Mysqli_result trong PHP

❮ PHP MySQLi Reference

Example - Object Oriented style

Perform query against a database:

$mysqli = new mysqli("localhost","my_user","my_password","my_db");

// Check connection
if ($mysqli -> connect_errno) {
  echo "Failed to connect to MySQL: " . $mysqli -> connect_error;
  exit();
}

// Perform query
if ($result = $mysqli -> query("SELECT * FROM Persons")) {
  echo "Returned rows are: " . $result -> num_rows;
  // Free result set
  $result -> free_result();
}

$mysqli -> close();
?>

Look at example of procedural style at the bottom.

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Definition and Usage

The query() / mysqli_query() function performs a query against a database.

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Syntax

Object oriented style:

$mysqli -> query(query, resultmode)

Procedural style:

mysqli_query(connection, query, resultmode)

Parameter Values

ParameterDescriptionconnectionRequired. Specifies the MySQL connection to usequeryRequired. Specifies the SQL query stringresultmode

Optional. A constant. Can be one of the following:

• MYSQLI_USE_RESULT (Use this to retrieve large amount of data)
• MYSQLI_STORE_RESULT (This is default)

Technical Details

Return Value:For successful SELECT, SHOW, DESCRIBE, or EXPLAIN queries it will return a mysqli_result object. For other successful queries it will return TRUE. FALSE on failurePHP Version:5+PHP Changelog:PHP 5.3.0 added the ability for async queries

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Example - Procedural style

Perform query against a database:

$con = mysqli_connect("localhost","my_user","my_password","my_db");

if (mysqli_connect_errno()) {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  exit();
}

// Perform query
if ($result = mysqli_query($con, "SELECT * FROM Persons")) {
  echo "Returned rows are: " . mysqli_num_rows($result);
  // Free result set
  mysqli_free_result($result);
}

mysqli_close($con);
?>

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❮ PHP MySQLi Reference

For those of you trying to bind rows into array,
$stmt = $db->prepare('SELECT id, name, mail, phone, FROM contacts');
$stmt->execute();
$stmt->store_result();
$stmt->bind_result($arr['id'], $arr['name'], $arr['mail'], $arr['phone']);
while ($stmt->fetch()) {
    $outArr[] = $arr;
}
$stmt->close();
return $outArr;
?>
this will give you all the rows you asked for except that they would all be the same as the first one because of some gremlins in the background code (i've heard that PHP is trying to save memory here).

But this one works:
$stmt = $db->prepare('SELECT id, name, mail, phone, FROM contacts');
$stmt->execute();
$stmt->store_result();
$stmt->bind_result($a,$b,$c,$d);
while ($stmt->fetch()) {
    $outArr[] = ['id' => $a, 'name' => $b, 'mail' => $c, 'phone' => $d];
}
$stmt->close();
return $outArr;
?>
Just don't use arrays to bind results :)

Please OH PLEASE.
I have been trying to get a result set from this function, and I had 0 luck completely, for nearly 3 hours!

If you ARE using mysqli_stmt_get_results() to get a result set, in conjuction with mysqli_stmt_store_results in order to retrieve the number of rows returned, you are going to have some major trouble!

PHP Documentation states that to retrieve the number of rows returned by a prepared select sql statement, one should call the following statements respectively:

mysqli_stmt_execute($stmt);
mysqli_stmt_store_result($stmt);
$num_rows = mysqli_stmt_num_rows($stmt);

THIS IS A MAJOR DEATH TRAP, IF YOU ARE USING mysqli_stmt_get_result() in conjunction!!!! Results of doing so vary depending which statements you call first, but in the end, you will NOT get the desired result.

In conclusion, please, PLEASE, NEVER use mysqli_stmt_store_result(), then mysqli_ AND mysqli_stmt_get_result() at the the same time. This is a MAJOR death trap.

SOLUTION:
If you are trying to get a result set, and you need the number of rows returned at the same time, use the following statements respectively instead:

$result_set = mysqli_stmt_get_results($stmt);
$num_rows = mysqli_num_rows($result_set);

Reflecting on my actions, this solution may seem fairly obvious. However, to someone new using PHP (like me) or someone who is not fully comfortable with prepared statements, it's very easy to get lost by using Google and learn on your own.

Summary:
NEVER use mysqli_stmt_store_result($stmt) & mysqli_stmt_num_rows($stmt) in conjunction with mysqli_stmt_get_result($stmt). You will regret it!! I have been stuck on this for hours, and Google offered me no answer!