How to group mysql rows with same column value into one row?
I have two tables, keywords and data.
Table keywords have 2 columns (id, keyword), table data have 3 columns (id[foreign key of keywords.id], name, value).
I am using this query:
SELECT k.id, d.value, d.name
FROM keywords AS k
INNER JOIN data as d ON k.id = d.id
it returns something like:
1 123 name1
1 456 name2
2 943 name1
3 542 name1
3 532 name2
3 682 name3
Each id can have values from 0 to 3 (maybe more in the future).
How can I retrieve all the rows with the same id in the same row?
Like
1 123 456
2 943
3 542 532 682
I want to do this because I want to be able to sort the values.
Solution 1:
Use GROUP_CONCAT()
like this:
SELECT k.id, GROUP_CONCAT(d.value)
FROM keywords AS k
INNER JOIN data as d ON k.id = d.id
GROUP BY k.id
Also, you may need to do ORDER BY d.name
to get exact order of values as you want. Like this:
SELECT k.id, GROUP_CONCAT(d.value ORDER BY d.name separator ' ')
FROM keywords AS k
INNER JOIN data as d ON k.id = d.id
GROUP BY k.id