SQL many-to-many select help needed - sql

I have 2 tables
Bid_customer
|bidkey | customerkey
| 1 | 1
| 1 | 2
| 1 | 3
customer_groups
| groupkey | customerkey
| 1 | 1
| 1 | 2
| 1 | 3
What I'm trying to get is a result that will look like
| bidkey | groupkey
| 1 | 1
I've tried a cursor and joins but just don't seem to be able to get what i need any ideas or suggestions
EDIT: customers can belong to more that one group also

I am not sure who meaningful your sample data is. However following is a simple example.
Query:
select distinct b.bidkey, g.gkey
from bidcus b
inner join cusgroup g
on
b.cuskey = g.cuskey
and g.gkey = 10;
Results:
BIDKEY GKEY
1 10
Reference: SQLFIDDLE

In order to have a working Many-to-Many relationship in a database you need to have an intermediary table that defines the relationship so you do not get duplicates or mismatched values.
This select statement will join all bids with all groups because the customer matches.
Select bidkey, groupkey
From customer_groups
Inner Join bid_customer
Where customer_groups.customerkey = Bid_customer.customerkey
Hers is a sample Many to Many Relationship:
For your question:
You will need another table that joins the data. For example, GroupBids
customer_groups and bid_customer would have a one-to-many relationship with GroupBids
You would then do the following select to get your data.
Select bidkey, groupkey
From bid_customer
inner join GroupBids
ON bid_customer.primarykey = GroupBids.idBidKey
inner join customer_groups
ON customer_groups.primarykey = GroupBids.idCustomerGroupkey
This would make sure only related groups and bids are returned

Related

SQL Server avoid repeat same joins

I´m doing the query below where I´m repeating the same joins multiple times, there is a better way to do it? (SQL Server Azure)
Ex.
Table: [Customer]
[Id_Customer] | [CustomerName]
1 | Tomy
...
Table: [Store]
[Id_Store] | [StoreName]
1 | SuperMarket
2 | BestPrice
...
Table: [SalesFrutes]
[Id_SalesFrutes] | [FruteName] | [Fk_Id_Customer] | [Fk_Id_Store]
1 | Orange | 1 | 1
...
Table: [SalesVegetable]
[Id_SalesVegetable] | [VegetableName] | [Fk_Id_Customer] | [Fk_Id_Store]
1 | Pea | 1 | 2
...
Select * From [Customer] as C
left join [SalesFrutes] as SF on SF.[Fk_Id_Customer] = C.[Id_Customer]
left join [SalesVegetable] as SV on SV.[Fk_Id_Customer] = C.[Id_Customer]
left join [Store] as S1 on S1.[Id_Store] = SF.[Fk_Id_Store]
left join [Store] as S2 on S1.[Id_Store] = SV.[Fk_Id_Store]
In my real case, I have many [Sales...] to Join with [Customer] and many other tables similar to [Store] to join to each [Sales...]. So it starts to scale a lot the number on joins repeating. There is a better way to do it?
Bonus question: I do like also to have FruteName, VegetableName, StoreName, and each Food table name under the same column.
The Expected Result is:
[CustomerName] | [FoodName] | [SalesTableName] | [StoreName]
Tomy | Orange | SalesFrute | SuperMarket
Tomy | Pea | SalesVegetable | BestPrice
...
Thank you!!
So based on the information provided, I would have suggested the below, to use a cte to "fix" the data model and make writing your query easier.
Since you say your real-world scenario is different to the info provided it might not work for you, but could still be applicable if you have say 80% shared columns, you can just use placeholder/null values where relevant for unioning the data sets and still minimise the number of joins eg to your store table.
with allSales as (
select Id_SalesFrutes as Id, FruitName as FoodName, 'Fruit' as SaleType, Fk_Id_customer as Id_customer, Fk_Id_Store as Id_Store
from SalesFruits
union all
select Id_SalesVegetable, VegetableName, 'Vegetable', Fk_Id_customer, Fk_Id_Store
from SalesVegetable
union all... etc
)
select c.CustomerName, s.FoodName, s.SaleType, st.StoreName
from Customer c
join allSales s on s.Id_customer=c.Id_customer
join Store st on st.Id_Store=s.Id_Store

