Want to Merge two rows into one using MySQL group_concat

Question

i want to merge 2 rows as one using group_concat mysql query

$query = $this->db->select('trt.day, group_concat(trt.open_time, trt.close_time)')
                          ->from('tbl_restaurant_timing as trt')
                          ->where('trt.restaurant_id', $restaurant_id, FALSE)
                          ->group_by('trt.day')
                          ->get();

I have tried the above one but it provide some other result like below

Array
(
    [0] => Array
        (
            [day] => Fri
            [group_concat(trt.open_time, trt.close_time)] => 18:0023:00,10:0015:00
        )

    [1] => Array
        (
            [day] => Mon
            [group_concat(trt.open_time, trt.close_time)] => 10:0015:00,18:0023:00
        )

    [2] => Array
        (
            [day] => Sat
            [group_concat(trt.open_time, trt.close_time)] => 18:0023:00,10:0015:00
        )

    [3] => Array
        (
            [day] => Sun
            [group_concat(trt.open_time, trt.close_time)] => 10:0015:00,18:0023:00
        )

    [4] => Array
        (
            [day] => Thu
            [group_concat(trt.open_time, trt.close_time)] => 10:0015:00,18:0023:00
        )

    [5] => Array
        (
            [day] => Tue
            [group_concat(trt.open_time, trt.close_time)] => 18:0023:00,10:0015:00
        )

    [6] => Array
        (
            [day] => Wed
            [group_concat(trt.open_time, trt.close_time)] => 18:0023:00,10:0015:00
        )

)

Here you can see the 2nd slot comes first in some rows which is wrong.

This one my table i want result in php table like below

So Please check where i am wrong. Thank you

Answer 1

Please find below mentioned solutions, Bit lengthy operation but I think this will help you.

SELECT 
    trt.id,
    trt.day, 
    (SELECT CONCAT_WS('-',open_time, close_time) from tbl_restaurant_timing trt1 WHERE trt1.day = trt.day ORDER BY trt1.id ASC LIMIT 1) as first_slot,
    (SELECT CONCAT_WS('-',open_time, close_time) from tbl_restaurant_timing trt1 WHERE trt1.day = trt.day ORDER BY trt1.id DESC LIMIT 1) as second_slot
FROM tbl_restaurant_timing trt
WHERE trt.restaurant_id = 1
GROUP BY trt.day
ORDER BY id;

Table Data

+----+----------------+-----------+-----------+------------+
| id | restaurant_id  | day       | open_time | close_time |
+----+----------------+-----------+-----------+------------+
| 1  | 1              | Monday    | 10:00     | 15:00      |
+----+----------------+-----------+-----------+------------+
| 2  | 1              | Monday    | 18:00     | 23:50      |
+----+----------------+-----------+-----------+------------+
| 3  | 1              | Tuesday   | 09:00     | 15:00      |
+----+----------------+-----------+-----------+------------+
| 4  | 1              | Tuesday   | 18:00     | 23:00      |
+----+----------------+-----------+-----------+------------+
| 6  | 1              | Wednesday | 10:00     | 15:00      |
+----+----------------+-----------+-----------+------------+
| 7  | 1              | Wednesday | 18:00     | 23:00      |
+----+----------------+-----------+-----------+------------+
| 8  | 1              | Thursday  | 10:00     | 15:00      |
+----+----------------+-----------+-----------+------------+
| 9  | 1              | Thursday  | 18:00     | 23:00      |
+----+----------------+-----------+-----------+------------+
| 13 | 1              | Friday    | 10:00     | 15:00      |
+----+----------------+-----------+-----------+------------+
| 14 | 1              | Friday    | 18:00     | 23:00      |
+----+----------------+-----------+-----------+------------+
| 15 | 1              | Saturday  | 10:00     | 15:00      |
+----+----------------+-----------+-----------+------------+
| 16 | 1              | Saturday  | 18:00     | 23:00      |
+----+----------------+-----------+-----------+------------+
| 17 | 1              | Sunday    | 10:00     | 15:00      |
+----+----------------+-----------+-----------+------------+
| 18 | 1              | Sunday    | 18:00     | 23:00      |
+----+----------------+-----------+-----------+------------+

Result

+----+-----------+-------------+-------------+
| id | day       | first_slot  | second_slot |
+----+-----------+-------------+-------------+
| 1  | Monday    | 10:00-15:00 | 18:00-23:50 |
+----+-----------+-------------+-------------+
| 3  | Tuesday   | 09:00-15:00 | 18:00-23:00 | 
+----+-----------+-------------+-------------+
| 6  | Wednesday | 10:00-15:00 | 18:00-23:00 |  
+----+-----------+-------------+-------------+
| 8  | Thursday  | 10:00-15:00 | 18:00-23:00 | 
+----+-----------+-------------+-------------+
| 13 | Friday    | 10:00-15:00 | 18:00-23:00 | 
+----+-----------+-------------+-------------+
| 15 | Saturday  | 10:00-15:00 | 18:00-23:00 |
+----+-----------+-------------+-------------+
| 17 | Sunday    | 10:00-15:00 | 18:00-23:00 |
+----+-----------+-------------+-------------+

Let me know if it not works.