更新查询在我的代码中不起作用

The update query is not working. This query didn't work.

I tried to print the variable and all variable contain a value

How can i solve this?

Form code:

echo"<td data-title='Status'>";
if ($percent == 0) {
    echo"<form class='form-inline' role='form' action='";
    ?><?php $_PHP_SELF ?><?php

    echo"' method='post' accept-charset='UTF-8'> 
    <select id='' name='status' class='form-control input-md'>
    <option valur='.$status.'>$status</option> 
    <option value='Pending'>Pending</option>
    <option value='Cancel'>Cancel</option>
    </select>";
    echo"</td>";
    echo"<input type='hidden' name='txt_id' value='.$id.'>";
    echo"<td>";
    echo"<input type='submit' name='update' class='btn btn-default' value='Update' />";
} 
else if ($percent >= 1 && $percent < 100) {
    echo"Running";
} 
else if ($percent == 100) {
    echo"Done";
}
echo"</td>";
echo"</form>";

Update code:

if (isset($_POST['update'])) {
    $status = $_POST['status'];
    $ids = $_POST['txt_id'];
    $sql = mysqli_query($conn, "UPDATE tbl_project SET db_status='$status' WHERE db_id='$ids'")or die(mysqli_error($conn));
}

1) First of all try to remove this value='.$id.' it should be

echo"<input type='hidden' name='txt_id' value='$id'>"

beacuse it if your $id = 1; then value = '.$id.' is equal to value = '.1.';

Same thing for first option value

<option valur='.$status.'>$status</option> // this is wrong

use this

<option value='$status'>$status</option> 

2) Second try to echo your query always before running so echo your query

 if(isset($_POST['update'])){
       $status=$_POST['status'];
       $ids=$_POST['txt_id'];
     // echo "UPDATE tbl_project SET db_status='$status' WHERE db_id='$ids'";die; just to  debug

        $sql=mysqli_query($conn,"UPDATE tbl_project SET db_status='$status' WHERE db_id='$ids'") or die(mysqli_error($conn));
    }