Problem with mysql_num_rows in PHP

[Me01273]

Hi all, I have the follwing code which doesn't work:

function add_p_category($category) {
    
        $qLinkExists = "SELECT * FROM al_p_category WHERE category='$category'";
        $qInsertLink = "INSERT INTO al_p_category(category) 
                                        VALUES ('$category')";
                                                 
        if (mysql_num_rows($qLinkExists) > 0) {
            return "Already exists";
        }
        else {
            $result = mysql_query($qInsertLink); 
            return "Category added";
        }
    } // End: function addcategory 

It inserts into the database fine, but when I already have an entry already in the database, "if (mysql_num_rows($qLinkExists) > 0) {" should pick it up, but it just inserts it anyway. Is there anything wrong with the above code? I couldn't see anything wrong, but someone else maybe able to.

The other side of the code is this:

<?php 
if (isset($_POST['submittype'])) {
        $submittype = $_POST['submittype'];
        $id = $_POST['id'];
        $category = $_POST['category'];
        $deleteid = $_POST['deleteid'];
        $groupname = $_POST['groupname'];

$groupupdate = new permissions();
            if ($submittype == "new") {
                $perm="add_permissions";
                require("../user_control/checkperm.php");
                $id = $groupupdate->add_permission($groupname, $category);
            }
            if ($submittype == "edit") {
                $perm="edit_permissions";
                require("../user_control/checkperm.php");
                $message = $groupupdate->modify_permission($id, $category);
            }
            if ($submittype == "delete") {
                $perm="delete_permissions";
                require("../user_control/checkperm.php");
                $message = $groupupdate->delete_permission($deleteid);
            }
            if ($submittype == "newc") {
                $perm="add_perm_category";
                require("../user_control/checkperm.php");
                $message = $groupupdate->add_p_category($category);
            }
            if ($submittype == "delc") {
                $perm="delete_perm_category";
                require("../user_control/checkperm.php");
                $message = $groupupdate->delete_p_category($deleteid);
            }
    }
?>
 <div id="newc">
  <div align="center">
    <p>&nbsp;</p>
    <p>Category name:</p>
  </div>
  
    <div align="center">
        <form name="addcategory" method="Post" action="main.php?p=showpermission">
        <input type="text" name="category">
    </div>
    <div align="center">
        <input type="hidden" name="submittype" value="newc">
      <input type="Submit" value="Submit">
      <input type="button" value="Cancel" onclick="MM_showHideLayers('newc','','hide')">
            </form>
    </div>
</div>

Any help appreciated.

David

[Mark Baker]

Quoting directly from the PHP manual:

Retrieves the number of rows from a result set. This command is only valid for statements like SELECT or SHOW that return an actual result set. To retrieve the number of rows affected by a INSERT, UPDATE, REPLACE or DELETE query, use mysql_affected_rows().

[r937]

instead of doing a SELECT followed by an INSERT, why not just do a single REPLACE

[Me01273]

Its ok I figured it out.

[UFTimmy]

Its ok I figured it out.

This type of post is not helpful. The beauty of a forum is someone else can learn from your mistakes. If you don't provide the solution when you figure it out, you're wasting everyone's time.

The problem came because you fed mysql_num_rows() a string (SQL) instead of the result of the query run through mysql_query()