db connect file is another file and query is in another file. how can use mysqli_query() in it

Question

i have using mysqli_ and i want to use mysqli_query(). it need two parameters and connection is in another file. so how can i use that connection variable in it. in function code how can i write that mysqli_query() with two parameters.

connction db code

<?php
    $db_host = "localhost";
    $db_user = "root";
    $db_pass = "";
    $db_name = "chat";

    if($connection = mysqli_connect($db_host, $db_user, $db_pass)){
        echo ("connected to server");
        if($database = mysqli_select_db( $connection, $db_name )){
            echo "connected to database";
        }else{
            echo "dtabase error";
        }
    }else{
        echo "sever error";
    }
?>

function code

<?php
    global $connection;
    function get_msg(){
        $query = "SELECT Sender,Message from chat";

        $run = mysqli_query($query,$connection);

        $messages = array();

        while($message = mysqli_fetch_assoc($run)){
            $messages[] = array('sender'=>$message['Sender'],'message'=>$message['Message']);
        }

        return $messages;
    }

    function send_msg($sender,$message){
        if(!empty($sender) && !empty($message)){
            $sender = mysqli_real_escape_string($sender);
            $message = mysqli_real_escape_string($message);

            $query = "INSERT INTO chat VALUES({$sender},{$message})";

            if(mysqli_query($query)){
                return true;
            }else{
                return false;
            }
        }else{
            return false;
        }
    }

?>

Did you look at the manual? You have the same issue with the escaping. — chris85, Dec 02 '17 at 15:26
Can you update the question showing your usage as the manual displays? — chris85, Dec 02 '17 at 16:45
`mysqli_query($query,$connection)` is inverted. `global $connection;` needs to be inside the function. `mysqli_real_escape_string(` also needs the connection object. Enable error reporting and it will tell you all of this. — chris85, Dec 02 '17 at 17:14
now it's fine thank you @chris85. how can i enable error reporting. i'm new to this. — supun rajasinghe, Dec 02 '17 at 18:43
You need to a) check for PHP errors, https://stackoverflow.com/questions/1053424/how-do-i-get-php-errors-to-display and b) check for mysqli errors https://stackoverflow.com/questions/22662488/how-to-get-mysqli-error-in-different-environments — chris85, Dec 02 '17 at 18:47

Karl Wilbur · Accepted Answer · 2017-12-12T16:16:57.817

1

You need to pull those variables into your function. This can be done using the global keyword.

function send_msg($sender,$message){
    global $connection;

    if(!empty($sender) && !empty($message)){
        $sender = mysqli_real_escape_string($connection, $sender);
        $message = mysqli_real_escape_string($connection, $message);

        $query = "INSERT INTO chat VALUES({$sender},{$message})";

        if(mysqli_query($connection, $query)){
            return true;
        }else{
            return false;
        }
    }else{
        return false;
    }
}

NOTE: there are potential issues when using global and it is generally discouraged. See chris85's comment below.

edited Dec 12 '17 at 16:16

answered Dec 02 '17 at 15:26

Karl Wilbur

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1

To me the question is unclear if it is scope related or just a lack of reading the manual. Using the `global` may resolve the issue, but potential issues it could bring should be noted, https://stackoverflow.com/questions/12445972/stop-using-global-in-php. – chris85 Dec 02 '17 at 15:35
this is not wok. – supun rajasinghe Dec 02 '17 at 16:36

db connect file is another file and query is in another file. how can use mysqli_query() in it

1 Answers1