pardon my question title, I'm not sure what should I put it, I have these two tables as below.
products orders
+------+----------+ +--------+------+-------+
| id | name | | id | qty | pid |
+------+----------+ +--------+------+-------+
| 1 | mouse | | 10001 | 20 | 1 |
| 2 | keyboard | | 10002 | 15 | 3 |
| 3 | headset | | 10004 | 5 | 3 |
+------+----------+ | 10005 | 12 | 2 |
| 10006 | 18 | 1 |
+--------+------+-------+
This is the LEFT JOIN query I am using and the output
SELECT p.id AS No, p.name AS ProductName, o.qty AS Quantity
FROM products AS p
LEFT JOIN orders AS o ON p.id = o.pid
+------+-------------+----------+
| No | ProductName | Quantity |
+------+-------------+----------+
| 1 | mouse | 20 |
| 1 | mouse | 18 |
| 2 | keyboard | 12 |
| 3 | headset | 15 |
| 3 | headset | 5 |
+------+-------------+----------+
What I am trying to achieve is an output as below:
+------+-------------+----------+
| No | ProductName | Quantity |
+------+-------------+----------+
| 1 | mouse | 20 |
| | | 18 |
| 2 | keyboard | 12 |
| 3 | headset | 15 |
| | | 5 |
+------+-------------+----------+
My question is it possible to do so? Any reply and suggestions is greatly appreciate. Thanks.
P/S: I also have tried using the GROUP_CONCAT(qty SEPARATOR ",") but it returns the result in one row as I may have more additional column to add in the Orders table in the future and it will be difficult to read.
In this case you can use MySQL variables. I store the previous product id in the variable @prev, and only if it changes we output the product name.
http://www.sqlfiddle.com/#!2/d5fd6/9
SET @prev := NULL;
SELECT
IF( @prev = p.id, NULL, p.id) AS No,
IF( @prev = p.id, NULL, p.name) AS ProductName,
o.qty AS Quantity
,@prev := p.id
FROM products AS p
LEFT JOIN orders AS o
ON p.id = o.pid