The Mysql2 gem is meant to serve the extremely common use-case of connecting, querying and iterating on results. Some database libraries out there serve as direct 1:1 mappings of the already complex C ...

mysql 在存储数据的时候会根据当前数据库的字符集来校验数据，发现非法数据时会抛弃其后续数据。 当表的字符集是utf8_general_ci 时，测试SQL： Insert into table values (concat('ab', 0x80, 'cd'))，因为0x80不是有效的UTF-8字符，所以只有ab被写入数据库中，cd会被截断。

MySQL supports two types: Virtual: calculated when queried and not stored on disk. Stored: calculated on insert or update and saved on disk. Virtual columns save storage, while Stored columns avoid ...