PHP中的SQL Anywhere无法获取结果

Question

I am using SQL Anywhere in php, i use something like this:

sasql_connect ("Uid=".$uid.";Pwd=".$password.";ServerName=".$servername.";CommLinks=tcpip(host‌​=".$ip.";port=".$port.")");
$result = sasql_query("SELECT * FROM cars");

When i use:

while($row = sasql_fetch_array($result)) {
}

I get:

Warning: sasql_fetch_array(): 27 is not a valid SQLAnywhere result resource in ...

When i use:

echo get_resource_type($result);

I get 'SQLAnywhere result'

Also other functions like sasql_num_rows() don't work, what could be a reason this doesn't work? It looks like the resource is not recognized. I am 100% sure there is no error in the SQL query.