一、from_unixtime 和unix_timestamp 如下：
1， select
from_unixtime(unix_timestamp(data_datetime)-unix_timestamp(data_datetime)%300) as tm,
bussinessname,
sum(upload_size_bt) as band,
count(1)
from dcdn_flume.livetraceplay ori
select
from_unixtime(stime-stime%300) as tm,
server_ip,
client_isp,
client_pro,
bt
from dcdn_mdl.f_i5_live_panda_kandun_idc
2，from_unixtime(starttime)= '2017-6-19 19:50:00' and from_unixtime(starttime) = '2017-6-19 19:55:00'
3，select (case when substr(domain,1,1)='d' then trunc(cast(stime+28800 as timestamp), 'MI') else trunc(cast(stime as timestamp), 'MI') end) as sstime,
domain,
app,
stream,
remoteip cip,
localip sip,
sum(1) cnt,
avg(avg_frame_rate) avg_frame
from live_orig.o_live_mixcdn_trace
where ptime>=20180228000000
and ptime< 20180301000000
and ((substr(domain,1,1)='d' and stime + 28800 >= unix_timestamp('{st}') and stime + 28800 < unix_timestamp('{et}'))
or (substr(domain,1,1) !='d' and stime >= unix_timestamp('{st}') and stime < unix_timestamp('{et}')))
and logtype='Play_State'
and stime is not null
and localip is not null
and localip !=''
group by sstime,domain,app,stream,remoteip,localip
4、AND tm >= unix_timestamp(cast('{st}' as TIMESTAMP)- interval 8 hours )
AND tm < unix_timestamp(cast('{et}' as TIMESTAMP)- interval 8 hours )
二、cast as
當將非數字類型的 char、nchar、varchar 或 nvarchar 數據轉換為 int、float、numeric 或 decimal時，SQL Server 將返回錯誤信息。
當將空字符串 (" ") 轉換為 numeric 或 decimal 時，SQL Server 也將返回錯誤信息