merge two rows with same id but different column values into one row [mysql]

Question

I have joined two tables and obtained a resultset that has different rows for the same id or say, type, but they have different column values.

Eg.

leave_type  |  max Days  |  jan  |  feb  |  mar  |  apr
Personal    |  12        |  0.00 |  0.00 |  2.00 |  0.00
Personal    |  12        |  1.00 |  0.00 |  0.00 |  0.00
Sick        |  5         |  0.00 |  0.00 |  1.00 |  0.00

I would like the result as follows:

leave_type  |  max Days  |  jan  |  feb  |  mar  |  apr
Personal    |  12        |  1.00 |  0.00 |  2.00 |  0.00
Sick        |  5         |  0.00 |  0.00 |  1.00 |  0.00

How can this be done in mysql?

Any help is very much appreciated. Thanks.

Answer 1

You can use GROUP BY and aggregate functions.

SELECT
    `leave_type`,
    MAX(`days`) AS `max_days`,
    MAX(`jan`) AS `jan`,
    MAX(`feb`) AS `feb`,
    MAX(`mar`) AS `mar`,
    MAX(`apr`) AS `apr`
FROM
    `table`
GROUP BY
    `leave_type`

It's not clear whether you want to use MAX or SUM from your example, but you can use either, depending on your goal.

Answer 2

You can just use an aggregation query:

select leave_type, maxDays,
       sum(jan) as jan, sum(feb) as feb, sum(mar) as mar, sum(apr) as apr
from t
group by leave_type, maxDays ;