load data local infile ‘D:\\文件名.txt‘ into table 表名 fields terminated by ‘\t‘;
2：插入数据后查询显示乱码，解决方案：set character set_results=utf-8;
3：多表多外键数据查询
select * from userinfo,usertype,usercert where userinfo.certid=usercert.certid and userinfo.typeid=usertype.typeid limit ?,?;
select * from userinfo,usertype,usercert where userinfo.certid=usercert.certid and userinfo.typeid=usertype.typeid and userinfo.userid=140950223 and password=55555 limit ?,?;
