtype(field->pack_flag) == (int) FIELD_TYPE_TIMESTAMP) &&
+      We mark first TIMESTAMP field with NOW() in DEFAULT or ON UPDATE 
+      as auto-update field.
+    */
+    if (field->sql_type == FIELD_TYPE_TIMESTAMP &&
+        MTYP_TYPENR(field->unireg_check) != Field::NONE &&
 	!time_stamp_pos)
       time_stamp_pos=(int) field->offset+1;
     length=field->pack_length;