mysql_fetch_array() expects parameter 1 to be resource

[davy_yg]

Warning: mysql_fetch_array() expects parameter 1 to be resource, boolean given in C:\xampp\htdocs\administrator\admin\schedule.php on line 187

admin/schedule.php

//LOAD CLASS LIST

                $sqlstr = "SELECT * FROM class_list 
                INNER JOIN `group` 
                ON class_list.group_id = `group`.group_id
                INNER JOIN teacher
                ON class_list.teach_id = teacher.teach_id
                INNER JOIN class
                ON class_list.class_id = class.class_id
                WHERE datetime > '".date('Y-m-d H:i:s')."' ORDER BY class_list_id";

                //Create a PS_Pagination object
                $pager = new PS_Pagination($conn,$sqlstr,5,10);

                //The paginate() function returns a mysql result set 
                $result = $pager->paginate();               

                ?>
                <table id="admintable" border="1" cellpadding="2" cellspacing="0" style="width: 900px;">
                    <tr>
                        <th>Next Class List</th><th>Attendance List</th><th>Teacher</th><th>Material</th><th>Short Intro</th><th>datetime</th><th>Post</th>
                    </tr>
                    <?php
                    $i=0;
                    while ($data = mysql_fetch_array($result)){

--------------
Line 187: while ($data = mysql_fetch_array($result)){

How to fix the error?

[pritaeas]

There is an error in your query. Check for errors to see what error MySQL returns first.

[davy_yg]

I think the query is correct only if I leave the input schedule empty and trying to show the empty thing by printing empty table then nothing shows up, only one line of error.

The error disappears only if I add the input table, then the error disappears.

I am trying to make the table without any error apepars evenif I delete all the fields.

[pritaeas]

Just check what error is returned. Then you'll know what to fix. Trial and error usually takes a lot longer.

[davy_yg]

Well, this is the only error that appears:

Warning: mysql_fetch_array() expects parameter 1 to be resource, boolean given in C:\xampp\htdocs\administrator\admin\schedule.php on line 187

--------------------------

Line 187: while ($data = mysql_fetch_array($result)){

[pritaeas]

Use mysql_error()

[davy_yg]

The sql error I thought suppose to appears through this object oriented file (since I am using OOP Paging)

ps_pagination.php

<?php
/**
 * PHPSense Pagination Class
 *
 * PHP tutorials and scripts
 *
 * @package     PHPSense
 * @author      Jatinder Singh Thind
 * @copyright   Copyright (c) 2006, Jatinder Singh Thind
 * @link        http://www.phpsense.com
 */

// ------------------------------------------------------------------------


class PS_Pagination {
    var $php_self;
    var $rows_per_page = 10; //Number of records to display per page
    var $total_rows = 0; //Total number of rows returned by the query
    var $links_per_page = 5; //Number of links to display per page
    var $append = ""; //Paremeters to append to pagination links
    var $sql = "";
    var $debug = false;
    var $conn = false;
    var $page = 1;
    var $max_pages = 0;
    var $offset = 0;

    /**
     * Constructor
     *
     * @param resource $connection Mysql connection link
     * @param string $sql SQL query to paginate. Example : SELECT * FROM users
     * @param integer $rows_per_page Number of records to display per page. Defaults to 10
     * @param integer $links_per_page Number of links to display per page. Defaults to 5
     * @param string $append Parameters to be appended to pagination links 
     */

    function PS_Pagination($connection, $sql, $rows_per_page = 10, $links_per_page = 5, $append = "") {
        $this->conn = $connection;
        $this->sql = $sql;
        $this->rows_per_page = (int)$rows_per_page;
        if (intval($links_per_page ) > 0) {
            $this->links_per_page = (int)$links_per_page;
        } else {
            $this->links_per_page = 5;
        }
        $this->append = $append;
        $this->php_self = htmlspecialchars($_SERVER['PHP_SELF'] );
        if (isset($_GET['page'] )) {
            $this->page = intval($_GET['page'] );
        }
    }

    /**
     * Executes the SQL query and initializes internal variables
     *
     * @access public
     * @return resource
     */
    function paginate() {
        //Check for valid mysql connection
        if (! $this->conn || ! is_resource($this->conn )) {
            if ($this->debug)
                echo "MySQL connection missing<br />";
            return false;
        }

        //Find total number of rows
        $all_rs = @mysql_query($this->sql );
        if (! $all_rs) {
            if ($this->debug)
                echo "SQL query failed. Check your query.<br /><br />Error Returned: " . mysql_error();
            return false;
        }
        $this->total_rows = mysql_num_rows($all_rs );
        @mysql_close($all_rs );

        //Return FALSE if no rows found
        if ($this->total_rows == 0) {
            if ($this->debug)
                echo "Query returned zero rows.";
            return FALSE;
        }

        //Max number of pages
        $this->max_pages = ceil($this->total_rows / $this->rows_per_page );
        if ($this->links_per_page > $this->max_pages) {
            $this->links_per_page = $this->max_pages;
        }

