php/mysql - 比较 2 个表中的多个列并显示最大差异

Question

我有 1 个包含我所有信息的主要 table 和 1 个具有几乎相同结构但值略有不同的 table。现在我想比较这些值并得到最高的差异。我通过对每一列 (a1-a5) 的查询来处理这个问题，在每个查询的循环中我再次查询并对结果进行一些计算......我不知道，它很乱，我不知道如何得到这个以一种干净的方式。

这是2个table的结构：

+----------+----------+--------+-----+-----+-----+-----+-----+--------------+
| HomeTeam | AwayTeam | Result |  a1 |  a2 |  a3 |  a4 |  a5 |  Date        |
+----------+----------+--------+-----+-----+-----+-----+-----+--------------+
| team1    | team2    |      H |  5  |  2  |  4  |  4  |  3  |  11-04-2017  |
| team3    | team4    |      A |  6  |  8  |  4  |  2  |  6  |  11-04-2017  |
| team1    | team3    |      D |  3  |  7  |  9  |  7  |  2  |  12-04-2017  |
| team4    | team2    |      H |  2  |  4  |  8  |  6  |  5  |  12-04-2017  |
+----------+----------+--------+-----+-----+-----+-----+-----+--------------+

+----------+----------+-----+-----+-----+-----+-----+
| HomeTeam | AwayTeam |  a1 |  a2 |  a3 |  a4 |  a5 |
+----------+----------+-----+-----+-----+-----+-----+
| team1    | team2    |  2  |  3  |  5  |  3  |  3  |
| team3    | team4    |  5  |  7  |  5  |  2  |  3  |
| team1    | team3    |  4  |  2  |  8  |  6  |  5  |
| team4    | team2    |  2  |  5  |  5  |  6  |  4  |
+----------+----------+-----+-----+-----+-----+-----+

这就是我要打印的内容：

team 1 vs team 2 biggest increase was 150% (a1 -> 5 vs 2) on 11-04-2017 
team 3 vs team 4 biggest increase was 100% (a5 -> 6 vs 3) on 11-04-2017 
team 1 vs team 3 biggest increase was 250% (a2 -> 7 vs 2) on 12-04-2017 
team 4 vs team 2 biggest increase was 60% (a3 -> 8 vs 5) on 12-04-2017

当我输入这个时，我在想也许只使用一个查询从两个 table 中获取所有内容并使用这些值进行一些计算？不确定..有人可以在正确的方向上给我很大的帮助吗？

Answer 1

我们可以在这里使用GREATEST来找到每场比赛的最大点差：

SELECT
    HomeTeam,
    AwayTeam,
    GREATEST(t1.a1 - t2.a1, t1.a2 - t2.a2, t1.a3 - t2.a3, t1.a4 - t2.a4, t1.a5 - t2.a5) AS max_diff
FROM table1 t1
INNER JOIN table2 t2
    ON t1.HomeTeam = t2.HomeTeam AND t1.AwayTeam = t2.AwayTeam;

如果您还需要实际的 a 值，那么工作量会增加很多，尤其是考虑到您的数据未标准化。对于比上述更复杂的任何事情，您可能想要规范化数据。

php/mysql - 比较 2 个表中的多个列并显示最大差异

php/mysql - Compare multiple columns from 2 tables and show biggest differnce

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