需要帮助理解 mySQL PHP 项目

Question

我被要求完成一个高级 Web 应用程序学生的项目，我试图理解所有代码，但它变得非常困难。我很感激对代码行的一些帮助。我已经在评论台词以帮助我前进。您也可以评论这些行，以便我可以推进代码吗？感谢您的提前合作。这只是一个挑战，所以对任何人都没有压力，我只是寻求善意的帮助。代码是葡萄牙语，希望不会有太大区别，如果是这样，我会澄清的。

（代码已验证）

<?php

require_once("top.php"); //incluir ficheiro uma única vez

$idvoo= !empty($_GET["idvoo"]) ? $_GET["idvoo"] : null; //verifica se a variável existe ou retorna valor nulo

$query= "select a.ID, a.TotalFilas, a.LugaresPorFila_Esquerda,".
" a.LugaresPorfila_Central, a.LugaresPorFila_Direita FROM aviao as a".
" WHERE a.ID = (SELECT v.IDAviao FROM voo as v WHERE v.ID = ?)" ; //Consulta os parâmetros especificados no código da 
                                                              //respectiva tabela (aviao)
 //echo $query;
 //die;

$stmt = $mydb->prepare($query); //Prepara a consulta para a base de dados
//var_dump($mydb->error);


$stmt->bind_param("i", $idvoo); //Muda o valor do parãmetro "?" para "idvoo"

$stmt->execute();               //Executa o mysql


$result = $stmt->get_result();  //Obtem os resultados
$aviao = $result->fetch_assoc();//Cria um array associativo do resultado mysql

//var_dump($aviao);

谢谢大家的回答，他们非常快，因为他们我可以理解更多的代码。特别是我以前从未使用过的语句查询。如果你还有时间我还有更多的代码需要理解，就不用评论重复的语句，比如“$stmt”"query"等

echo "<h1>Lugares</h1>";
echo "<table border=1>";
echo "<thead><tr><th>Fila</th>"; //Construção da Tabela Lugares

$letras = array('A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I');//Criação de um array com as letras relativas a cada linha de lugares

$posicao = 0;
for ($i=0; $i < $aviao['LugaresPorFila_Esquerda']; $i++) { 
    echo "<th>".$letras[$posicao]."</th>";
    $posicao++;
}
for ($i=0; $i < $aviao['LugaresPorfila_Central']; $i++) { 
    echo "<th>".$letras[$posicao]."</th>";
    $posicao++;
}
for ($i=0; $i < $aviao['LugaresPorFila_Direita']; $i++) { 
    echo "<th>".$letras[$posicao]."</th>";
    $posicao++;
}

echo "</tr>";

//Consulta os parâmetros especificados no código da tabela bilhete
$query= "select b.ID, b.IDVoo, b.NumFila, b.LetraLugar,".
" b.Estado, v.ID as IDVoo FROM bilhete as b 
INNER JOIN voo as v ".
" ON b.IDVoo = v.ID".                                               
" WHERE ((b.IDVoo=?) OR (? is NULL)) AND (b.Estado='L') ORDER BY b.NumFila, b.LetraLugar" ;

$stmt = $mydb->prepare($query);



$stmt->bind_param("ii", $idvoo,$idvoo);

$stmt->execute();


$result = $stmt->get_result();

echo "<table border=1>";
        echo "<tr>";
        echo "<th>Bilhete Nº:</th>";
        echo "<th>Fila:</th>";
        echo "<th>Lugar:</th>";
        echo "</tr>";
while ($bilhete = $result->fetch_assoc()){


    //if ($bilhete["Estado"] == "L") {

        echo "<tr>";
        echo '<td class="form-control"><a class="btn btn-success btn-sm"     href="carrinho.php?id='.$bilhete["ID"].'">  Adicionar </a></td>';
        echo "<td>" .$bilhete["NumFila"]."</td>";
        echo "<td>" .$bilhete["LetraLugar"]."</td>";
        echo "</tr>";
//  }

}
echo "</table>";

Answer 1

<?php
require_once("top.php"); // included a file

$idvoo= !empty($_GET["idvoo"]) ? $_GET["idvoo"] : null; // Assigned the value to $idvoo
$query= "select a.ID, a.TotalFilas, a.LugaresPorFila_Esquerda,".
" a.LugaresPorfila_Central, a.LugaresPorFila_Direita FROM aviao as a".
" WHERE a.ID = (SELECT v.IDAviao FROM voo as v WHERE v.ID = ?)" ; // Constructed SQL query.
//echo $query;
//die;

$stmt = $mydb->prepare($query); // Prepared SQL statement.
//var_dump($mydb->error);
$stmt->bind_param("i", $idvoo); // Bound parameter $idvoo to the question mark in query 'WHERE v.ID = ?)'
$stmt->execute(); // Executed the SQL statement so that we get results.
$result = $stmt->get_result();  // Get results from Database
$aviao = $result->fetch_assoc(); // Fetch associative array for the result set from SQL.
//var_dump($aviao);

Answer 2

这里是进一步注释的代码。

//Require another File
require_once("top.php");

//Check if the Get Variable Exists else give it a value of null
$idvoo= !empty($_GET["idvoo"]) ? $_GET["idvoo"] : null;

//Create a Mysql Query for the database
$query= "select a.ID, a.TotalFilas, a.LugaresPorFila_Esquerda,".
" a.LugaresPorfila_Central, a.LugaresPorFila_Direita FROM aviao as a".
" WHERE a.ID = (SELECT v.IDAviao FROM voo as v WHERE v.ID = ?)" ;




//Prepare to query the database
$stmt = $mydb->prepare($query);

//Change the ? in the query to $idvoo declared earlier
$stmt->bind_param("i", $idvoo);

//Execute the MySQL
$stmt->execute();

//Fetch the results of the query
$result = $stmt->get_result(); 

//Create an associative array with the result
$aviao = $result->fetch_assoc();

//Set up a table with three columns (th being column header)
echo "<table border=1>";
        echo "<tr>";
          echo "<th>Bilhete Nº:</th>";
          echo "<th>Fila:</th>";
          echo "<th>Lugar:</th>";
        echo "</tr>";

    //While we have results from the database lets loop through them one by one
    while ($bilhete = $result->fetch_assoc())
    {


        //if ($bilhete["Estado"] == "L") {
        //Foreach result we have, create a new row and insert the values into the relevant columns. The first column will be a link that will pass the ID to another page for processing again using a $_GET variable
        echo "<tr>";
            echo '<td class="form-control"><a class="btn btn-success btn-sm"     href="carrinho.php?id='.$bilhete["ID"].'">  Adicionar </a></td>';
            echo "<td>" .$bilhete["NumFila"]."</td>";
            echo "<td>" .$bilhete["LetraLugar"]."</td>";
        echo "</tr>";
       // }

    }
  //Now we have looped through the results, close the table element. If there were no results we would simply see a table with heading and no rows of information
  echo "</table>";

很简单，您是根据 $_GET 变量的值从数据库中检索行。因此，请尝试像这样导航到您的脚本：

http://url-to-script?idvoo=1
http://url-to-script?idvoo=2

这意味着 $_GET['idvoo'] 的值在第一个示例中为 1，在第二个示例中为 2。如果你没有把 get 参数放在 URL 中，它将检查的 id 将为 null，如这一行所示：

$idvoo= !empty($_GET["idvoo"]) ? $_GET["idvoo"] : null;

Answer 3

<?php

require_once("top.php"); //The statement compels the page to be run in presence of this top.php i.e. top.php must be available in the page

$idvoo= !empty($_GET["idvoo"]) ? $_GET["idvoo"] : null; //it states that if GET variable idvoo is not empty then idvoo variable will be assign a value of the same and in opposite a null value will be assigned.

$query= "select a.ID, a.TotalFilas, a.LugaresPorFila_Esquerda,".
" a.LugaresPorfila_Central, a.LugaresPorFila_Direita FROM aviao as a".
" WHERE a.ID = (SELECT v.IDAviao FROM voo as v WHERE v.ID = ?)" ;//The above query states that select some fields from table aviao with respect to selection of v.IDAviao from another table voo 
$stmt = $mydb->prepare($query);`//preparing the query..using PDO
$stmt->bind_param("i", $idvoo);//Binding the parameter to variable name..read [this][1] 

$stmt->execute();//Executing the query
`$result = $stmt->get_result(); //Getting the result



`$aviao = $result->fetch_assoc();`//storing in associative array.
//var_dump($aviao);

需要帮助理解 mySQL PHP 项目

Need help understanding mySQL PHP project

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