drop table if exists t1; create table t1 (a int not null); insert into t1 values (1); insert into t1 values (a+2); insert into t1 values (a+3); insert into t1 values (4),(a+5); select * from t1; a 1 2 3 4 5 drop table t1; create table t1 (id int not null auto_increment primary key, username varchar(32) not null, unique (username)); insert into t1 values (0,"mysql"); insert into t1 values (0,"mysql ab"); insert into t1 values (0,"mysql a"); insert into t1 values (0,"r1manic"); insert into t1 values (0,"r1man"); drop table t1; create table t1 (a int not null auto_increment, primary key (a), t timestamp, c char(10) default "hello", i int); insert into t1 values (default,default,default,default), (default,default,default,default), (4,0,"a",5),(default,default,default,default); select a,t>0,c,i from t1; a t>0 c i 1 1 hello NULL 2 1 hello NULL 4 0 a 5 5 1 hello NULL truncate table t1; insert into t1 set a=default,t=default,c=default; insert into t1 set a=default,t=default,c=default,i=default; insert into t1 set a=4,t=0,c="a",i=5; insert into t1 set a=5,t=0,c="a",i=null; insert into t1 set a=default,t=default,c=default,i=default; select a,t>0,c,i from t1; a t>0 c i 1 1 hello NULL 2 1 hello NULL 4 0 a 5 5 0 a NULL 6 1 hello NULL drop table t1; create table t1 (sid char(20), id int(2) NOT NULL auto_increment, key(sid, id)); insert into t1 values ('skr',NULL),('skr',NULL),('test',NULL); select * from t1; sid id skr 1 skr 2 test 1 drop table t1; drop database if exists foo; create database foo; use foo; create table t1 (c int); insert into foo.t1 set foo.t1.c = '1'; drop database foo;