CODEWITHSUNDEEP
mysqlsqlselectdistinctgroup-concat
Kevin O.
Kevin O.

Reputation: 79

Grouping together results of multiple GROUP_CONCAT() with distinct values only

second attempt at this question with more detail. I am attempting to group the distinct values of multiple columns together for objects of the same name. I can use GROUP_CONCAT on each of the 'Type' columns, but I can't merge them together to get a distinct set of values for each name

Here is a sample of my data:

+----------+-------+-------+-------+
| Company  | Type1 | Type2 | Type3 |
+----------+-------+-------+-------+
| Generic  | 1     | NULL  | 3     |
+----------+-------+-------+-------+
| Generic  | NULL  | 2     | 2     |
+----------+-------+-------+-------+
| Generic  | 3     | 2     | NULL  |
+----------+-------+-------+-------+
| Generic2 | 1     | NULL  | NULL  |
+----------+-------+-------+-------+
| Generic2 | NULL  | 2     | 2     |
+----------+-------+-------+-------+
| Generic2 | 1     | 2     | NULL  |
+----------+-------+-------+-------+

And here is the basic query I have to come up with that does NOT work as desired:

SELECT s.company, CONCAT(GROUP_CONCAT(DISTINCT s.type1),',',GROUP_CONCAT(DISTINCT s.type2),',',GROUP_CONCAT(DISTINCT s.type3)) AS GROUPED
FROM sample s
GROUP BY s.company

The above query returns:

+----------+-----------+
| Company  | GROUPED   |
+----------+-----------+
| Generic  | 1,3,2,3,2 |
+----------+-----------+
| Generic2 | 1,2,2     |
+----------+-----------+

What I need it to return is a grouping of the groups with distinct values only:

+----------+---------+
| Company  | GROUPED |
+----------+---------+
| Generic  | 1,2,3   |
+----------+---------+
| Generic2 | 1,2     |
+----------+---------+

Is this possible?

Upvotes: 0

Views: 806

Answers (1)

GMB
GMB

Reputation: 222442

One option is to unpivot the columns to rows before grouping. In MySQL, you can do this with union all:

select company, group_concat(distinct typex order by typex) res
from (
    select company, type1 typex from mytable
    union all select company, type2 from mytable
    union all select company, type3 from mytable
) t
group by company

Demo on DB Fiddle:

company  | res  
:------- | :----
Generic  | 1,2,3
Generic2 | 1,2

Upvotes: 2

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