--获得指定格式的时间
SELECT DATE_FORMAT(NOW(), '%Y%m%d%H%I%S');
--获得随机数
SELECT round(round(rand(),4)*10000);
--字符串拼接
select CONCAT(CONCAT(a.big_type,a.type,a.code),DATE_FORMAT(NOW(), '%Y%m%d%H%I%S'),round(round(rand(),4)*10000)) from sc_chshbjlb a
--更新
update sc_bjgl b set b.citypartcode= (select CONCAT(CONCAT('#{type_code}','#{citypart_apl}'),DATE_FORMAT(NOW(), '%Y%m%d%H%I%S'),round(round(rand(),4)*10000)))
where b.id='#{id}';
--更新
update sc_chshbjlb set type = (case type when 'p' then 'point'
when 'l' then 'line'
when 'a' then 'polygon'
else '' END);
--修改字段的长度
ALTER TABLE "public"."tsac_orderinfo"
ALTER COLUMN "remark" TYPE varchar(1000);
--创建id自增的表:
drop table `sc_incrementtab`;
CREATE TABLE `sc_incrementtab` (
`in_id` int(11) NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`in_id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;
其中,AUTO_INCREMENT为初始值,目前为 1。
每次往自增表中插入数据时,用如下方式插入:
insert into sc_incrementtabvalues(null);,值设为null。
数据库会自动+1的。
-- 左补齐,右补齐
lpad(obligatea,6,'0')
rpad(obligatea,6,'0')
--查找重复数据
select xm,count(xm) from sc_rkjbxxnew where 1=1 group by xm having count(xm) >1;
select xm,count(xm)
from sc_rkjbxxnew
where xm in (select xm from sc_rkjbxxnew group by xm having count(xm) >= 2)
GROUP BY xm;
--根据查询结果,更新数据表的数据字段
update t_apprecord a set datetime = (select '2017-04-19'||substr(to_char(b.datetime),-9)
from t_apprecord b where b.datetime < '1990-01-01 08:00:37'
and a.prjid=b.prjid
and a.userid=b.userid
and a.signtag= b.signtag
and a.lat=b.lat
and a.lon=b.lon
and a.datetime=b.datetime)
where a.datetime < '1990-01-01 08:00:37';