linux命令導入mysql腳本文件到指定數據庫
mysql -h192 168 43 231 -uroot -p123456 -P3306 -Dworkhour -e "source tiger shell workhour sql "
mysql存儲過程（自定義函數）1337-Variable or condition declaration after cursor or handler declaration
創建mysql自定義函數時，提示錯誤[Err] 1337 - Variable or condition declaration after cursor or handler declaration 原因：定義變量必須放在游標之前，而我放在了游標后面，所以導致此錯誤 解決：變量定義放在游標定義之前
mysql存儲過程（自定義函數之）declare continue handler for sqlstate '02000' set
DECLARE CONTINUE HANDLER FOR SQLSTATE 02000 SET s=1; 當fetch游標到了數據庫表格最后一行的時候，設置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報錯：Column count doesn't match value count at row 1
msyql執行insert插入語句，提示Column count doesn t match value count at row 1錯誤
Mysql關聯兩張表時，產生錯誤提示Illegal mix of collations
Mysql關聯兩張表時，產生錯誤提示Illegal mix of collations，先用工具把數據庫、兩張表的編碼方式改變，需要改變字段的編碼方式。
MySQL8文檔存儲document store（nosql加sql等于msyql8 document store）
MySQL Document Store允許開發人員使用SQL關系表和JSON集合，本質上就是實現了一套 MongoDB
MongoDB 定時TTL索引過期自動刪除數據
MongoDB 定時TTL索引過期自動刪除數據，
column count does`t match value count
column count does`t match value count就是列數與第1行的值計數不匹配