php计数图像不是所有行只有图像

Question

我想计算图像的数量，但不是所有的行 这是我的功能：

function profile_count_image($user_id) {
    global $Connection;

    $sql_query = mysqli_query($Connection, "SELECT image FROM posts WHERE added_by='$user_id'"); 
    $num_rows = mysqli_num_rows($sql_query);

    return $num_rows;   
}

这就是我在数据库中所拥有的：

回声（回归）告诉我：5 ??? （正确是1但显示5）

Answer 1

试试这个

$sql_query = mysqli_query($Connection, "SELECT image FROM posts WHERE added_by='$user_id' AND image !=''");

Answer 2

在查询中添加一个谓词，用于检查图像字段是否为空：

Select image from posts where added_by='$user_id' and image is not null

Answer 3

变化：

$sql_query = mysqli_query($Connection, "SELECT image FROM posts WHERE added_by='$user_id'");

要：

$sql_query = mysqli_query($Connection, " SELECT image FROM posts WHERE added_by = '$user_id' AND image IS NOT NULL ");