mysql日常積累(一)

2021-08-14 01:33:39 字數 2063 閱讀 7994

知識點:

1、substring_index:欄位中擷取

2、mysql.help_topic:自帶資料庫表

3、inet_aton:ip轉換整型

4、length:是計算欄位的長度乙個漢字是算三個字元,乙個數字或字母算乙個字元

5、replace:替換

select sum(r.in_bytes) as in_bytes, sum(r.out_bytes) as out_bytes, sum(r.total_bytes) as total_bytes,

r.sum_inbytes, r.sum_outbytes,r.sum_totalbytes,

r.group_name, r.group_id

from

(select datas.id,datas.ip_begin,datas.in_bytes,datas.out_bytes,

datas.total_bytes,datas.sum_inbytes, datas.sum_outbytes,datas.sum_totalbytes, groups.group_name, groups.group_id

from

(select u.id,u.ip_address as ip_begin,u.in_bytes,u.out_bytes,u.total_bytes,sum_inbytes,

sum_outbytes,sum_totalbytes from

(select u.id,u.ip_address,u.in_bytes,u.out_bytes,u.total_bytes

from yf_flow_users u

where record_time >= '2017-12-18 16:00'

and record_time < '2017-12-25 16:00'

)as u,

(select

sum(sum_inbytes) as sum_inbytes,sum(sum_outbytes) as

sum_outbytes,sum(sum_totalbytes) as sum_totalbytes from

(select sum_inbytes,sum_outbytes,sum_totalbytes

from yf_flow_users

where

record_time >= '2017-12-18 16:00'

and record_time < '2017-12-25 16:00'

group by sum_inbytes,sum_outbytes,sum_totalbytes

)as s)as sum

order by

total_bytes desc) datas,

(select substring_index(ips,'-',1) as start_ip,

substring_index(substring_index(ips,'-',2),'-',-1) as end_ip, g.group_name, g.group_id from 

(select substring_index(substring_index(t.ip_begin,',', b.help_topic_id + 1), ',', -1) as ips, t.name as group_name, t.id as group_id

from yf_flow_group t join mysql.help_topic b on b.help_topic_id < (length(t.ip_begin) - length(replace(t.ip_begin, ',', '')) + 1)) g) groups

where inet_aton(datas.ip_begin) >=  inet_aton(groups.start_ip)

and inet_aton(datas.ip_begin) <=  inet_aton(groups.end_ip)) r

group by r.group_id, r.group_name,r.sum_inbytes, r.sum_outbytes,r.sum_totalbytes

order by total_bytes desc

日常積累C

預設建構函式準確來說就是在呼叫時不需要傳入形參的建構函式。c 11 在原有提供預設建構函式 賦值建構函式 複製賦值運算子和析構函式的基礎上增加移動建構函式和移動複製運算子。預設建構函式原型 someclass someclass const someclass 移動建構函式原型 someclass ...

linux命令日常積累

壓縮命令 命令格式 tar zcvf 壓縮檔案名.tar.gz 被壓縮檔案名 1 cd 檔案目錄 切換到檔案目錄 2 ls 檢視一下檔案 3 tar zcvf aa 壓縮檔案名 tar.gz bb 要備份的檔名 ear 可先切換到當前目錄下。壓縮檔案名和被壓縮檔案名都可加入路徑。解壓縮命令 命令格式...

Qt之日常積累

qt獲取qdatatimeedit的值 qdatetime datetimes qdatetimeedit time new qdatetimeedit qdatetime currentdatetime datetimes time datetime 讀取qtextedit的值 qstring c...