如何显示我上传到服务器中文件夹的图像？ 我使用的是php和mysql，在数据库中只保存了图片的名称

Hi As you said that you have already uploaded your image and now want to show same. In this case you should use tag with src being the path/to/imagefolder/name of image stored in db

like you have fetched your data for a perticular user

 <table  border="1">
    $sql="SELECT * FROM tbl_name";
     $result = mysql_query($sql);
     while($row=mysql_fetch_array($result))
     {
      ?>
            <tr>
            <td><?php echo $row['name'] ?></td>
            <td><?php echo $row['password'] ?></td>
            <td><?php echo $row['username'] ?></td>
            <td><img src="logo/<?php echo $row['file_name']?>"></td>
            </tr>
            <?php
     }
     ?>
    </table>

try jquery

function readURL(input) {
        if (input.files && input.files[0]) {
            var reader = new FileReader();

            reader.onload = function (e) {
                $('#image_upload_preview').attr('src', e.target.result);
            }

            reader.readAsDataURL(input.files[0]);
        }
    }

    $("#inputFile").change(function () {
        readURL(this);
    });

https://jsfiddle.net/dave17/m2oum2su/

i hope it will be helpful

include ("conexion.php");

$showimg = "SELECT rutaimg FROM usuarios WHERE user_name='$_SESSION[username]'";

$result3= mysqli_query($connection, $showimg);

$file_path = "localhost/phplogin/";

if (mysqli_num_rows($result3)>0) {

while ($row = mysqli_fetch_array($result3))

{

$src= $row['rutaimg']; 

}

}

?>

<img src="<?php echo $src; ?>">