#1.创建test表（测试表）。
drop table if exists test; create table test( id int primary key auto_increment, c1 varchar(10), c2 varchar(10), c3 varchar(10), c4 varchar(10), c5 varchar(10) ) ENGINE=INNODB default CHARSET=utf8; insert into test(c1,c2,c3,c4,c5) values(\'a1\',\'a2\',\'a3\',\'a4\',\'a5\'); insert into test(c1,c2,c3,c4,c5) values(\'b1\',\'b2\',\'b3\',\'b4\',\'b5\'); insert into test(c1,c2,c3,c4,c5) values(\'c1\',\'c2\',\'c3\',\'c4\',\'c5\'); insert into test(c1,c2,c3,c4,c5) values(\'d1\',\'d2\',\'d3\',\'d4\',\'d5\'); insert into test(c1,c2,c3,c4,c5) values(\'e1\',\'e2\',\'e3\',\'e4\',\'e5\');