PHP：从MYSQL数据库创建选择选项？

Question

I'm trying to create multiple select dropdowns from MYSQL database!

basically I need to create select dropdowns based on the given sub-categories and put every op_value related to that sub_cate_name under the created dropdown menu as options.

at the moment, my code creates the dropdowns and select options BUT it will put them in separate select dropdwons and all over the place.

For example: if we have 2 sub_cate_name as Apples and 3 op_value as Reds, Greens, Yellows it will create 2 select dropdown menus and split them op_value which is (Reds, Greens, Yellows) as select options where ever it likes!

but i need it to make sure it creates 1 select dropdown as Apples and put ever op_value related to apples under the Apples dropdown as option!

This is code seems to have mind of its own as it works sometimes and it doesn't others!

this is the entire code:

$drops ="";

$sql44 ="SELECT * FROM drop_options WHERE sub_cat_name='$currentproduct'";

$query44 = mysqli_query($db_conx, $sql44);
$productCount44 = mysqli_num_rows($query44);
if ($productCount44 > 0) 
{
    $op_name = '';
    $first = 0;

    while($row44 = mysqli_fetch_array($query44, MYSQLI_ASSOC))
    {


            $op_value = $row44["op_value"];

            if($op_name != $row44["op_name"])
            {
               if($first)
                {
                    $drops .='</select></div>';
                }

                $op_name = $row44["op_name"];

                $drops .='<div class="col-md-3 col-xs-12">
                <p class="margin-bottom-zero">'.$op_name.'</p>
                <select name="keyword[]" class="selectpicker">

                <option value="'.$op_value.'">'.$op_value.'</option>';
            }
            else
            {
                $drops .= '<option value="'.$op_value.'">'.$op_value.'</option>';
            }

            /*$first = 1;*/
            $first++;
    }
} 
else 
{
    $drops ='';
}
$drops .='</select></div>';
echo $drops;

Could someone please advise on this issue?

any help would be appreciated.

EDIT:

Okay, now i tried it this way and I can get the exact amount of the select drop downs created as it should:

if($db_conx->connect_errno > 0){
    die('Unable to connect to database [' . $db_conx->connect_error . ']');
};


// Perform queries
$sql45 = "SELECT DISTINCT op_name FROM drop_options WHERE sub_cat_name='Custom Booklets";
$result45 = $db_conx->query($sql45);

//echo '<li class="product-types">';


foreach ($result45 as $menu45)
{
    // echo "<li>".$menu["cat_name"];
echo '<div class="col-md-3 col-xs-12">
                <p class="margin-bottom-zero">'.$menu45["op_name"].'</p>
                <select name="keyword[]" class="selectpicker">';




     //echo "<ul>";
    $menu_title45 = $menu45["sub_cat_name"];

    $sql455 = "SELECT * FROM drop_options WHERE op_name='".$menu45["op_name"]."'";    

    $result455 = $db_conx->query($sq455);
    foreach ($result455 as $submenu455)
    {
        //echo "<li>".$submenu["sub_cat_name"]."</li>";

        echo '<option value="'.$submenu455["op_value"].'">'.$submenu455["op_value"].'</option>';
    }
     echo "</select>";
     echo "</div>";
}


//echo "</ul>";
$db_conx->close();

BUT i get no select options created at all Also i get this error: Warning: Invalid argument supplied for foreach() in line 18

and this is on line 18 : foreach ($result45 as $menu45){

any idea what i'm doing wrong?

Answer 1

This is how you're code should look like-

    // Perform queries
    $sql45 = "SELECT DISTINCT op_name FROM drop_options WHERE sub_cat_name='Custom Booklets'";
    $result45 = $db_conx->query($sql45);

    //echo '<li class="product-types">';


    while ($menu45 = mysqli_fetch_array($result45,MYSQLI_ASSOC))
    {
        // echo "<li>".$menu["cat_name"];
        echo '<div class="col-md-3 col-xs-12">
            <p class="margin-bottom-zero">'.$menu45["op_name"].'</p>
            <select name="keyword[]" class="selectpicker">';


        //echo "<ul>";
        $menu_title45 = $menu45["sub_cat_name"];

        $sql455 = "SELECT * FROM drop_options WHERE op_name='".$menu45["op_name"]."'";

        $result455 = $db_conx->query($sql455);
        while($submenu455 = mysqli_fetch_array($result455,MYSQLI_ASSOC))
        {
            //echo "<li>".$submenu["sub_cat_name"]."</li>";

            echo '<option value="'.$submenu455["op_value"].'">'.$submenu455["op_value"].'</option>';
        }
        echo "</select>";
        echo "</div>";
    }


    //echo "</ul>";
    $db_conx->close();

You may want to add if condition to check whether there are actually select options so you wont end up with an empty select.