1.日志格式
'"$remote_addr"\t"$http_x_forwarded_for"\t"$remote_user"\t"$time_local"\t"$request"\t"$request_time"\t"$status"\t"$body_bytes_sent"\t"$upstream_addr"\t"$upstream_response_time"\t"$http_referer"\t"$http_user_agent"' 宁静为篱 淡雅为阶 心自有桃源
1.日志格式
'"$remote_addr"\t"$http_x_forwarded_for"\t"$remote_user"\t"$time_local"\t"$request"\t"$request_time"\t"$status"\t"$body_bytes_sent"\t"$upstream_addr"\t"$upstream_response_time"\t"$http_referer"\t"$http_user_agent"' Nginx的return关键字属于HttpRewriteModule模块:
语法:return http状态码
默认值:无
上下文:server,location,if
该指令将结束执行直接返回http状态码到客户端.
支持的http状态码:200, 204, 400, 402-406, 408, 410, 411, 413, 416 , 500-504,还有非标准的444状态码. 

2019-08-03 08:30:26 星期六
# cat /etc/redhat-release
CentOS release 6.5 (Final)
# mysql -V
mysql Ver 14.14 Distrib 5.6.17, for linux-glibc2.5 (x86_64) using EditLine wrapper
mysql.cnf配置
slow_query_log=1
long_query_time=1
slow_query_log_file=/usr/local/mysql/data/slow-query.log 2019-08-02 14:54:34 星期五
1、不为空
Select * From table_name Where id<>''
Select * From table_name Where id!=''2、为空
Select * From table_name Where id=''
Select * From table_name Where ISNULL(id)具体情况具体分析,如果字段是char和varchar型用 id=''可以;如果是int型用 ISNULL好些
参考文档
https://www.cnblogs.com/Liang-Haishan216/p/8308733.html