如何从MYSQL数据库中检索特定ID的详细信息

Question

Getting data from the database depending on the value of the id in the URL.

$id= $_GET['id'];
$strSQL = "SELECT * FROM people WHERE id='$id'";
$rs = mysql_query($strSQL);

This is working, But it's displaying a blank page.

How can i fix this ?

Answer 1

[1]. mysql_* is deprecated.

[2]. Your code is VERY vulnerable to sql injection. Sanitize $_GET['id'] with mysql_real_escape_string($_GET['id']) ( mysqli if you update to that)

[3]. The results are returned as resources. Loop through it with:

$rs = mysql_query($strSQL);
while($r = mysql_fetch_array($rs)) { echo $r['someField']; }

Answer 2

I don't recommend using mysql_query since it is deprecated.

This extension is deprecated as of PHP 5.5.0, and will be removed in the future.

I recommend using MySQLi or PDO .

But if you insist on using the mysql_ functions you can use mysql_fetch_assoc to get the details returned in an associative array key'd on field names.

$id= $_GET['id'];
$strSQL = "SELECT * FROM people WHERE id='$id'";
$rs = mysql_query($strSQL);
if (!$rs) {
    echo 'Could not run query: ' . mysql_error(); //A bit of error checking
    exit;
}

$row = mysql_fetch_assoc($rs);

if($row){
  echo $row['field']; // An array key'd on the table's field names is returned
}

If a field in your people table is named first_name then that value would be stored in $row['first_name'] in the returned associative array.

I assume id is a unique field and at most you expect one row returned. If that is not the case use a loop with the condition while($row = mysql_fetch_assoc($rs)) to loop through all returned rows.

Answer 3

As I mentioned in my original comment:

"You need to use a loop in order to fetch the data, then echo it."

Others have given you examples and not to use your present method, here is a PDO method:

<?php
$mysql_hostname = 'xxx';
$mysql_username = 'xxx';
$mysql_password = 'xxx';
$mysql_dbname = 'xxx';

$id = $_GET['id'];

try {

$pdo= new PDO("mysql:host=$mysql_hostname;dbname=$mysql_dbname", $mysql_username, $mysql_password); 
     $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch (PDOException $e) {
     exit( $e->getMessage() );
}


try {

$stmt = $pdo->prepare('SELECT * FROM people WHERE id = :id');
$stmt->bindParam(':id', $id);
$stmt->execute();

} catch (PDOException $e) {
     echo $e->getMessage();
}

/* optional method
foreach($stmt as $row) {
      echo $row['id'] . ' ' . $row['name'] . ' ' . $row['email'];
}
*/

while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
  $id = $row['id'];
  $n = $row['name'];
  $e = $row['email'];
}

echo $id;
echo "<br>";
echo $n;
echo "<br>";
echo $e;

?>

---

Another PDO method:

<?php
$mysql_hostname = 'xxx';
$mysql_username = 'xxx';
$mysql_password = 'xxx';
$mysql_dbname = 'xxx';

$id = $_GET['id'];

// $id= 4; // my own test id number

try {

$pdo= new PDO("mysql:host=$mysql_hostname;dbname=$mysql_dbname", $mysql_username, $mysql_password); 
     $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch (PDOException $e) {
     exit( $e->getMessage() );
}

try {
     $sql = "SELECT * FROM people WHERE id='$id'";
     $results = $pdo->query($sql);

} catch (PDOException $e) {
     echo $e->getMessage();
}

/* optional method
foreach($results as $row) {
      echo $row['id'] . ' ' . $row['name'] . ' ' . $row['email'];
}
*/

while ($row = $results->fetch(PDO::FETCH_ASSOC)) {
  $id = $row['id'];
  $n = $row['name'];
  $e = $row['email'];
}

echo $id;
echo "<br>";
echo $n;
echo "<br>";
echo $e;

?>

Answer 4

You have to fetch result.

try like this:

$id= $_GET['id'];
$strSQL = "SELECT * FROM people WHERE id='$id'";
$rs = mysql_query($strSQL);
while ($row = mysql_fetch_array($rs, MYSQL_ASSOC)) {
    echo $row['id']; //$row is an array of each row of your table
}

see details

mysql_* functions are deprecated you should switch to mysqli_* or pdo

Answer 5

    $id= $_GET['id'];
    $strSQL = "SELECT * FROM people WHERE id='$id'";
    $rs = mysql_query($strSQL);
    $row = mysql_fetch_array($rs);
    $num_rows = mysql_num_rows($row);
      if($num > 0)
      {  
         foreach($row as $r) 
         {
         echo $r;          
         }
      }
      else
      {
         echo "No rows "
      }

This code will display the values . Note: mysql_query will be deprecated in later version of PHP. So better start with mysqli or PDO's in PHP.