問題描述
讓對 PDO 的引用等于 PDO 對象而不是 PDO 本身--
我看到 這里 有 PDO->query() 和 PDO->exec().在鏈接的頁面中，PDO->query(); 似乎僅用于 SELECT 語句，而 PDO->exec() 用于 UPDATE,INSERT,DELETE 語句.現在，我是 PDO 的新手，所以我不確定在使用它方面發生了什么相當，所以我希望解釋為什么要使用不同的方法，以及為什么有不同的方法.
I see here that there is both PDO->query() and PDO->exec(). In the page that was linked, it appears that PDO->query(); is used for SELECT statements ONLY, and PDO->exec() is used for UPDATE,INSERT,DELETE statements. Now, I am brand new to PDO, so I'm not sure what is going on in terms of using it quite yet, so I would appreciate an explanation on why to use the different methods, and why there are different methods.
推薦答案
盡管有任何理論上的差異，但無論如何都不應該使用這些函數 - 所以，沒有什么可擔心的.
Despite of whatever theoretical difference, none of these functions should be used anyway - so, there is nothing to concern of.
使用 PDO 的唯一原因是支持準備好的語句，但這些函數都沒有提供它.因此，不應使用它們.
The only reason of using PDO is support for prepared statements, but none of these functions offers it. So, they shouldn't be used.
改用prepare()/execute()，尤其用于UPDATE、INSERT、DELETE語句.
Use prepare()/execute() instead, especially for UPDATE,INSERT,DELETE statements.
請注意，雖然準備好的聲明被廣泛宣傳為一種安全措施，但它只是為了引起人們的注意.但他們真正的目的是正確的查詢格式.這也為您提供了安全性 - 因為格式正確的查詢也不能被注入 - 就像副作用一樣.但同樣 - 格式化是一個主要目標，因為如果格式不正確，即使是無害的數據也可能導致查詢錯誤.
Please note that although prepared statements are widely advertised as a security measure, it is only to attract people's attention. But their real purpose is proper query formatting. Which gives you security too - as properly formatted query cannot be injected as well - just as side effect. But again - formatting is a primary goal, just because even innocent data may cause a query error if not formatted properly.
請注意，execute() 僅返回 TRUE 或 FALSE 以指示操作成功.對于其他信息，例如受 UPDATE 影響的記錄數，提供了諸如 rowCount() 之類的方法.請參閱文檔.
Please note that execute() returns only TRUE or FALSE to indicate success of the operation. For other information, such as the number of records affected by an UPDATE, methods such as rowCount() are provided. See the docs.
這篇關于PDO->query() 和 PDO->exec() 之間的區別的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！