drop table if exists t1;
CREATE TABLE t1 (
gesuchnr int(11) DEFAULT '0' NOT NULL,
benutzer_id int(11) DEFAULT '0' NOT NULL,
PRIMARY KEY (gesuchnr,benutzer_id)
) type=ISAM;
replace into t1 (gesuchnr,benutzer_id) values (2,1);
replace into t1 (gesuchnr,benutzer_id) values (1,1);
replace into t1 (gesuchnr,benutzer_id) values (1,1);
alter table t1 type=myisam;
replace into t1 (gesuchnr,benutzer_id) values (1,1);
alter table t1 type=heap;
replace into t1 (gesuchnr,benutzer_id) values (1,1);
drop table t1;
create table t1 (a tinyint not null auto_increment primary key, b char(20));
insert into t1 values (126,"first"),(0,"last");
insert into t1 values (0,"error");
Duplicate entry '127' for key 1
replace into t1 values (0,"error");
Duplicate entry '127' for key 1
replace into t1 values (126,"first updated");
select * from t1;
a	b
126	first updated
127	last
drop table t1;