PHP and Mysqli getting value of a count(distinct()) query

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后悔当初
后悔当初 2021-01-26 22:33

I have a db table in mysql called gsm, with 2 columns, LAC and NAME.

So I am trying to count how many different LAC are stored in the DB and retrieve a php value to furt

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  • 2021-01-26 22:53

    you can check with the below code , however its not tested from my end but i m sure that it would work.

     # Init the MySQL Connection
        if (!( $db = mysql_connect('localhost', 'root', '') ))
            die ('Failed to connect to MySQL Database Server - #'.mysql_errno ().': '.mysql_error ());
        if (!mysql_select_db('ram'))
            die ('Connected to Server, but Failed to Connect to Database - #'.mysql_errno ().': '.mysql_error ());
        # Prepare the SELECT Query
        $sql = "select count(distinct lac) as LAC from gsm ";
        if (!( $selectRes = mysql_query($sql) )) {
            echo 'Retrieval of data from Database Failed - #' . mysql_errno() . ': ' . mysql_error();
        } else if (mysql_num_rows($selectRes) == 0) {
    
            echo 'No Any Record Returned';
        } else {
            while ($row = mysql_fetch_assoc($selectRes)) {
                echo $row['LAC'];
            }
        }
    
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  • 2021-01-26 23:02

    In order to do this in mysqli, you need

    $count = $DB->query("SELECT COUNT( DISTINCT(LAC)) FROM gsm");
    $row = $count->fetch_row();
    echo 'LAC appears '. $row[0] . ' times in total.';
    

    So now you can use $row[0] for whatever else you want in php. It is the number of unique values of LAC in your database.

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  • 2021-01-26 23:18
    //conection:
    $link = mysqli_connect("www.mywebsite.com","user","password","dataname") or die("Error " . mysqli_error($link));
    
    //consultation:
    $query = "SELECT COUNT(DISTINCT alias) as visitors FROM Visits where time BETWEEN timestamp(DATE_SUB(NOW(), INTERVAL 1 HOUR)) AND timestamp(NOW())";
    
    //execute the query.
    $result = $link->query($query) or die("Error in the consult.." . mysqli_error($link));
    $row = mysqli_fetch_array($result);
    
    //display information:
    // The text to draw
    $text = $row['visitors'];
    
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