I have DB with two tables:
rmonth and alternatives
The rmonth is an aggregated table of data for each alternative a complete month - if they have any - otherwise the row don't exist in the rmonth table.
Now I want to join them, and this is my code:
SELECT
COALESCE(rmAntal, 0) AS sumMonth, aID, aText, rmUnitID
FROM
alternatives
LEFT JOIN
rmonth ON aID = rmAltID
WHERE aToQuestID = 4418
AND rmMonth = 3
AND rmYear = 2018
AND rmUnitID IN (10603,10960,10496)
GROUP BY aID, rmUnitID
ORDER BY aID ASC
But it doesn't give me the rows not existing in rmonth.
So this scenario gives me the result as I want it - except that it can't handle where the alternative does not exist for that specific unitID in rmonth.
I want them listed with just 0 in sumMonth.
Unfortunately that's where my MySQL-knowledge is limited.
Thanks.
You could add an OR operator, for example
...
WHERE aToQuestID = 4418 AND rmMonth IS NULL OR (
AND rmMonth = 3
AND rmYear = 2018
AND rmUnitID IN (10603,10960,10496)
)
...
This way, you'll get all your alternatives data, even when it's counter part in rmonth is null.
Related
let's say I have 4 tables
The requirements are:
If a supplier accepted an order then in the orders_suppliers table the order_supplier_status_id change to 3 .
If all suplliers associated to a specific combined order accepted their orders then in the Combined_orders table
the Combined_order_status_id change to 3.
If at least one supplier accepted an order and all order are not accepted than in the table Combined_orders the
Combined_order_status_id change to 2.
My question is: Is it possible in one query to update the Combined_order_status_id to accepted only if all suppliers accepted their orders ?
something like:
update Combined_orders
set Combined_orders.Combined_order_status_id = 3 if(all orders_suppliers.order_supplier_status_id == 3 )
otherwise
set Combined_orders.Combined_order_status_id = 2
where orders_suppliers.Combined_order_id = Combined_orders.Combined_order_id
Each time a supplier accept an order , I would like to execute this query.
For now I didn't find a way to do that in only one query. It is reaaly important for me to do that in one query , because from what I understand if is made in one query it would be an atomic operation.
You can use join and an aggregation:
update Combined_orders co join
(select os.combined_order_id, min(os.order_supplier_status_id) as min_ossi,
max(os.order_supplier_status_id) as max_ossi
from orders_suppliers os
group by os.combined_order_id
) os
on os.combined_order_id = co.combined_order_id
set co.Combined_order_status_id = (case when min_ossi = max_ossi and min_ossi = 3 then 3 else 2 end);
Overview
I have two tables as can be seen below:
user_planes
----------------------------------
|id |user_id|plane_id|fuel|status|
----------------------------------
| 2 1 1 1 Ready |
----------------------------------
shop_planes
------------------------
|id |name|fuel_capacity|
------------------------
| 1 bob 3 |
------------------------
Foreign Key Primary Key
user_planes.plane_id <-> shop_planes.id
I want to be able to get every field (SELECT *) in user_planes and name and fuel_capacity based on the following criteria:
WHERE user_planes.user_id = ? - Parameter which will be added to the query through PHP.
WHERE user_planes.status = 'Ready'
WHERE user_planes.fuel < shop_planes.fuel_capacity
The Issue and My Attempts
I've tried JOIN however it retrieves data which doesn't fit that criteria, meaning it gets extra data which is from shop_planes and not user_planes.
SELECT * FROM `user_planes` WHERE fuel IN (SELECT shop_planes.fuel_capacity FROM shop_planes WHERE fuel < shop_planes.fuel_capacity) AND user_planes.user_id = 1 AND status = 'Ready'
and
SELECT * FROM `user_planes` INNER JOIN `shop_planes` ON user_planes.fuel < shop_planes.fuel_capacity AND user_planes.user_id = 1 AND user_planes.status = 'Ready'
I've searched Stackoverflow and looked through many questions but I've not been able to figure it.
I've looked up many tutorials but still can't get the desired result.
The desired result is that the query should use the data stored in user_planes to retrieve data from shop_planes while at the same time not getting any excess data from shop_planes.
