代码Javascript与PHP出错（不能完美运行）

I wanna make statistics with month for my website, Show result for each month of this years like this

Month 1 : 195
Month 2 : 3 
Month 3 : 45
Month 4 : 15
Month 5 : 75
Month 6 : 100

I try my own code but I have problem, the code give me just 1 one result like this

Month 6 : 100

I try other code with arrays but it's doesn't work, it doesn't show any things

My own php code :

$date1 = date('m');
$date2 = date('Y');
$n = $date1;

 for($i=1;$i<=$n;$i++) {
    $sql = "SELECT sum(count) AS value_sum FROM statistics where MONTH(st_date) = $i and YEAR(st_date) = $date2 ";
    $sql_sel = mysqli_query($conn,$sql);
    echo'   <script>
    var doughnutData = [';
    while($rows = mysqli_fetch_assoc($sql_sel)) {
        if($i == 1) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#337AB7"
            },';
        }
        else if($i == 2) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#929292"
            },';
        }
        else if($i == 3) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#8BC34A"
            },';
        }
        else if($i == 4) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#FC8213"
            },';
        }
        else if($i == 5) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#90AE00"
            },';
        }
        else if($i == 6) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#15AE00"
            },';
        }
        else if($i == 7) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#FF0080"
            },';
        }
        else if($i == 8) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#AEB404"
            },';
        }
        else if($i == 9) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#0431B4"
            },';
        }
        else if($i == 10) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#B40404"
            },';
        }
        else if($i == 11) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#F7819F"
            },';
        }
        else if($i == 12) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#81F781"
            },';
        }
echo'];
new Chart(document.getElementById("doughnut").getContext("2d")).Doughnut(doughnutData);
</script>';
    }
}

I wanna show all result, so, Any help ?

try this.

dbconfig.php

<?php
        $host = 'localhost';
        $dbname = 'dbname';
        $username = 'user';
        $password = 'pass';
    ?>

index.php

<?php
$date1 = date('m');
$date2 = date('Y');
$n = $date1;

 for($i=1;$i<=$n;$i++) {
    require_once 'dbconfig.php';
    try {
      $conn = new PDO("mysql:host=$host;dbname=$dbname", $username, $password);
      $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
      $sql = "SELECT sum(count) AS value_sum FROM statistics where MONTH(st_date) = $i and YEAR(st_date) = $date2
      ";
      $q = $conn->query($sql);
      $q->setFetchMode(PDO::FETCH_ASSOC);
    } catch (PDOException $pe) {
      die("Could not connect to the database $dbname :" . $pe->getMessage());
    }
    while ($rows = $q->fetch()) {
        if($i == 1) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#337AB7"
            },';
        }
        else if($i == 2) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#929292"
            },';
        }
        else if($i == 3) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#8BC34A"
            },';
        }
        else if($i == 4) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#FC8213"
            },';
        }
        else if($i == 5) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#90AE00"
            },';
        }
        else if($i == 6) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#15AE00"
            },';
        }
        else if($i == 7) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#FF0080"
            },';
        }
        else if($i == 8) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#AEB404"
            },';
        }
        else if($i == 9) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#0431B4"
            },';
        }
        else if($i == 10) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#B40404"
            },';
        }
        else if($i == 11) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#F7819F"
            },';
        }
        else if($i == 12) {
            echo '{
            value: '.$rows['value_sum'].',
            color:"#81F781"
            },';
        }
    }
}
?>

table

ID> unique>int>auto_increment
st_date> Date
count>int