PHP / Mysql条件语句

Question

I have a simple page/database setup where you can increment or decrement the point total for person A or person B.

I've gotten some help, throwing some things into their own function to clean things up. I'm new to php and mysql; reading over what I have I understand all the logic, I just can't figure out how to finish it off, in the sense that as it is now, any button will add a point; I need to get the Subtract point button working too.

My database is table 'user' with points and name within

Here's what I have:

<?php
function print_r_dump( $val )
{
echo '<pre>';
print_r( $val );
echo '</pre>';
}

//if ( isset( $_POST ) || isset( $_POST['Add point'] ) )
if ( isset( $_POST ) )
{

//Prints what's in post
print_r_dump( $_POST );

$str = "select * from user where name = '";
$str .= $_POST['person'];
$str .= "'";

$link = mysql_connect('mysql.xxxxx.net', 'xxxxx', 'xxxxx');
mysql_select_db('xxxxx_points', $link);
$result = mysql_query( $str , $link);

$row = mysql_fetch_assoc($result) ;
$points = $row['points'];

$str = 'update user set points = '. ($points+1) . ' where name = \''. $_POST['person'] . '\'';
$result = mysql_query( $str , $link);
}




$link = mysql_connect('mysql.xxxxx.net', 'xxxxx', 'xxxxx');
mysql_select_db('xxxxx_points', $link);

$str = "SELECT points FROM user WHERE name='Person A'" ;
$str = "SELECT * FROM user ";
$result = mysql_query( $str , $link);


$results = array();
while ( $row = mysql_fetch_assoc($result) )
{
$results[ $row['name'] ] = $row['points'];
}

?>

Person A's count: <?php echo $results['Person A']; ?>
<br>


<form method="post" action="index.php">
<input type="submit" name="submit_button" value="Add point" />
<input type="submit" name="submit_button" value="Subtract point" />
<input type="hidden" name="person" value="Person A" />
</form>

<br>

Person B's count: <?php echo $results['Person B']; ?>
<br>

<form method="post" action="index.php">
<input type="submit" name="submit_button" value="Add point" />
<input type="submit" name="submit_button" value="Subtract point" />
<input type="hidden" name="person" value="Person B" />
</form>

<?

print_r_dump( $results  );

?>

Answer 1

Looks like you don't necessarily need the first SQL query either. You can use the current value in the database and have it update itself, as long as the points field is numeric and not a string, for example. Try this for the major PHP portion of your code.

<?php
function print_r_dump( $val )
{
echo '<pre>';
print_r( $val );
echo '</pre>';
}

if ( isset( $_POST ) )
{

//Prints what's in post
print_r_dump( $_POST );

$link = mysql_connect('mysql.xxxxx.net', 'xxxxx', 'xxxxx');
mysql_select_db('xxxxx_points', $link);

$str = "";

    if ($_POST['submit_button']=='Add point')
    {
    $str = 'update user set points = points+1 where name = \''. $_POST['person'] . '\'';
    }
    else if ($_POST['submit_button']=='Subtract point')
    {
    $str = 'update user set points = points-1 where name = \''. $_POST['person'] . '\'';
    }
    if ($str)
    {
    $result = mysql_query( $str , $link);
    }
}

$str = "SELECT points FROM user WHERE name='Person A'" ;
$str = "SELECT * FROM user ";
$result = mysql_query( $str , $link);


$results = array();
while ( $row = mysql_fetch_assoc($result) )
{
$results[ $row['name'] ] = $row['points'];
}

?>