Converting type problem

PHP
1

Hello all,

I have a table that I am trying to extract a year from the rows if they exist.

e.g.
1857, the saga of new technology

I have tried to extract and do a type change but it doesn’t seem to work.


//  show oldest book
$count5 = mysql_query("select subject from $db_name.$table_name  ") or die();

$row5 = mysql_num_rows($count5);

// get current year
$curr_year = date('Y');

for($i=0;$i<$row5;$i++) {
    $temp = substr($row['subject'], 1, 6);
    $subject_year = (int)$temp;
    /*
    if ($subject_year > 1000 && $subject_year < $curr_year){
        $oldest_book[$i] = substr($row['subject'], 1, 4);
    }else{
        $oldest_book[$i] = "";
    } 
    */
}

It only displays zeroes. The subject is a utf-8 string coming out of a table array.

Can someone tell me what I’m doing wrong?

2

substring index starts at position 0 (zero) not position 1.

Change the

substr($row['subject'], 1, 6)

to

substr($row['subject'], 0, 6)
3

Hello zalucius,

Thanks for responding. It appears that you caught one of my mistakes.

Here is the corrected version.


//  get books by year to determine oldest book 
$result = mysql_query("select subject from $db_name.$table_name ") 
            or die('Query failed: ' . mysql_error()."<br /><br />");

// # of rows returned
$numofrows = mysql_num_rows($result);

// create array
$oldest_book = array();

// get current year for comparison
$curr_year = date('Y');

// extract year and compare
for($i=0;$i<$numofrows;$i++) {
$row5 = mysql_fetch_array ($result);
    $temp = substr($row5["subject"], 0, 6);
    $subject_year = (int)$temp;
    //print $i." - ".$subject_year."<br />";
    
    //if ($subject_year > 1000 && $subject_year < $curr_year)
    if ($subject_year != 0)
    {
        $oldest_book[$i] = $subject_year;
    }else{
        $oldest_book[$i] = "";
    } 
    
}
//print "<pre>";var_dump($oldest_book);print "</pre>";
4

Have you considered a change to your database, and store the year in a seperate field?

5

That would be a nice suggestion but I have simply inherited this from the people who use it. Another reason for this was because not every record includes a year.

Not a problem, thanks.