Warning: mysql_fetch_assoc() expects parameter 1 to be resource?

这个报错是不是数据库的问题?求大佬解答下,谢谢!

<?php
$con = mysqli_connect( 
 'localhost', /* The host to connect to 连接MySQL地址 */   
 'root',   /* The user to connect as 连接MySQL用户名 */   
 'root', /* The password to use 连接MySQL密码 */   
 'wechat');  /* The default database to query 连接数据库名称*/  
 
$sql = "SELECT * FROM abc";

$result = mysqli_query($con, $sql);

//将数据给弄出来
if (mysqli_num_rows($result) > 0){
    
$data = array();
while ($row = mysqli_fetch_assoc($result)) {
     $data[] = $row;
}

//随机个数，默认1
$rand_times = 1;
$rand_times = count($data)<$rand_times?count($data):$rand_times;
$ress = array();
for( $i=0;$i<$rand_times;$i++ ){
    $ress[] = $data[rand(0,count($data)-1)][0]; 
    echo $ress;
}
}
?>