        //Check the page value just in case someone is trying to input an aribitrary value
        if ($this->page > $this->max_pages || $this->page <= 0) {
            $this->page = 1;
        }

        //Calculate Offset
        $this->offset = $this->rows_per_page * ($this->page - 1);

        //Fetch the required result set
        $rs = @mysql_query($this->sql . " LIMIT {$this->offset}, {$this->rows_per_page}" );
        if (! $rs) {
            if ($this->debug)
                echo "Pagination query failed. Check your query.<br /><br />Error Returned: " . mysql_error();
            return false;
        }
        return $rs;
    }

    /**
     * Display the link to the first page
     *
     * @access public
     * @param string $tag Text string to be displayed as the link. Defaults to 'First'
     * @return string
     */
    function renderFirst($tag = 'First') {
        if ($this->total_rows == 0)
            return FALSE;

        if ($this->page == 1) {
            return "$tag ";
        } else {
            return '<a href="' . $this->php_self . '?page=1&' . $this->append . '">' . $tag . '</a> ';
        }
    }

    /**
     * Display the link to the last page
     *
     * @access public
     * @param string $tag Text string to be displayed as the link. Defaults to 'Last'
     * @return string
     */
    function renderLast($tag = 'Last') {
        if ($this->total_rows == 0)
            return FALSE;

        if ($this->page == $this->max_pages) {
            return $tag;
        } else {
            return ' <a href="' . $this->php_self . '?page=' . $this->max_pages . '&' . $this->append . '">' . $tag . '</a>';
        }
    }

    /**
     * Display the next link
     *
     * @access public
     * @param string $tag Text string to be displayed as the link. Defaults to '>>'
     * @return string
     */
    function renderNext($tag = '&gt;&gt;') {
        if ($this->total_rows == 0)
            return FALSE;

        if ($this->page < $this->max_pages) {
            return '<a href="' . $this->php_self . '?page=' . ($this->page + 1) . '&' . $this->append . '">' . $tag . '</a>';
        } else {
            return $tag;
        }
    }

    /**
     * Display the previous link
     *
     * @access public
     * @param string $tag Text string to be displayed as the link. Defaults to '<<'
     * @return string
     */
    function renderPrev($tag = '&lt;&lt;') {
        if ($this->total_rows == 0)
            return FALSE;

        if ($this->page > 1) {
            return ' <a href="' . $this->php_self . '?page=' . ($this->page - 1) . '&' . $this->append . '">' . $tag . '</a>';
        } else {
            return " $tag";
        }
    }

    /**
     * Display the page links
     *
     * @access public
     * @return string
     */
    function renderNav($prefix = '<span class="page_link">', $suffix = '</span>') {
        if ($this->total_rows == 0)
            return FALSE;

        $batch = ceil($this->page / $this->links_per_page );
        $end = $batch * $this->links_per_page;
        if ($end == $this->page) {
            //$end = $end + $this->links_per_page - 1;
        //$end = $end + ceil($this->links_per_page/2);
        }
        if ($end > $this->max_pages) {
            $end = $this->max_pages;
        }
        $start = $end - $this->links_per_page + 1;
        $links = '';

        for($i = $start; $i <= $end; $i ++) {
            if ($i == $this->page) {
                $links .= $prefix . " $i " . $suffix;
            } else {
                $links .= ' ' . $prefix . '<a href="' . $this->php_self . '?page=' . $i . '&' . $this->append . '">' . $i . '</a>' . $suffix . ' ';
            }
        }

        return $links;
    }

    /**
     * Display full pagination navigation
     *
     * @access public
     * @return string
     */
    function renderFullNav() {
        return $this->renderFirst() . '&nbsp;' . $this->renderPrev() . '&nbsp;' . $this->renderNav() . '&nbsp;' . $this->renderNext() . '&nbsp;' . $this->renderLast();
    }

    /**
     * Set debug mode
     *
     * @access public
     * @param bool $debug Set to TRUE to enable debug messages
     * @return void
     */
    function setDebug($debug) {
        $this->debug = $debug;
    }
}
?>

[pritaeas]

The paginate method returns false if there are no records, yet you do not check if it does.

if ($pager->paginate())
{
    while ($data = mysql_fetch_array($result)) { /**/ }
}
else
{
    // no records or error.
}

[iamthwee]

I thought you were using/trying to use codeigniter? What happened?

[diafol]

I thought you were using/trying to use codeigniter? What happened?

He saw the light heh heh. Sorry, carry on...

[davy_yg]

@pritaes:

I still do not know where to insert the code that you recommends:

The paginate method returns false if there are no records, yet you do not check if it does.

    if ($pager->paginate())
    {
    while ($data = mysql_fetch_array($result)) { /**/ }
    }
    else
    {
    // no records or error.
    }

I did not actually program this myself. I find ready-to-use-script on the internet. It actually works, it just shows error if there the records are empty.

[pritaeas]

Line 16 of your OP snippet...