Question

我正在计算有多少胜/负以及多少场比赛。

我有一个名为周的数据库，在那里我存储了不少列，但现在需要计算我搜索过的所有周的获胜和总损失总数，并找到this page，这显示了一个很好的例子如何使用SUM。

我的表名为周，看起来像这样

id | fs1 | fs2 | fs3 | => fs12

我每周都在插入行，例如

id | fs1 | fs2 | fs3 | => fs12
1     0     1     0        1           =2 wins
2     0     1     1        1           =3 wins

所以使用我上面链接的网站代码;这是我目前的代码，但它不起作用。

 <?
//set connection variables
$host = "localhost";
$username = "root";
$password = "";
$db_name = "pool"; //database name

//connect to mysql server
$mysqli = new mysqli($host, $username, $password, $db_name);

//check if any connection error was encountered
if(mysqli_connect_errno()) {
    echo "Error: Could not connect to database.";
    exit;
}
 $getTotalPoints = mysql_query("SELECT SUM(fs1 + fs2 + fs3 + fs4 + fs5 + fs6 + fs7 + fs8 + fs9 + fs10 + fs11 + fs12) wins FROM weeks");     
    $TotalPoints = mysql_fetch_array($getTotalPoints);
    echo $TotalPoints['wins'];
?>

此代码给出了以下错误Warning: mysql_fetch_array() expects parameter 1 to be resource, boolean given in line 6

哪个是$TotalPoints = mysql_fetch_array($getTotalPoints);

当我直接向数据库查询时，我收到以下消息

This table does not contain a unique column. Grid edit, checkbox, Edit, Copy and Delete features are not available.

Showing rows 0 - 0 ( 1 total, Query took 0.0012 sec)


wins
59

Answer 1

您已为数据库连接创建了mysqli对象，因此您必须使用至少需要2个参数的mysqli_query方法。

$getTotalPoints = mysqli_query($mysqli, 
"SELECT SUM(fs1 + fs2 + fs3 + fs4 + fs5 + fs6 + 
fs7 + fs8 + fs9 + fs10 + fs11 + fs12) wins FROM weeks");

此外，对于mysql_fetch_array()方法，您必须使用mysqli_一个

$TotalPoints = mysqli_fetch_array($getTotalPoints);

使用错误布尔值计算多列中的值

1 个答案: