1drop table if exists t1; 2create table t1 (a int not null auto_increment,b int, primary key (a)) engine=heap auto_increment=3; 3insert into t1 values (1,1),(NULL,3),(NULL,4); 4delete from t1 where a=4; 5insert into t1 values (NULL,5),(NULL,6); 6select * from t1; 7a b 81 1 93 3 105 5 116 6 12delete from t1 where a=6; 13replace t1 values (3,1); 14ALTER TABLE t1 add c int; 15replace t1 values (3,3,3); 16insert into t1 values (NULL,7,7); 17update t1 set a=8,b=b+1,c=c+1 where a=7; 18insert into t1 values (NULL,9,9); 19select * from t1; 20a b c 211 1 NULL 223 3 3 235 5 NULL 248 8 8 259 9 9 26drop table t1; 27create table t1 ( 28skey tinyint unsigned NOT NULL auto_increment PRIMARY KEY, 29sval char(20) 30) engine=heap; 31insert into t1 values (NULL, "hello"); 32insert into t1 values (NULL, "hey"); 33select * from t1; 34skey sval 351 hello 362 hey 37select _rowid,t1._rowid,skey,sval from t1; 38_rowid _rowid skey sval 391 1 1 hello 402 2 2 hey 41drop table t1; 42