MySQL 跨行和多列对 select 中的值进行评分

Question

So I have a scheme like the following:

| phone1        | phone2      | phone3      | phone4        | phone5      | phone6        |
| ------------- | ----------- | ----------- | ------------- | ----------- | ------------- |
|  447488575023 | 07488575023 | 07397005898 |  441535930275 | 01535930275 |  07397005898  |
| 01606592390   | 07968233423 | 07968233423 | 01606592490   | 07968233423 |  441606592490 |
| 01606592390   | 07968233423 | 07968233423 | 01606592490   | 07968233423 |  441606592490 |
|  447544737701 | 07544737701 | 07544737701 | 07544737701   | 07587989521 |  447402204547 |
|  447383626815 | 07383626815 | 07383626815 | 07383626815   | 07508889595 |  447412987535 |
|  441752313756 | 01752313756 | 07958697492 | 01752313756   | 07746624841 |  447958437692 |
|  447784301122 | 07784301122 | 07784301122 | 07784301122   | 07732274851 |  447979879900 |

What I want to achieve is to get the top 6 unique occurring numbers in order of the count across all rows and columns.

Answer 1

You need to unpivot. In MySQL, this is typically done using union all :

select phone, count(*)
from ((select phone1 as phone from t) union all
      (select phone2 as phone from t) union all
      (select phone3 as phone from t) union all
      (select phone4 as phone from t) union all
      (select phone5 as phone from t) union all
      (select phone6 as phone from t) 
     ) p
group by phone
order by count(*) desc
limit 1;