===================從數據庫中取數據導出到execl文檔中=====================
連接數據庫：mysql -h x.x.x.x -u ceshi -plianxi
show databases;
use 你的庫名
show tables;
select 指標1,指標2,指標3,timestamp,from_unixtime(timestamp) from 表名 where 表中的某個指標 in ("指標中的某個具體的值") and timestamp>=unix_timestamp("1970-05-01 00:00:00") and timestamp<unix_timestamp("1970-06-01 00:00:00") into outfile "/tmp/temp.csv";
例：我從liuliang表中導出指定機器x.x.x.x的上下行流量數據到文件/tmp/temp-liuliang.csv中
select hostname,inbps,outbps,timestamp,from_unixtime(timestamp) from liuliang where hostname in ("x.x.x.x") and timestamp>=unix_timestamp("2020-02-18 00:00:00") and timestamp<unix_timestamp("2020-02-19 00:00:00") into outfile "/tmp/temp-liuliang.csv";
導出數據到文件后，需要將文件中的空格間隔替換為逗號："," （要確保文件中的空格全部被替換了，否則一直執行如下的命令）
vim命令打開文件后直接輸入內容--->: :%s/\s\+/,/
: :%s+;+,+ 此格式為將分號";"替換為逗號","