php与mysql表中如何求递归求和汇总?

function sumShuzi(&$tree, &$updateData = array()) {

  $sum = 0

  // foreach($tree as $key => $item) {  //这句话有毒

  foreach($tree as $key => &$item) {

    if(isset($item['children'])) {

      $oldPshuzi = $tree[$key]['Pshuzi']

      $tree[$key]['Pshuzi'] = sumShuzi($item['children'], $updateData)

      if($oldPshuzi != $tree[$key]['Pshuzi']) {

        $updateData[$item['id']] = array($tree[$key]['Pshuzi'], $tree[$key]['Pname_ch'])

      }

    }

    $sum += $tree[$key]['Pshuzi']

  }

  return $sum

}

$tree = json_decode('[{"id":"1","Pid":"0","Pname_ch":"\u6e20\u9053\u90e8","Pshuzi":"1638000","children":[{"id":"4","Pid":"1","Pname_ch":"\u9500\u552e\u4e8c\u90e8","Pshuzi":"895000","children":[{"id":"13","Pid":"4","Pname_ch":"\u5468\u7ecf\u7406","Pshuzi":"28","children":[{"id":"28","Pid":"13","Pname_ch":"\u6e56\u5357","Pshuzi":"158000"},{"id":"35","Pid":"13","Pname_ch":"\u65b0\u7586","Pshuzi":"19000"}]},{"id":"40","Pid":"4","Pname_ch":"\u9648\u7ecf\u7406","Pshuzi":"5000"}]}]}]', true)

//$tree是具有父子关系的数据树

sumShuzi($tree, $updateData)

foreach ($updateData as $id => $item) {

  $sql = "update your_table set Pshuzi={$item[0]} where id={$id}"

  mysqli_query($db, $sql)    //$db是你的数据库连接结果

}

使用聚和函数 sum() 求和

select sum(money) from record t where t.name = ?

注意：t 是一个表的别名，比如 t.name 就是取 record 表中的name，使用 record.name 也可以，但就是太长了，所以起一个别名比较方便

扩展资料：

聚集函数是 AVG、COUNT、MAX、MIN 和 SUM，以下示例中描述了聚集函数的语法

aggregation-function ( [ ALL | DISTINCT ] expression )

或：COUNT( [ ALL | DISTINCT ] identification-variable )

或：COUNT( * )

在应用函数之前，DISTINCT 选项消除重复值。

参考资料来源：百度百科-聚集函数

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