MySQL转储文件并注释掉行

问题描述：

我在MySQL .sql文件(与phpMyAdmin转储)的顶部有这些行:

I have these lines at the top of a MySQL .sql file (dumped with phpMyAdmin):

/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8 */;

但是它们似乎都被注释掉了.那么，当文件重新加载到数据库中时，MySQL将忽略它们吗?如果是这样，为什么还要生成这些行呢?

But they all seem to be commented out. So will MySQL ignore them when the file is loaded back into a database? If so, why generate these lines at all?

答

这些是针对特定版本的mySQL的条件注释.

These are conditional comments aimed at certain versions of mySQL.

来自此处:

MySQL版本特定注释以/*!
并以*/
版本号始终为5位数字
版本号采用主发行版号的格式，次要版本号，主版本号为1位数的修订号次要版本和修订版本为2位数，左后加0的数字
特定于版本的注释将定位到等于或高于该版本的任何版本列出的版本号

MySQL version specific comments start with /*!
And end with */
Version numbers are always 5 digits
Version numbers are in the format major release number, minor release number, revision number with the major being 1 digit and the minor and revision being 2 digits left-padded with 0’s
Version specific comments will target any version equal to or higher than the version number listed

MySQL转储文件并注释掉行

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