left join doesn't return all rows Mysql

Question

I have a table that has greenhouse information

pr_grouper_details

--------------------------------------------------------
  id  |  grouper_detail | status | periphery | id_tenant
--------------------------------------------------------
  1   |       1         |   100  |     0     |    1    
-------------------------------------------------------
  1   |       2         |   100  |     0     |    1    
-------------------------------------------------------
  1   |       3         |   100  |     0     |    1    
-------------------------------------------------------
  1   |       4         |   100  |     0     |    1    
-------------------------------------------------------

I have this table that has the sowings of each of the greenhouses:

---------------------------------------------------------
  id  |  id_grouper_detail  | id_product  | type | status
---------------------------------------------------------
  1   |          1          |    1        |  SW  |  100
-------------------------------------------------------- 
  1   |          1          |    2        |  SW  |  100
-------------------------------------------------------- 
  1   |          2          |    1        |  SW  |  100
-------------------------------------------------------- 
  1   |          3          |    1        |  SW  |  100
-------------------------------------------------------- 

This the table with the information of products:

----------------------------
 id  |   product  | status |
----------------------------
  1  |   FLOWER1  |  100   |
---------------------------- 
  2  |   FLOWER2  |  100   |
---------------------------- 

I need to bring all the greenhouses regardless of whether you have products or not, but only bring me those that have products:

SELECT id, grouper_detail, GROUP_CONCAT(product SEPARATOR ' - ') AS products
FROM(
                    SELECT pr_grouper_details.id, pr_grouper_details.grouper_detail, pr_products.product
     FROM sw_sowing
                    INNER JOIN pr_products ON pr_products.id = sw_sowing.id_product
     LEFT JOIN pr_grouper_details ON pr_grouper_details.id = sw_sowing.id_grouper_detail
     AND pr_grouper_details.status = 100
     AND pr_grouper_details.periphery = 0
                    AND pr_grouper_details.id_tenant = 1
                    WHERE sw_sowing.type = 'SW'
                    AND sw_sowing.status = 100
                    GROUP BY pr_grouper_details.id, pr_products.id
) AS s
GROUP BY id

This is the result

----------------------------------------------
  id |   grouper_detail |  products 
----------------------------------------------
  1  |         1        |  FLOWER1 - FLOWER2  
----------------------------------------------
  2  |         2        |  FLOWER1  
----------------------------------------------
  3  |         3        |  FLOWER1  
----------------------------------------------

But I need something like this:

----------------------------------------------
  id |   grouper_detail |  products 
----------------------------------------------
  1  |         1        |  FLOWER1 - FLOWER2  
----------------------------------------------
  2  |         2        |  FLOWER1  
----------------------------------------------
  3  |         3        |  FLOWER1  
----------------------------------------------
  4  |         4        |  NULL  
----------------------------------------------

I am using LEFT JOIN but it doesn't work, I hope that you can help me!

Answer 1

Your subquery would be much easier to follow with table aliases. You have the filtering conditions correct in the ON clause. However, you are aggregating by pr_grouper_details.id and this could be NULL .

Instead use the equivalent column s.id_grouper_detail . Then, I think you need to start with pr_grouper_details because you want to keep all of those rows. The ON s and WHERE clauses need to be adjusted:

SELECT s.id_grouper_detail, p.product
FROM pr_grouper_details gd LEFT JOIN
     sw_sowing s
     ON gd.id = s.id_grouper_detail AND
        s.type = 'SW' AND
        s.status = 100 LEFT JOIN
     pr_products p
     ON p.id = s.id_product
WHERE gd.status = 100 AND
      gd.periphery = 0 AND
      gd.id_tenant = 1
GROUP BY s.id_grouper_detail, p.product;

You have gd.id in your original query. That is a bad idea.

Answer 2

Try this one:

SELECT gd.grouper_detail, GROUP_CONCAT(product SEPARATOR ' - ') AS products
FROM pr_grouper_details gd LEFT JOIN
    sw_sowing s
ON gd.grouper_detail = s.id_grouper_detail AND
    s.type = 'SW' AND
    s.status = 100 LEFT JOIN
    pr_products p
ON p.id = s.id_product
WHERE gd.status = 100 AND
    gd.periphery = 0 AND
    gd.id_tenant = 1
GROUP BY s.id_grouper_detail