Never use utf8 in MySQL — always use utf8mb4 instead
MySQL’s utf8mb4 纔是對應UTF-8編碼
MySQL’s utf8 不支持編碼4位bytes的字符,只支持1-3位,有安全風險
鏈接:https://medium.com/@adamhooper/in-mysql-never-use-utf8-use-utf8mb4-11761243e434
Never use utf8 in MySQL — always use utf8mb4 instead
MySQL’s utf8mb4 纔是對應UTF-8編碼
MySQL’s utf8 不支持編碼4位bytes的字符,只支持1-3位,有安全風險
鏈接:https://medium.com/@adamhooper/in-mysql-never-use-utf8-use-utf8mb4-11761243e434
mysql delele table語句使用別名: 語法: delete t from table t where t.column = value;
UNION用的比較多union all是直接連接,取到得是所有值,記錄可能有重複 union 是取唯一值,記錄沒有重複 1、UNION 的語法如下: [SQL 語句 1] UNION [SQL