Getting results from two different tables using a join

Let's say I have the following tables:
+-------------------------------------------+
| t_classroom |
+-------------------------------------------+
| PK | id |
| | admin_user_id |
| | name |
| | students |
+-------------------------------------------+
+-------------------------------------------+
| t_shared |
+-------------------------------------------+
| | admin_user_id |
| | classroom_id |
| | expiry |
+-------------------------------------------+
I want to write a query that will pull all classrooms that an admin_user_id has access to. In essence, I want a union of classroom rows when I search by admin_user_id in the t_classroom table as well as classroom rows when I search by admin_user_id in the t_shared table. I made the following attempt:
SELECT
id,
admin_user_id,
name,
students
FROM
t_classroom
WHERE
admin_user_id = 1
UNION ALL
SELECT
c.id,
c.admin_user_id,
c.name,
students
FROM
t_classroom c
INNER JOIN t_shared s
ON c.id = s.classroom_id
WHERE
admin_user_id = 1
Does the above look correct? Is there anything more efficient/cleaner?
Depending on how much data you have you could probably get away with just using an IN clause to look at the other table.
SELECT
c.id,
c.admin_user_id,
c.name,
c.students
FROM
t_classroom c
WHERE
c.admin_user_id = 1
OR c.id IN ( select s.classroom_id from t_shared s where s.admin_user_id = 1 )
Your union wont work because you're left-joining to the t_shared table and checking only the classroom admin user.
If you join the shared room you would also end up with duplicates and would need to distinct the result too.
Edit:
Because of the large number of rows it might be better to use an exists check on the 2nd table.
SELECT
c.id,
c.admin_user_id,
c.name,
c.students
FROM
t_classroom c
WHERE
c.admin_user_id = 1
OR EXISTS ( select 1 from t_shared s where s.classroom_id = c.id AND s.admin_user_id = 1 )
Your solution is fundamentally fine, the only two problems I can detect when eyeballing your query are:
You need to write s.admin_user_id instead of admin_user_id in the last line to avoid an error message, because there is a column of that name in both tables. Best practice is to always qualify column names with the table names.
You might want to use UNION instead of UNION ALL if you want to avoid a duplicate result row in the case that both tables have admin_user_id = 1 for the same classroom.

combine 2 sql's from different tables into one query

I have for example as first query: (ararnr = article number)
Select ararnr,ararir,aoarom from ar left join ao ON AR.ARARNR=AO.AOARNR WHERE AR.ARARKD=1389
the second query uses the result from the first column from the first query to search in another table
Select votgan, sum(ststan) as totalStock from vo INNER JOIN st on vo.voarnr=st.starnr where voarnr = ararnr
How could I combine both ?
Please note : Not all articlenumbers from the first query will be found in the second, but I need them in my result.
In the result I need the columns from both queries.
EDIT
for example :
first query returns article numbers and the description:
+---------+--------------+
| ararnr | aoarom |
+---------+--------------+
| a123456 | description1 |
| b123456 | description2 |
| 0123456 | description3 |
+---------+--------------+
second query returns the totalstock for those articles:
+---------+--------------+
| ararnr | totalstock |
+---------+--------------+
| a123456 | 12 |
| b123456 | |
| 0123456 | 6 |
+---------+--------------+
Note the second one doesn't return a value since the articlenumber doesn't exist in this table.
In my result I would like to get the articlenumber with corresponding description and stock.
+---------+--------------+-----------+---------+
| ararnr | aoarom | totalStock| vovoan |
+---------+--------------+-----------+---------+
| a123456 | description1 | 12 | 2 |
| b123456 | description2 | | 1 |
| 0123456 | description3 | 6 | |
+---------+--------------+-----------+---------+
I'm using sql on db2
SECOND EDIT
The first query will select some article numbers (ararnr) from table ar and find the corresponding description (aoarom) in another table ao.
The second query finds the stock (vovoan and sum ststan) from two differend tables vo and st for the article numbers found in the first query.
The result should have the article number with corresponding description with corresponding stock from vo and st
I can't fully understand what you're asking, but another join may assist you.
example:
SELECT ar.ararnr, ar.ararir, ar.ararom, vo.votgan, SUM(vo.ststan) as totalStock
FROM ar LEFT JOIN ao ON [id=id] LEFT JOIN vo ON [id=id]
Because I can't tell what your tables structure are, or what you're really asking for, this is the best response I can give you.
This also may be what you're looking for:
Combining 2 SQL queries and getting result set in one
You can use this query.
SELECT ar.ararnr, ar.ararir, ar.ararom, vo.votgan, SUM(vo.ststan) as totalStock
FROM ar
LEFT JOIN ao ON ao.ararnr = ar.ararnr
LEFT JOIN vo ON vo.voarnr = ao.ararnr
If you are using SQL Server as database then this can be done with help of OUTER APPLY
SELECT ararnr,aoarom ,temp.totalStock
FROM ar
LEFT JOIN ao ON AR.ARARNR=AO.AOARNR
OUTER APPLY(
SELECT sum(ststan) as totalStock
FROM vo
INNER JOIN st on vo.voarnr=st.starnr
where voarnr = ar.ararnr
)temp
WHERE AR.ARARKD=1389
You'd get a much more complete answer if you were to post the table structure and desired result, but..
You can use the first query as a resultset for your second query, and join to it. something like:
Select
votgan,
sum(ststan) as totalStock
from vo
inner join (Select
ararnr,
ararir,
ararom
from ar
left join ao .....) z on vo.voarnr = z.ararnr
EDIT:
Select
votgan,
sum(ststan) as totalStock,
z.ararnr,
z.aoarom
from vo
inner join (Select
ararnr,
ararir,
ararom
from ar
left join ao .....) z on vo.voarnr = z.ararnr

