将两个选择的SQL查询合并为一个

Question

"id"    "type"  "parent"    "country"   "votes" "perCent"
"1"     "1"     "0"         "US"        "0"     "0"
"2"     "3"     "1"         "US"        "105"   "0"// Total
"3"     "10"    "2"         "US"        "15"    "0"
"4"     "10"    "2"         "US"        "50"    "0"
"5"     "10"    "2"         "US"        "25"    "0"
"6"     "10"    "2"         "US"        "5"     "0"
"7"     "10"    "2"         "US"        "10"    "0"

"8"     "1"     "0"         "US"        "0"     "0"
"9"     "3"     "8"         "US"        "80"    "0"// Total
"10"    "10"    "9"         "US"        "10"    "0"
"11"    "10"    "9"         "US"        "5"     "0"
"12"    "10"    "9"         "US"        "15"    "0"
"13"    "10"    "9"         "US"        "20"    "0"
"14"    "10"    "9"         "US"        "30"    "0"

在上面的表likes ，我将总票数存储在type = 3行中。

我试图用类型= 10的每个投票百分比更新perCent列。

我现在在php中执行以下操作。 前两个语句可以合并为一个吗？ 我迷失了联接和内部联接等的尝试。

我目前在php中做事的方式如下：

select id, votes as totalVotes from likes where type = 3 and country = 'us';

select votes from likes where parent = id and type = 10;

update votes set votes = (100*10/totalVotes) where type = 10 and parent = id;

我试图达到的结果：

"id"    "type"  "parent"    "country"   "votes" "perCent"
    "1"     "1"     "0"         "US"        "0"     "0"
    "2"     "3"     "1"         "US"        "105"   "0"// Total
    "3"     "10"    "2"         "US"        "15"    "14.28" (100*15/105)
    "4"     "10"    "2"         "US"        "50"    "47.61"
    "5"     "10"    "2"         "US"        "25"    "23.80"
    "6"     "10"    "2"         "US"        "5"     "4.76"
    "7"     "10"    "2"         "US"        "10"    "9.53"

    "8"     "1"     "0"         "US"        "0"     "0"
    "9"     "3"     "8"         "US"        "80"    "0"// Total
    "10"    "10"    "9"         "US"        "10"    "12.5"
    "11"    "10"    "9"         "US"        "5"     "6.25"
    "12"    "10"    "9"         "US"        "15"    "18.75"
    "13"    "10"    "9"         "US"        "20"    "25.00"
    "14"    "10"    "9"         "US"        "30"    "37.50"

Answer 1

检查SQLFiddle 。

UPDATE `votestable` v
SET v.`percent` = (SELECT
                     ROUND( ( ( v.votes * 100) / v1.votes ), 2 )
                   FROM (SELECT
                           votes,
                           id
                         FROM Votestable) AS v1
                   WHERE v1.id = v.parent)

Answer 2

这应该按照您的要求执行，更新所有产品的百分比，以反映其标题下总投票的部分；

UPDATE likes p
JOIN likes h
  ON p.parent = h.id
 AND p.type=10 AND h.type=3
 AND h.country = 'US'
SET p.percent=100*p.votes/h.votes;

要使用进行测试的SQLfiddle 。

Answer 3

如果我没记错的话，这就像是我的左撇子。

SELECT lp.id, lp.votes + COALESCE(SUM(lc.votes), 0) as totalVotes FROM likes lp
    LEFT JOIN likes lc ON lc.parent = lp.id AND lc.type = 10
    WHERE lp.type = 3 AND lp.country = 'us'