Daniel

1. at any transaction level. this is storage engine, innodb has row lock.

2. create table in mysql. create table row_lock (id integer primary key,text varchar(200));

3. insert a new data in row_lock; insert into row_lock values(1,’first’);

session 1	session 2
insert into row_lock values(1,’first’);
	select * from row_lock; result:(1,’first’)
start transaction;
	start transaction;
update row_lock set text = ‘second’ where id = 1;
Rows matched: 1 Changed: 0 Warnings: 0
	update row_lock set text = ‘third’ where id = 1;
	result: waiting…
commit;
Query OK, 0 rows affected (0.00 sec)
	Query OK, 0 rows affected (4.94 sec[waiting time])
	commit;
	Query OK, 0 rows affected (0.00 sec)