简单常用的SQL语句

1 删除AB之间的数据

delete from 表名 where 列名 between A and B

2 在原有数据上修改

带锅炉
select bianhao,substr(bianhao, 1,length(bianhao)-2) || 'XG' from gongchengxx WHERE bianhao like '%G.&'

update gongchengxxset bianhao = substr(bianhao, 1,length(bianhao)-2) || 'XG' WHERE bianhao like '%G.&'

不带锅炉
select bianhao,substr(bianhao, 1,length(bianhao)-1) || 'X' from gongchengxx WHERE bianhao like '%G.'

update gongchengxxset bianhao = substr(bianhao,1,length(bianhao)-1) || 'X' WHERE bianhao like '%G.'

查询当天数据
SimpleDateFormat sm = new SimpleDateFormat("yyyy-MM-dd");
Date date = new Date();
String time= sm.format(date);
String sql = "select * from alarms where to_char(time,'yyyy-MM-dd') ='"+time+"' order by time desc";
alarmsList = session.createSQLQuery(sql).addEntity(Alarms.class).list();
条件查询
alarmsList = session.createCriteria(Alarms.class)
.add(Example.create(alarms))
.addOrder(Order.desc("alarmid"))
.list();
ID查询一条数据
alarms = (Alarms) session.get(Alarms.class,id);
添加 修改 删除
session.save(alarms); session.update(alarms); session.delete(alarm);
查询3个结果集
String sql = "select * from (select count(*) from messagenews)," +
"(select count(state) from messagenews where state = 'A'and gtime >"+"'"+time2+"')," +
"(select count(velocityfri) from messagenews where velocityfri <> '00110' and gtime >"+"'"+time2+"')";
list = session.createSQLQuery(sql).list();
num = (Object[]) list.get(0); //carNum为实体类
carNum.setSum(Integer.valueOf(String.valueOf(num[0])).intValue());
carNum.setOnNum(Integer.valueOf(String.valueOf(num[1])).intValue());
carNum.setRunNum(Integer.valueOf(String.valueOf(num[2])).intValue());


内连接
A: select d.departmentid,d.departname ,c.carid ,c.departmentid
from department d,car c
where d.departmentid = c.departmentid
and d.departmentid >10;
B;
select i.imtime,i.carid,i.overload,d.departname
from department d,images i,car c
where i.carid = c.carid and c.departmentid = d.departmentid;


C:
select i.imtime,i.carid,c.carnum,i.overload,d.departname,i.imageid from department d,images i,car c
where i.carid = c.carid and c.departmentid = d.departmentid
and substr(i.imtime,0,10) >='2012-11-10' and substr(i.imtime,0,10) <='2012-11-15';

















左连接
select d.departmentid,d.departname ,c.carid ,c.departmentid
from department d
left outer join car c
on d.departmentid = c.departmentid
order by d.departmentid;
右连接
select d.departmentid,d.departname ,c.carid ,c.departmentid
from department d
right join car c
on d.departmentid = c.departmentid
order by d.departmentid;








select c.carid,c.owner,c.telnub, m.ldate,m.velocityfri,m.meter,m.direction,m.licheng,m.io,m.state




//查询一个表里的各个商品的平均价低于2元的商品名称
select * from(
select name,avg(进价) 平均价
from 商品表
group by 名称 having count(名称) > 1
) where 平均价 < 2






触发器


A：
在执行sql语句之前触发，
create or replace trigger tr_before_insert_employee
before insert
on t_employees
for each row
begin
:new.work_years :=0;
end;