PHP从数据库提交后保留下拉值

Question

我想在提交更改后保留我的下拉值。

HTML 代码

<select id="Doctor" name="Doctor" onchange="this.form.submit();">
                    <?php
                    $Store->displayDoctors()
                    ?>
</select>

PHP 代码

public function displayDoctors(){
        $sql = "SELECT * FROM doctor";
        $result = @mysqli_query($this->conn, $sql);
        while($data = mysqli_fetch_array($result))
        {
            echo "<option value='". $data['docID'] ."'>" .$data['FirstName']." ".$data['LastName'] ."</option>";  
        }     
    }

Answer 1

我认为你可以像这样使用： HTML：

<select id="Doctor" name="Doctor" onchange="this.form.submit();">
                    <?php
                    $Store->displayDoctors($_REQUEST['Doctor'])
                    ?>
</select>

PHP：

public function displayDoctors($value=false){
        $sql = "SELECT * FROM doctor";
        $result = @mysqli_query($this->conn, $sql);
        while($data = mysqli_fetch_array($result))
        {
            $selected="";
            if($data['docID']==$value)
            {
              $selected="selected";
            }
            echo "<option value='". $data['docID'] ."' $selected>" .$data['FirstName']." ".$data['LastName'] ."</option>";  
        }     
    }