MySQL - How to display row value as column name using concat and group_concat

Question

Table 1:

id   | typeid | available|
0    | 1      | 12       |
0    | 2      | 44       |

Table 2:

<

Answer 1

It can be done only if you know all the typenames in advance -- otherwise, you'll need to find another way. In databases that support returning result sets from stored procedures, it could be done with a stored proc. But mysql doesn't support that.

If you know all the typenames, here's how you build the query:

SELECT
    id,
    SUM(IF(typename = 'CL', available, 0)) AS `CL`,
    SUM(IF(typename = 'ML', available, 0)) AS `ML`
FROM table1 join table2 on table1.typeid = table2.typeid
GROUP BY id