Question

i have an update function that updates a specific row in the table. The sql query works in PHPmyadmin and I am always returned true on the function. However, the database is not updated. I looked over the code and nothing appears wrong. What could be the problem. primary_id is the primary id of the table and the only other column is fund_max.

function change_fund_max ($mysqli, $project_id, $fund_max) {

if ($stmt = $mysqli->prepare("UPDATE `project_fund_max` SET `fund_max` = ? WHERE 
    `project_id` = ?")){
    $stmt->bind_param('ii', $project_id, $fund_max);
    $return = $stmt->execute();
    $stmt->close();
    return $return;
} else {return false;}      

}

Here is the use of the function.

$fund_max = 11.55;
$project_id = 1;
$row43 =  change_fund_max ($mysqli, $project_id, $fund_max);
var_dump($row43);

Answer 1

Execute will only return false on a failure… like you messed up the SQL or something. What you really want to know is did the command actually update on the rows… check mysqli_stmt_affected_rows to see if more than zero rows where changed.

Also your project_id and fund_max parameters are the wrong way around in your bind 😉

Result:

function change_fund_max ($mysqli, $project_id, $fund_max) {
  if ($stmt = $mysqli->prepare("UPDATE `project_fund_max` SET `fund_max`=? WHERE 
     `project_id` = ?")){
     $stmt->bind_param('di', $fund_max, $project_id);
     if (!$stmt->execute()) return false;
     $count=$stmt->affected_rows;
     $stmt->close();
     return ($count>0);
  } else {
     return false;
  }
}

Update: For sneaky “fund_max is a decimal” comment… if fund_max is a decimal you need to bind to a double otherwise you’re loosing anything right of the decimal place during the bind_param command (my code updated)