Disclaimer
I really struggle using JOIN queries, I could use multiple separate queries however I wish to optimise my queries hence I'm trying to bring it in to one query.
If their isn't clarity in the question, please do say, I'll update it to the best of my ability.
Note - Is there an easy query builder option available either through phpmyadmin or an alternative software?
Thanks in advance.
Your last attempt was not a bad one, the only thing you missed there was the join criteria you described at the beginning of your post. I also moved the other filters to the where clause to better distinguish between join condition and the filters.
SELECT `user_planes`.*
FROM `user_planes`
INNER JOIN `shop_planes` ON user_planes.plane_id = shop_planes.id
WHERE user_planes.fuel < shop_planes.fuel_capacity AND user_planes.user_id = 1 AND user_planes.status = 'Ready'
First you need the base JOIN
SELECT up.* -- only user_plane fields
FROM shop_planes sp -- CREATE alias for table or field
JOIN user_planes up
ON sp.id = up.plane_id
Case 1: apply a filter in where condition with php parameter.
SELECT up.*
FROM shop_planes sp
JOIN user_planes up
ON sp.id = up.plane_id
WHERE up.user_id = ?
Case 2: apply a filter in where condition with string constant
SELECT up.*
FROM shop_planes sp
JOIN user_planes up
ON sp.id = up.plane_id
WHERE user_planes.status = 'Ready'
Case 3: aply filter comparing fields from both tables
SELECT up.*
FROM shop_planes sp
JOIN user_planes up
ON sp.id = up.plane_id
WHERE up.fuel < sp.fuel_capacity
Try something like:
SELECT
up.id AS User_Plane_ID
, up.[user_id]
, up.plane_id
, up.fuel
, up.[status]
, sp.name AS shop_Plane_Name
, sp.fuel_capacity AS shop_Plane_Fuel_Capacity
FROM User_Planes up
INNER JOIN Shop_Planes sp ON up.plane_id = sp.id
AND up.fuel < sp.Fuel_Capacity
WHERE up.[status] = 'Ready'
AND up.[user_id] = ?
Definitely find a tutorial for JOINs, and don't use SELECT *. With SELECT *, you may end up querying much more than you actually need and it can cause problems if the table changes. You'll enjoy your day much more if you explicitly name the columns you want in your query.
I've aliased some of the columns (with AS) since some of those column names may be reserved words. I've also moved the JOIN criteria to include a filter on fuel
Please can someone talk me through a query that I have inherited through a website I am developing.
The query is returning a random group of 5 products based on the category number 56. There is an issue with the query because it is not restricting the selection based on the product on web and product archive conditions.
AND p.product_OnWeb = 1
AND p.product_Archive = 0
The above lines in the query aren't being adhered to. Instead the query is including all products even when they are marked as p.product_Archive=1 (Archived) and p.product_OnWeb = 0 (Not Online)
If someone could point out where I need to make a change I'd be grateful.
The query in full is:-
SELECT c.prdt_cat_rel_Product_ID,
ROUND(RAND() * x.m_id) 'rand_ind'
FROM tbl_prdtcat_rel c,
tbl_products p,
(SELECT MAX(t.prdt_cat_rel_Cat_ID) 'm_id'
FROM tbl_prdtcat_rel t) x
WHERE c.prdt_cat_rel_Cat_ID = 56
AND p.product_OnWeb = 1
AND p.product_Archive = 0
ORDER BY rand_ind
LIMIT 3
Thankyou
First, to make it easier, convert the query to the newer join syntax
SELECT c.prdt_cat_rel_Product_ID, ROUND(RAND() * x.m_id) 'rand_ind'
FROM tbl_prdtcat_rel c,
JOIN tbl_products p ON p.??? = c.???
JOIN (
SELECT MAX(t.prdt_cat_rel_Cat_ID) 'm_id' FROM tbl_prdtcat_rel t
) x ON 1=1
WHERE c.prdt_cat_rel_Cat_ID = 56
AND p.product_OnWeb = 1
AND p.product_Archive = 0
ORDER BY rand_ind
LIMIT 3
You can see that the query doesn't know how to select match records from P based on C, so it grabs them all.. You need to specify how to match tbl_prdtcat records with tbl_product records (replace the ??? in the above with the appropriate fields)
I am guessing each product in p has some sort of field indicating which category it belong to, use this field to match and your query should work...
