How to retrieve data from database using PHP functions?

In PHP, you can use the mysqli_query() function to retrieve database data, and use the mysqli_fetch_row(), mysqli_fetch_assoc() and mysqli_fetch_array() functions to extract results to get row data, and the mysqli_num_rows() function to get row data in the result set. quantity.

How to use PHP functions to retrieve data from the database

In PHP, a variety of functions are provided to operate the database and retrieve data. The following is a practical case of the commonly used function beserta:

mysqli_query() Function

Syntax:

mysqli_query(mysqli $link, string $query)

Actual case:

$link = mysqli_connect("localhost", "root", "password", "my_database");
$query = "SELECT * FROM users";
$result = mysqli_query($link, $query);

mysqli_fetch_row() function

Syntax:

mysqli_fetch_row(mysqli_result $result)

Practical case:

while ($row = mysqli_fetch_row($result)) {
  echo $row[0] . " " . $row[1] . "\n";
}

mysqli_fetch_assoc() function

Grammar:

mysqli_fetch_assoc(mysqli_result $result)

Practical case:

while ($row = mysqli_fetch_assoc($result)) {
  echo $row['name'] . " " . $row['email'] . "\n";
}

mysqli_fetch_array() function

Grammar:

mysqli_fetch_array(mysqli_result $result)

Practical case:

while ($row = mysqli_fetch_array($result)) {
  echo $row[0] . " " . $row['name'] . "\n";
}

mysqli_num_rows() function

Syntax:

mysqli_num_rows(mysqli_result $result)

Actual case:

$num_rows = mysqli_num_rows($result);
echo "The number of rows in the result set is: " . $num_rows;

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