php mysql查询在phpmyadmin中工作，但在网页上不起作用

i wrote the following query

SELECT COUNT(userID) From statistics WHERE userID = ""

this query displays the number of unathunticated visit to the website.

the query works in phpmyadmin when i use double quotes however it doesnt when i use single quotes like below it just gives me the number of record stored in the table

 $queryB = "SELECT COUNT(userID) From statistics WHERE userID = ''";
 $resultB =mysql_query($queryA, $con) or die(mysql_error());
 $authB = mysql_result($resultB, "COUNT(userID)");

 echo "the number of authenticated visits were $authB<br />
";

i've no idea why it breaks, any ideas?

not sure if it will work...its just first think that came to mind: how about when u use escaped double quotes?

$queryB = "SELECT COUNT(userID) From statistics WHERE userID = \"\""

you store your query in $queryB but you use $queryA

Try this:

 $queryB = "SELECT COUNT(userID) AS total From statistics WHERE userID = ''";
 $resultB =mysql_query($queryB, $con) or die(mysql_error());
$authB = mysql_fetch_assoc($resultB);
 echo "the number of authenticated visits were ".$authB['total']."<br />
";

Does userID have a default value? If the default value is NULL, then change your query to

$queryB = "SELECT COUNT(userID) From statistics WHERE userID IS NULL"; 

you should change a little to your code

$queryB = "SELECT COUNT(userID) From statistics WHERE userID = ''";
$resultB =mysql_query($queryB, $con) or die(mysql_error());
$authB = mysql_result($resultB, 0, 0);

echo "the number of authenticated visits were $authB<br />
";