INNER JOIN Need to use column value twice in results

I've put in the requisite 2+ hours of digging and not getting an answer.
I'd like to merge 3 SQL tables, where Table A and B share a column in common, and Table B and C share a column in common--Tables A and C do not.
For example:
Table A - entity_list
entity_id | entity_name | Other, irrelevant columns
Example:
1 | Microsoft |
2 | Google |
Table B - transaction_history
transaction_id | purchasing_entity | supplying_entity | other, irrelevant columns
Example:
1 | 2 | 1
Table C - transaction_details
transactional_id | amount_of_purchase | Other, irrelevant columns
1 | 5000000 |
Using INNER JOIN, I've been able to get a result where I can link entity_name to either purchasing_entity or supplying_entity. And then, in the results, rather than seeing the entity_id, I get the entity name. But I want to substitute the entity name for both purchasing and supplying entity.
My ideal results would look like this:
1 [transaction ID] | Microsoft | Google | 5000000
The closes I've come is:
1 [transaction ID] | Microsoft | 2 [Supplying Entity] | 5000000
To get there, I've done:
SELECT transaction_history.transaction_id,
entity_list.entity_name,
transaction_history.supplying_entity,
transaction_details.amount_of_purchase
FROM transaction.history
INNER JOIN entity_list
ON transaction_history.purchasing_entity=entity_list.entity.id
INNER JOIN
ON transaction_history.transaction_id=transaction_details.transaction_id
I can't get entity_name to feed to both purchasing_entity and supplying_entity.
Here is the query:
SELECT h.transaction_id, h.purchasing_entity, purchaser.entity_name, h.supplying_entity, supplier.entity_name, d.amount_of_purchase
FROM transaction_history h
INNER JOIN transaction_details d
ON h.transaction_id = d.transaction_id
INNER JOIN entity_list purchaser
ON h.purchasing_entity = purchaser.entity_id
INNER JOIN entity_list supplier
ON h.supplying_entity = supplier.entity_id

join on three tables? Error in phpMyAdmin

I'm trying to use a join on three tables query I found in another post (post #5 here). When I try to use this in the SQL tab of one of my tables in phpMyAdmin, it gives me an error:
#1066 - Not unique table/alias: 'm'
The exact query I'm trying to use is:
select r.*,m.SkuAbbr, v.VoucherNbr from arrc_RedeemActivity r, arrc_Merchant m, arrc_Voucher v
LEFT OUTER JOIN arrc_Merchant m ON (r.MerchantID = m.MerchantID)
LEFT OUTER JOIN arrc_Voucher v ON (r.VoucherID = v.VoucherID)
I'm not entirely certain it will do what I need it to do or that I'm using the right kind of join (my grasp of SQL is pretty limited at this point), but I was hoping to at least see what it produced.
(What I'm trying to do, if anyone cares to assist, is get all columns from arrc_RedeemActivity, plus SkuAbbr from arrc_Merchant where the merchant IDs match in those two tables, plus VoucherNbr from arrc_Voucher where VoucherIDs match in those two tables.)
Edited to add table samples
Table arrc_RedeemActivity
RedeemID | VoucherID | MerchantID | RedeemAmt
----------------------------------------------
1 | 2 | 3 | 25
2 | 6 | 5 | 50
Table arrc_Merchant
MerchantID | SkuAbbr
---------------------
3 | abc
5 | def
Table arrc_Voucher
VoucherID | VoucherNbr
-----------------------
2 | 12345
6 | 23456
So ideally, what I'd like to get back would be:
RedeemID | VoucherID | MerchantID | RedeemAmt | SkuAbbr | VoucherNbr
-----------------------------------------------------------------------
1 | 2 | 3 | 25 | abc | 12345
2 | 2 | 5 | 50 | def | 23456
The problem was you had duplicate table references - which would work, except for that this included table aliasing.
If you want to only see rows where there are supporting records in both tables, use:
SELECT r.*,
m.SkuAbbr,
v.VoucherNbr
FROM arrc_RedeemActivity r
JOIN arrc_Merchant m ON m.merchantid = r.merchantid
JOIN arrc_Voucher v ON v.voucherid = r.voucherid
This will show NULL for the m and v references that don't have a match based on the JOIN criteria:
SELECT r.*,
m.SkuAbbr,
v.VoucherNbr
FROM arrc_RedeemActivity r
LEFT JOIN arrc_Merchant m ON m.merchantid = r.merchantid
LEFT JOIN arrc_Voucher v ON v.voucherid = r.voucherid