I'm building a report for a database where I need to determine the number of "first scans" grouping by company, job, and date.
The scan table can contain multiple scans for the same item, however I only want to include the original scan in my COUNT, which can only be identified as being the scan with the earliest date that matches a particular item.
My first attempt at this was:
SELECT
_item_detail.job_id,
_item_group.group_id,
_scan.company_id,
DATE(scan_date_time) as scan_date,
COUNT(1)
FROM _scan
INNER JOIN _item_detail ON _item_detail.company_id = _scan.company_id
AND
_item_detail.serial_number = _scan.serial_number
INNER JOIN _item_group ON _item_group.group_id = _item_detail.group_id
WHERE _item_detail.job_id = '0326FCM' AND _scan.company_id = '152345' AND _item_group.group_id = 13
GROUP BY
_item_detail.job_id,
_item_group.group_id,
_scan.company_id, scan_date -- first_scan_count
HAVING min(scan_date_time);
This is giving me incorrect results, though (about 3x too many). I am assuming it's because the MIN record is being recalculated for each date, so if the min was found on day 1, it may also be found on day 3 and counted again.
How can I modify my query to achieve the desired results?
Something similar to this should work... I'm not completely sure of how your tables are laid out or how the data relates them together, but this is the general idea:
SELECT
_item_detail.job_id,
_item_group.group_id,
_scan.company_id,
DATE(scan_date_time) as scan_date,
COUNT(1)
FROM
_scan s1
INNER JOIN _item_detail
ON _item_detail.company_id = s1.company_id
AND _item_detail.serial_number = s1.serial_number
AND _item_detail.job_id = '0326FCM'
INNER JOIN _item_group
ON _item_group.group_id = _item_detail.group_id
AND _item_group.group_id = 13
WHERE
s1.company_id = '152345'
AND s1.scan_date_time = (
SELECT MIN(s2.scan_date_time)
FROM _scan s2
WHERE
s2.company_id = s1.company_id
AND s2.serial_number = s1.serial_number
)
GROUP BY
_item_detail.job_id,
_item_group.group_id,
s1.company_id
I don't quite follow your query, but based on the description of the problem, I'd say create a subquery that gives the min scan date for for each item, group by items, the perform your outer select on that.
I have two separate SELECT statements:
SELECT VCe.VId FROM `VCe` WHERE `YId` = 9007 AND `MaId` =76 AND `MoId` = 2851
SELECT r_pts.p_id FROM r_pts WHERE r_pts.v_id IN (57202, 57203, 69597, 82261, 82260, 69596, 69595, 82259)
When they are run separately they both complete in under .05sec however when I nest the first one within the second, it dramatically increases to 3.3sec.
I would like to do a join so that I can get the output from the second SELECT using the first select as the result set for the IN() but I cannot figure out how to include WHERE conditions in a JOIN.
Edit: Also what is the correct syntax to do a join as I am requesting?
Thanks for your help, its appreciated!
Equivalent to MattMcKnight's query whilst illustrating "how to include WHERE conditions in a JOIN":
SELECT r.p_id
FROM r_pts r
INNER JOIN VCe v
ON v.VId = r.v_id
AND
v.YId = 9007
AND
v.MaId = 76
AND
v.MoId = 2851
SELECT r_pts.p_id FROM r_pts, 'VCe' WHERE r_pts.v_id = VCe.VId AND VCe.YId = 9007 AND VCe.MaId =76 AND VCe.MoId = 2851
The basic goal of a join is to describe how the two tables relate. I inferred from your example that the v_id column in the r_pts table was a foreign key pointing to the VId primary key in the VCe table. When you add a term in the query (such as "r_pts.v_id = VCe.VId") that has a field from each table you wish to join, that tells the database how to match up the rows between the tables to make "virtual rows" that contain the columns from both tables. Your other query terms limit which rows are included in the result set.