Increment value in MySQL update query

To increment a value in a MySQL update query using PHP, you can use the += operator. For example:

<?php

$sql = "UPDATE table_name SET column_name = column_name + 1 WHERE condition";

if ($conn->query($sql) === true) {
  // Record updated successfully
} else {
  echo "Error updating record: " . $conn->error;
}

This will update the value of column_name by adding 1 to its current value.

Alternatively, you can use the $conn->query() function to run the update query and use the mysqli_affected_rows() function to check if the query was successful:

<?php

$result = $conn->query($sql);

if ($conn->affected_rows > 0) {
  // Record updated successfully
} else {
  echo "Error updating record: " . $conn->error;
}

Remember to always sanitize any user input to prevent SQL injection attacks. You can use the mysqli_real_escape_string() function for this purpose.