警告：mysqli_fetch_assoc（）期望参数1为mysqli_result，boolean [duplicate]

Question

This question already has an answer here:

• mysql_fetch_array()/mysql_fetch_assoc()/mysql_fetch_row()/mysql_num_rows etc… expects parameter 1 to be resource or result 32 answers

I have warning in my code about mysql_fetch_assoc() but I think code is fine

    <?php
        $con = mysqli_connect("localhost","root","","profiles");
        $q = mysqli_query($con,"SELECT * FROM users");
        while($row = mysqli_fetch_assoc($q)){
            echo $row['username'];
            if($row['image'] == ""){
                echo "<img width='100' height='100' src='pictures/default.jpg' alt='Default Profile Pic'>";
            } else {
                echo "<img width='100' height='100' src='pictures/".$row['image']."' alt='Profile Pic'>";
            }
            echo "<br>";
        }
    ?>

</div>

Answer 1

It means your query failed. The smart move here would be to check your query if it returns false, like so:

if(!$q){
  die("Error in query:". mysqli_error($con));
}