有没有办法在 MySQLi 中获取多行

Question

I am currently working on a project where I am required to make a list of entries from a SQL table where the id in the column is the same.

Here is the table:

+------+------+
|name  |id    |
+------+------+
|Ex1   |1     |
+------+------+
|Ex2   |1     |
+------+------+
|Ex3   |2     |
+------+------+

I have tried the code below:

$id = '1';
$query2 = "SELECT * FROM entries WHERE id = '$id'";
$data2=mysqli_query($link,$query2);
$row2=mysqli_fetch_array($data2);
$name = $row2["name"];

however that code only returns Ex2 and I would like it to return all the names with the id I specify in $id

Answer 1

Loop over successful results with a while loop.

while($row2=mysqli_fetch_array($data2)){
// echo $name = is valid syntax.
    echo $name = $row2["name"] . "<br>" . "\n";
// The \n used will show clean HTML in source.
}

Side note: You might have to use mysqli_fetch_assoc() instead of mysqli_fetch_array() .

Plus, use a prepared statement for this as it's safer, since you could be leaving yourself open to SQL injection.

• https://en.wikipedia.org/wiki/Prepared_statement

Answer 2

You can use a simple foreach loop to iterate over all the results fetched from the database.

Besides, you should use prepared statements with parameter binding.

The correct code would look something like this:

$id = '1';
$stmt = $link->prepare("SELECT * FROM entries WHERE id = ?");
$stmt->bind_param('s', $id);
$stmt->execute();
$result = $stmt->get_result();

foreach ($result as $row2) {
    $name = $row2["name"];
    // do something with the name
    echo $name.PHP_EOL;
}

Or if you want you can collect all results in an array.

$allNames = [];
foreach ($result as $row2) {
    $allNames[] = $row2["name"];
}