select a.fd_meter_joint as 表号,a.fzdate as 最后一次时间,a.data as 最后一次数据,b.fzdate as 倒数第二次时间,b.data as 倒数第二次数据 from (
select * from freezedata as tem where fzdate=(select max(fzdate) from freezedata where fd_meter_joint=tem.fd_meter_joint)
) as a left join (
select * from freezedata as tem where fzdate=(select max(fzdate) from freezedata where fd_meter_joint=tem.fd_meter_joint and fzdate<>(select max(fzdate) from freezedata where fd_meter_joint=tem.fd_meter_joint))
) as b on a.fd_meter_joint=b.fd_meter_joint
select * from freezedata as tem where fzdate=(select max(fzdate) from freezedata where fd_meter_joint=tem.fd_meter_joint)
) as a left join (
select * from freezedata as tem where fzdate=(select max(fzdate) from freezedata where fd_meter_joint=tem.fd_meter_joint and fzdate<>(select max(fzdate) from freezedata where fd_meter_joint=tem.fd_meter_joint))
) as b on a.fd_meter_joint=b.fd_meter_joint
from(
select 表号=fd_meter_joint,最后一次读数=data from freezedata
where joint=(select max(joint) from freezedata where fzdate=(select max(fzdate) from freezedata))
) a inner join b(
select 表号=fd_meter_joint,倒数第二次读数=data from freezedata
where joint=(select max(joint) from freezedata where fzdate=(select max(fzdate) from freezedata where fzdate<>(select max(fzdate) from freezedata)))
) on a.表号=b.表号
from(
select 表号=fd_meter_joint,最后一次读数=data from freezedata
where joint=(select max(joint) from freezedata)
) a inner join b(
select 表号=fd_meter_joint,倒数第二次读数=data from freezedata
where joint=(select max(joint) from freezedata where joint not in(select max(joint) from freezedata))
) on a.表号=b.表号
select a.表号,a.最后一次读数,b.倒数第二次读数
from(
select 表号=fd_meter_joint,最后一次读数=data from freezedata
where joint=(select max(joint) from freezedata where fd_meter_joint=a.fd_meter_joint and fzdate=(select max(fzdate) from freezedata where fd_meter_joint=a.fd_meter_joint))
) a inner join b(
select 表号=fd_meter_joint,倒数第二次读数=data from freezedata
where joint=(select max(joint) from freezedata where fd_meter_joint=b.fd_meter_joint and fzdate=(select max(fzdate) from freezedata where fd_meter_joint=b.fd_meter_joint and fzdate<>(select max(fzdate) from freezedata where fd_meter_joint=b.fd_meter_joint)))
) on a.表号=b.表号
方法2.
select a.表号,a.最后一次读数,b.倒数第二次读数
from(
select 表号=fd_meter_joint,最后一次读数=data from freezedata
where joint=(select max(joint) from freezedata where fd_meter_joint=a.fd_meter_joint)
) a inner join b(
select 表号=fd_meter_joint,倒数第二次读数=data from freezedata
where joint=(select max(joint) from freezedata where fd_meter_joint=b.fd_meter_joint and joint not in(select max(joint) from freezedata where fd_meter_joint=a.fd_meter_joint))
) on a.表号=b.表号
select * from freezedata as tem where fzdate=(select max(fzdate) from freezedata where fd_meter_joint=tem.fd_meter_joint)
) as a left join (
select * from freezedata as tem where fzdate=(select max(fzdate) from freezedata where fd_meter_joint=tem.fd_meter_joint and fzdate<>(select max(fzdate) from freezedata where fd_meter_joint=tem.fd_meter_joint))
) as b on a.fd_meter_joint=b.fd_meter_joint谁能把这个语句中的left join去掉,改成表连接,在其他数据库中不支持这个关键字
select * from freezedata as tem where fzdate=(select max(fzdate) from freezedata where fd_meter_joint=tem.fd_meter_joint)
) as a left join (
select * from freezedata as tem where fzdate=(select max(fzdate) from freezedata where fd_meter_joint=tem.fd_meter_joint and fzdate<>(select max(fzdate) from freezedata where fd_meter_joint=tem.fd_meter_joint))
) as b on a.fd_meter_joint=b.fd_meter_joint谁能把这个语句中的left join去掉,改成表连接,在其他数据库中不支持这个关键字