Q:为什么要用utf8mb4
A:utf8mb4可以直接保存emoji字符

MySQL修改字符集

// 数据表编码改为utf8mb4
function to_utf8mb4()
{
	$database = config("database.database");
	$sql = "ALTER DATABASE `{$database}` CHARACTER SET `utf8mb4` COLLATE `utf8mb4_general_ci`;"; //数据库
	// Db::execute($sql);
	echo $sql;
	$lists = Db::getTables();
	foreach ($lists as $key => &$value) {
		Db::execute("ALTER TABLE `{$value}` CONVERT TO CHARACTER SET `utf8mb4` COLLATE `utf8mb4_general_ci`;"); //数据表
		$fields = Db::getFields($value);
		foreach ($fields as $key1 => &$value1) {
			if (mb_strpos(strtolower($value1["type"]), "char") !== false) {
				Db::execute("ALTER TABLE `{$value}` CHANGE `{$value1["name"]}` `{$value1["name"]}` {$value1["type"]} CHARACTER SET `utf8mb4` COLLATE `utf8mb4_general_ci` DEFAULT '{$value1["default"]}';"); //字段
			}
		}
	}
}

thinkPHP5.0框架

// 数据库编码默认采用utf8
'charset' => 'utf8',

新的

// 数据库编码默认采用utf8
'charset' => 'utf8mb4',

修改之后可以直接存储emoji

普通的utf8字符

emoji

参考文章
https://blog.csdn.net/qq_50573146/article/details/125177260