如何制作 PDO 类方法，用于在 arg 中使用未知数量

问题描述

目前我正在尝试创建一个 PDO 类，我将在其中使用一种方法来运行诸如 INSERT、UPDATE 或 DELETE 之类的查询.

Currently Im trying to create a PDO class where I will have a method to run a query like INSERT, UPDATE, or DELETE.

例如，这是我的 SELECT 方法

For examaple this is my method for a SELECT

 public function getPreparedQuery($sql){
    $stmt = $this->dbc->prepare($sql);
    $stmt->execute([5]);
    $arr = $stmt->fetchAll(PDO::FETCH_ASSOC);
    if(!$arr) exit('No rows');
    $stmt = null;
    return $arr;
}

我只是这样称呼它:

    $stmt = $database->getPreparedQuery($sql2);
var_export($stmt);

到目前为止，我知道 runQuery 应该像这样工作:

And so far I know that a runQuery should work something similar to this:

不使用方法插入示例:

$idRol = "6";
$nomRol = "test6";                          
$stmt = $database->dbc->prepare("insert into roles (idRol, NomRol) values (?, ?)");
$stmt->execute(array($idRol,$nomRol));
$stmt = null;

但我想把它变成一个通用的方法，我可以简单地传递sql语句，就像这样:

But I want to make it into an universal method where i simply can pass the sql sentence, something like this:

$database->runQuery($query);

但查询可能恰好是

$query = "插入角色 (idRol, NomRol) VALUES ('4','test')";

$query = "INSERT INTO roles (idRol, NomRol) VALUES ('4','test')";

或

$query = "插入电影 (movName, movLength, movArg) VALUES ('name1','15','movie about...')";

$query = "INSERT INTO movies (movName, movLength, movArg) VALUES ('name1','15','movie about...')";

那么我如何对 arg $query 进行切片，以便我可以获取所有正在使用的变量以创建一个通用的 runQuery?

So how do I slice the arg $query so I can get all the variables that are being used in order to make an universal runQuery?

因为我可以想象我的方法应该是这样的

Because I can imagine that my method should be something like this

runQuery([$var1 , $var2, $var3....(there can be more)] , [$var1value, $var2value, $var3value...(there can be more)]){

        $stmt = $database->dbc->prepare("insert into movies($var1 , $var2, $var3....(there can be more)) values (?, ? , ? (those are the values and there ca be more than 3)"); //how do i get those "?" value and amount of them, and the name of the table fields [movName, movLength, movArg can be variable depending of the sentence]?
        $stmt->execute(array($var1,$var2, $var3, ...)); //this is wrong , i dont know how to execute it
        $stmt = null;
}

推荐答案

您需要向函数中添加第二个参数.只是一个数组，所有这些变量都会在其中.根据定义，数组可以包含任意数量的元素，这正好可以解决您的问题:

You need to add a second parameter to your function. Simply an array where all those variables would go. An array by definition can have an arbitrary number of elements, which solves your problem exactly:

public function runQuery($sql, $parameters = []) {
    $stmt = $this->dbc->prepare($sql);
    $stmt->execute($parameters);
    return $stmt;
}

这个简单的函数将运行任何查询.您可以在我专门介绍 PDO 辅助函数的文章中查看使用示例:

this simple function will run ANY query. You can see the usage example in my article dedicated to PDO helper functions:

// getting the number of rows in the table
$count = $db->runQuery("SELECT count(*) FROM users")->fetchColumn();

// the user data based on email
$user = $db->runQuery("SELECT * FROM users WHERE email=?", [$email])->fetch();

// getting many rows from the table
$data = $db->runQuery("SELECT * FROM users WHERE salary > ?", [$salary])->fetchAll();

// getting the number of affected rows from DELETE/UPDATE/INSERT
$deleted = $db->runQuery("DELETE FROM users WHERE id=?", [$id])->rowCount();

// insert
$db->runQuery("INSERT INTO users VALUES (null, ?,?,?)", [$name, $email, $password]);

// named placeholders are also welcome though I find them a bit too verbose
$db->runQuery("UPDATE users SET name=:name WHERE id=:id", ['id'=>$id, 'name'=>$name]);

// using a sophisticated fetch mode, indexing the returned array by id
$indexed = $db->runQuery("SELECT id, name FROM users")->fetchAll(PDO::FETCH_KEY_PAIR);

如您所见，现在您的函数可以用于具有任意数量参数的任何查询

As you can see, now your function can be used with any query with any number of parameters

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