PHP报价问题[重复]

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 a text field called user and a submit button which displays a Json string with details of a user in the database with that id. I have the following code:

$UserID = mysql_real_escape_string($_POST['User']);

$UserCoords_Query  = "Select Accuracy, Longitude, Latitude, Timestamp 
                      FROM UserDetails
                      WHERE UserId =".$UserID;

$UserCoords_result = mysql_query($UserCoords_Query);

if (mysql_num_rows($UserCoords_result) == 0) {
    echo "There are no users with an id of ". $UserID;
}

But I am getting an error of:

Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in /home/roseanne/public_html/display_Coords.php on line 29.

I had recently switched the type of userID in my database from int to text. It worked as an int but not since the change. Can anyone see the quotes problem?

</div>

Answer 1

Timestamp is reserved word in mysql, use ` around it

$UserCoords_Query  = "Select `Accuracy`, `Longitude`, `Latitude`, `Timestamp`
                  FROM UserDetails
                  WHERE UserId = '".$UserID."'";