linux命令导入mysql脚本文件到指定数据库
mysql -h192 168 43 231 -uroot -p123456 -P3306 -Dworkhour -e "source tiger shell workhour sql "
mysql存储过程（自定义函数）1337-Variable or condition declaration after cursor or handler declaration
创建mysql自定义函数时，提示错误[Err] 1337 - Variable or condition declaration after cursor or handler declaration 原因：定义变量必须放在游标之前，而我放在了游标后面，所以导致此错误 解决：变量定义放在游标定义之前
mysql存储过程（自定义函数之）declare continue handler for sqlstate '02000' set
DECLARE CONTINUE HANDLER FOR SQLSTATE 02000 SET s=1; 当fetch游标到了数据库表格最后一行的时候，设置s=1
[Err] 1418 - This function has none of DETERMINISTIC, NO SQL, or READS SQL DATA in its declaration and binary logging is enabled
This function has none of DETERMINISTIC, NO SQL, or READS SQL DATA in its declaration and binary logging is enabled (you *might* want to use the less safe log_bin_trust_function_creators variable)
1320 - No RETURN found in FUNCTION techmanage.project
1320 - No RETURN found in FUNCTION techmanage project
mysql报错：Column count doesn't match value count at row 1
msyql执行insert插入语句，提示Column count doesn t match value count at row 1错误
Mysql关联两张表时，产生错误提示Illegal mix of collations
Mysql关联两张表时，产生错误提示Illegal mix of collations，先用工具把数据库、两张表的编码方式改变，需要改变字段的编码方式。
MySQL8文档存储document store（nosql加sql等于msyql8 document store）
MySQL Document Store允许开发人员使用SQL关系表和JSON集合，本质上就是实现了一套 MongoDB
MongoDB 定时TTL索引过期自动删除数据
MongoDB 定时TTL索引过期自动删除数据，
column count does`t match value count
column count does`t match value count就是列数与第1行的值计数不匹配