在PHP中获取MySQL列的总和

Question

我在表格中有一列我想加起来并返回总和.我有一个循环,但它不起作用.

while ($row = mysql_fetch_assoc($result)){
    $sum += $row['Value'];
}

echo $sum;

Answer 1

您可以在MySQL查询中完全处理它:

SELECT SUM(column_name) FROM table_name;

在PHP代码中,试试这个:

$result = mysql_query('SELECT SUM(value) AS value_sum FROM codes'); 
$row = mysql_fetch_assoc($result); 
$sum = $row['value_sum'];

使用PDO(mysql_query不推荐使用)

$stmt = $handler->prepare("SELECT SUM(value) AS value_sum FROM codes");
$stmt->execute();

$row = $stmt->fetchAll(PDO::FETCH_OBJ);
$sum = $row->value_sum;

Answer 2

$query = "SELECT * FROM tableName";
$query_run = mysql_query($query);

$qty= 0;
while ($num = mysql_fetch_assoc ($query_run)) {
    $qty += $num['ColumnName'];
}
echo $qty;

Answer 3

尝试这个：

$sql = mysql_query("SELECT SUM(Value) as total FROM Codes");
$row = mysql_fetch_array($sql);
$sum = $row['total'];