PHP，从数据库中获取数据

Question

我想用PHP从数据库中检索数据，并在网站上显示它。

此代码不能正常工作。我想在我的数据库中显示雪佛兰的所有汽车。

<?php
$db = mysqli_connect("localhost","myusername",
"mypassword","database");

if (mysqli_connect_errno()) { 
    echo("Could not connect" .
      mysqli_connect_error($db) . "</p>");
    exit(" ");
}

$result = mysqli_query($query);

if(!$result){
  echo "<p> Could not retrieve at this time, please come back soon</p>" .   
    mysqli_error($dv);
}

$data = mysql_query("SELECT * FROM cars where carType = 'Chevy' AND active = 1")
  or die(mysql_error());

echo"<table border cellpadding=3>";
while($row= mysql_fetch_array( $data ))
{
  echo"<tr>";
  echo"<th>Name:</th> <td>".$row['name'] . "</td> ";
  echo"<th>ImagePath:</th> <td>".$row['imagePath'] . " </td></tr>";
  echo"<th>Description:</th> <td>".$row['description'] . "</td> ";
  echo"<th>Price:</th> <td>".$row['Price'] . " </td></tr>";
}
echo"</table>";
?>

如何使用PHP从数据库中获取数据？

Answer 1

你没有查询数据库，所以它不会给你结果

这就是它的工作原理

1)通过mysql_connect()连接数据库

mysql_connect("localhost", "username", "password") or die(mysql_error()); 

2)然后选择数据库，如mysql_select_db()

mysql_select_db("Database_Name") or die(mysql_error()); 

3)需要使用mysql_query()

喜欢

 $query = "SELECT * FROM cars where carType = 'chevy' AND active = 1";
 $result =mysql_query($query); //you can also use here or die(mysql_error()); 

查看是否存在错误

4)和mysql_fetch_array()

  if($result){
         while($row= mysql_fetch_array( $result )) {
             //result
        }
      }

所以试一试

$data = mysql_query("SELECT * FROM cars where carType = 'chevy' AND active = 1")  or die(mysql_error()); 
 echo"<table border cellpadding=3>"; 
 while($row= mysql_fetch_array( $data )) 
 { 
    echo"<tr>"; 
    echo"<th>Name:</th> <td>".$row['name'] . "</td> "; 
    echo"<th>ImagePath:</th> <td>".$row['imagePath'] . " </td></tr>"; 
    echo"<th>Description:</th> <td>".$row['description'] . "</td> "; 
    echo"<th>Price:</th> <td>".$row['Price'] . " </td></tr>"; 
 } 
 echo"</table>"; 
 ?> 

​

备注：

不推荐使用Mysql_*函数，因此请改用PDO或MySQLi。我建议使用PDO，它更容易阅读，你可以在这里学习，也可以查看Pdo for beginners ( why ? and how ?)。

​

Answer 2

<?php 
 // Connects to your Database 
 mysql_connect("hostname", "username", "password") or die(mysql_error()); 
 mysql_select_db("Database_Name") or die(mysql_error()); 
 $data = mysql_query("SELECT * FROM cars where cars.carType = 'chevy' AND cars.active = 1") 
 or die(mysql_error()); 
 Print "<table border cellpadding=3>"; 
 while($row= mysql_fetch_array( $data )) 
 { 
 Print "<tr>"; 
 Print "<th>Name:</th> <td>".$row['name'] . "</td> "; 
 Print "<th>ImagePath:</th> <td>".$row['imagePath'] . " </td></tr>"; 
 Print "<th>Description:</th> <td>".$row['description'] . "</td> "; 
 Print "<th>Price:</th> <td>".$row['Price'] . " </td></tr>"; 
 } 
 Print "</table>"; 
 ?>