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可以直接使用mysql的sum函数求和,mysql会自动转换为数字型进行求和.
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php+mysql,
举个例子
...........省略数据库连接3步骤
$sql
=
"select
sum(price)
from
table";
//查询price字段下所有值的和
$query
=
mysql_query($sql);
//执行sql语句
$result
=
mysql_fetch_row($query);
//取得搜索结果中的数据(一个数组)
echo
$result[0];
//
数组中只有一条数据,所以索引
就可以了
echo就是显示啦,
希望能帮到你
SELECT SUM(分数) FROM 表a WHERE 性别='男'
SELECT SUM(分数) FROM 表a WHERE 性别='女'
----测试
CREATE TABLE MASK_TEST(
ID INT,
姓名 varchar(20),
性别 varchar(20),
年龄 int,
分数 int
)
INSERT INTO MASK_TEST VALUES(11,'ZHANG SAN','男',20,88)
INSERT INTO MASK_TEST VALUES(11,'LIU SHAN','女',20,83)
INSERT INTO MASK_TEST VALUES(11,'WANG SAN','男',20,87)
INSERT INTO MASK_TEST VALUES(11,'ZHANG TING','女',20,83)
INSERT INTO MASK_TEST VALUES(11,'ZHAO YAN','女',20,88)
INSERT INTO MASK_TEST VALUES(11,'ZHOU HU','男',20,78)
INSERT INTO MASK_TEST VALUES(11,'WANG QIANG','男',20,98)
INSERT INTO MASK_TEST VALUES(11,'LI QIAN','女',21,68)
SELECT SUM(分数) FROM MASK_TEST WHERE 性别='男'
SELECT SUM(分数) FROM MASK_TEST WHERE 性别='女'
----结果：
(1 行受影响)
(1 行受影响)
(1 行受影响)
(1 行受影响)
(1 行受影响)
(1 行受影响)
(1 行受影响)
(1 行受影响)
-----------
351
(1 行受影响)
-----------
322
(1 行受影响)
function sumShuzi($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
}