SET NAMES UTF8的具體作用是什麼?

為了防止亂碼，我在為db設罷了好幾個字元集：

<code>        mysqli_query($db,"SET NAMES UTF8");
        mysqli_query($db,"set character_set_client=utf8");
        mysqli_query($db,"set character_set_connection=utf8");
        mysqli_query($db,"set character_set_results=utf8");</code>

不過看到一篇文章是這麼說的：
http://zhangxugg-163-com.iteye.com/blog/1835721

按上面的描述，一條SET NAMES UTF8是不是就已經等於set character_set_client=utf8; set character_set_connection=utf8; set character_set_results=utf8; 大家討論下

.`

回覆內容：

為了防止亂碼，我在為db設罷了好幾個字元集：

<code>        mysqli_query($db,"SET NAMES UTF8");
        mysqli_query($db,"set character_set_client=utf8");
        mysqli_query($db,"set character_set_connection=utf8");
        mysqli_query($db,"set character_set_results=utf8");</code>

不過看到一篇文章是這麼說的：

http://zhangxugg-163-com.iteye.com/blog/1835721

按上面的描述，一條

SET NAMES UTF8

是不是就已經等於set character_set_client=utf8; set character_set_connection=utf8; set character_set_results=utf8; 大家討論下.`

<code>set NAMES utf8
show variables like "character_set_%"</code>

操作顯示是這樣的

如上回答，改變了character_set_client/character_set_connection/character_set_results三個值 是的，一條指令等於你所列的3條，主要確保編碼一致性不亂碼