mysql 字串号以逗号分隔，分隔后第个字符加单引号，然后再拼接起来，字符间用逗号...
MySQL中的字段拼接 concat() concat_ws() group_concat()函数
https://www.cnblogs.com/mianbaoshu/p/11821112.html
给字段加上号号，并拼接起来。
SELECT sex FROM `t1`
select replace(concat('''',sex,''''),',',''',''') from t1
select concat('''',sex,'''') from t1
select group_concat(concat('''',sex,'''')) from t1 group by address;
MySQL之Field‘***’doesn’t have a default value错误解决办法
https://www.cnblogs.com/lxwphp/p/9054971.html
ALTER TABLE `user` MODIFY COLUMN create_time datetime NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间';
ALTER TABLE `user` MODIFY COLUMN `update_time` datetime NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '更新时间';
create_time 设置 CURRENT_TIMESTAMP属性
update_time 设置 ON UPDATE CURRENT_TIMESTAMP属性
https://blog.csdn.net/ju_362204801/article/details/105969557
修改MYSQL的默认连接时长
show global variables like 'wait_timeout';
设置成10小时;
set global wait_timeout=36000;
重新开始新binary log
flush logs
mysqladmin flush-logs
查看过期时间
show variables like 'expire_logs_days';
设置过期时间
set global expire_logs_days=7;
清除某个时间的日志
purge binary logs before '2021-01-27 10:00:51';
删除mysql日志文件
第一步：登陆进入mysql，并使用 show binary logs; 查看日志文件。
第二步：查看正在使用的日志文件：show master status;
当前正在使用的日志文件是mysql-bin.000005，那么删除日志文件的时候应该排除掉该文件。 删除日志文件的命令：purge binary logs to ‘mysql-bin.000005’; mysql> purge binary logs to 'mysql-bin.000005';
https://blog.csdn.net/weixin_33895657/article/details/92248743
https://blog.csdn.net/leo__1990/article/details/90166934
自动清理mysql binlog
mysql master status_开发HTTP接口，获取MySQL show master status信息
https://blog.csdn.net/weixin_32532145/article/details/113206127
https://www.cnblogs.com/firmament/p/8493324.html
修改mysql的时间/时区
https://www.cnblogs.com/jwentest/p/8610038.html
查看时区
show variables like "%time_zone%";
修改时区
set global time_zone = '+8:00'; ##修改mysql全局时区为北京时间，即我们所在的东8区
set time_zone = '+8:00'; ##修改当前会话时区
flush privileges; #立即生效
ERROR 1197 (HY000): Multi-statement transaction required more than ‘max_binlog_cache_size‘ bytes of
https://blog.csdn.net/eagle89/article/details/109047720
max_binlog_cache_size设置不当
用SQL命令查看Mysql数据库大小 统计数据库空间占用
https://www.cnblogs.com/chenzechao/p/11433083.html
pymysql连接数据库报错：
TypeError: init() takes 1 positional argument but 5 positional arguments
https://blog.csdn.net/qq_45293654/article/details/114290702
pymysql在1.0以后的版本 无法使用 db = pymysql.connect(“localhost”,“root”,“root”,“testdb” ) 需要修改为 db = pymysql.connect(host=“localhost”, user=“root”, password=“root”, database=“testdb”) 这样就可以连接上MySQL数据库了
mysql5.7导入txt文件_MySQL导入txt文件
https://blog.csdn.net/weixin_31261145/article/details/114824305
mysql导出导入文本文件的几种方式总结
https://blog.csdn.net/eagle89/article/details/105976515
向MySQL数据库表内导入txt和csv文件数据
https://blog.csdn.net/u013378642/article/details/81220809
mysql 导入数据load data infile用法 https://blog.csdn.net/u013818525/article/details/79728882
LOAD DATA local INFILE '/root/test.txt' INTO TABLE flow_test FIELDS TERMINATED by '|' LINES TERMINATED BY '\n';
load data local infile "/root/flow-utf8.txt" into table flow_info FIELDS TERMINATED BY '|' LINES TERMINATED BY '\n' (ncl_code_one,reg_number,flow_name,flow_date,trial_num);
mysql 导入数据load data infile用法
https://blog.csdn.net/u013818525/article/details/79728882
https://www.cnblogs.com/xj2015/p/6656287.html
load data local infile "/tmp/company_19970801_000.dat" into table company_38 FIELDS TERMINATED BY '\t' LINES TERMINATED BY '\n' (id,base,name,legal_person_id,legal_person_name,legal_person_type,reg_number,company_type,company_org_type,reg_location,establish_time,from_time,to_time,business_scope,reg_institute,approved_time,reg_status,reg_capital,actual_capital,org_number,org_approved_institute,flag,parent_id,update_time,list_code,ownership_stake,source_flag,name_suffix,usc_code,gsb_new_company_name_id,gsb_english_company_name,taxpayer_identification_number,app_time,crawled_time,create_time,flag);
mysql -h'127.0.0.1' -u'username' -p'passwd' --default-character-set=utf8 -e"load data local infile fileName into table $tableName fields terminated by ',' lines terminated by '\n' (col1,col2,col3)"
Navicat 设计表自增从 1 开始
https://www.cnblogs.com/kingsonfu/p/9867178.html
https://www.likecs.com/show-203515515.html
设计表--》选项--》自运递增
或者sql语句
修改自增ID的起始值
alter table users AUTO_INCREMENT=10000;
mysql8.0已支持该regex_replace函数
https://blog.csdn.net/qq_43472877/article/details/119275106?utm_medium=distribute.pc_relevant.none-task-blog-2~default~baidujs_baidulandingword~default-0-119275106-blog-103183360.pc_relevant_multi_platform_whitelistv1_exp2&spm=1001.2101.3001.4242.1&utm_relevant_index=2
mysql5.7实现regex_replace正则替换功能
https://blog.csdn.net/qq_35861801/article/details/103183360
自用MySQL5.7中的正则表达式替换函数regxp_replace_all
https://blog.csdn.net/weixin_39461443/article/details/125199226
MySql -- 不存在则插入，存在则更新或忽略
https://blog.csdn.net/wdquan19851029/article/details/125068600
https://blog.csdn.net/qq_40301202/article/details/124136242
mysql分组取最大(最小、最新、前N条)条记录
https://www.cnblogs.com/fps2tao/p/9041175.html
http://www.manongjc.com/detail/61-mdqmwijslhxwsrk.html
https://www.cnblogs.com/rgsn/p/15979408.html
