What potential issues can arise when performing calculations with MySQL data in PHP?

One potential issue that can arise when performing calculations with MySQL data in PHP is data type mismatch. If the data types of the values retrieved from MySQL are not compatible with the calculations being performed in PHP, it can lead to unexpected results or errors. To solve this issue, you can explicitly cast the values to the desired data type before performing calculations.

// Retrieve data from MySQL
$query = "SELECT value FROM table WHERE id = 1";
$result = mysqli_query($connection, $query);
$row = mysqli_fetch_assoc($result);

// Cast the retrieved value to integer before performing calculations
$value = (int)$row['value'];

// Perform calculations
$calculationResult = $value * 2;

echo $calculationResult;