Question

I have webpage that need to be upated for example if the articles in certain tables has passed 7 days then the page will view notification window that there is some old articls need to be updated

How do I check dates across multiple tables?

$sql = "select topic.*
            ,   id.* 
        from    $table_1
            ,   $table2 
        where (date of the article) < (<date  of the article+ 7 days...>)" ;
        // the arctile has passed 7 days 
$rs     = mysql_query($sql);
$nos    = mysql_num_rows($rs);
$obj    = mysql_fetch_object($rs);
if($row = mysql_fetch_array($sql)) 
{ 
    // I want to display window that display note 
    // there is artiles need to be updated and list of those topics"
    <script language="javascript" type="text/javascript">
        function print_msg(opt,id) 
        {
            if(confirm("show old topics")) 
            {
                window.location="home.php";
            } 
            else 
            {
                return false;
            }
        }
    </script>
    //here are the topics need to be updated           
    echo obj->topic;
} 

Answer 1

I think you have to use UNION ALL to join the rows in both the tables. After joining the rows, you can perform a SELECT on the derived table output to check your date condition. Here is the SQL query. I don’t know about PHP syntax.

If you want to fetch only distinct rows among the two tables, change UNION ALL to UNION.

Query: Something along this line in MySQL.

SELECT id, topic, date
FROM
(
    SELECT id, topic, date FROM table1
    UNION ALL 
    SELECT id, topic, date  FROM table1
) T1
WHERE DATEDIFF(date, DATE(NOW())) <= 7

T1 in the above query represents an alias for the derived table output.