在mysql中找到三个具有相同值的列

Question

我有多个列具有相同的值。我想找到超过3列的行ID具有相同的值。

@each column is text/blob

表结构类似于 -

id  col1 col2 col3 col4 col5 col6 col7 col8 col9

Answer 1

Unpivot数据并检查是否相等，试试这个技巧。

SELECT DISTINCT id 
FROM   (SELECT id,col1 AS col from Yourtable
        UNION ALL 
        SELECT id,col2  from Yourtable
        UNION ALL 
        SELECT id,col3  from Yourtable
        UNION ALL 
        SELECT id,col4  from Yourtable
        Union ALL
        .......) A 
GROUP  BY id,col 
HAVING Count(1) > 3