How can I join two tables using intervals in Google Big Query?
I have two table:
Table CarsGPS:
ID | Car | Latitude | Longitude
1 | 1 | -22.123 | -43.123
2 | 1 | -22.234 | -43.234
3 | 2 | -22.567 | -43.567
4 | 2 | -22.678 | -43.678
...
Table Areas:
ID | LatitudeMin | LatitudeMax | LongitudeMin | LongitudeMax
1 | -22.124 | -22.120 | -43.124 | -43.120
2 | -22.128 | -22.124 | -43.128 | -43.124
...
I'd like to cross join these tables to check in which areas each car has passed by using Google Big Query.
In a regular SQL server I would make:
SELECT A.ID, C.Car
FROM Cars C, Areas A
WHERE C.Latitude BETWEEN A.LatitudeMin AND A.LatitudeMax AND
C.Longitude BETWEEN A.LongitudeMin AND A.LongitudeMax
But Google Big Query only allows me to do joins (even JOIN EACH) using exact matches among joined tables. And the "FROM X, Y" means UNION, not JOINS.
So, this is not an option:
SELECT A.ID, C.Car
FROM Cars C
JOIN EACH
Areas A
ON C.Latitude BETWEEN A.LatitudeMin AND A.LatitudeMax AND
C.Longitude BETWEEN A.LongitudeMin AND A.LongitudeMax
Then, how can I run something similar to it to identify which cars passed inside each area?
BigQuery now supports CROSS JOIN. Your query would look like:
SELECT A.ID, C.Car
FROM Cars C
CROSS JOIN Areas A
WHERE C.Latitude BETWEEN A.LatitudeMin AND A.LatitudeMax AND
C.Longitude BETWEEN A.LongitudeMin AND A.LongitudeMax
Related
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
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
This should be easy but I'm having a hard time.
I have a many-to-many relationship where, for example, many cars can have many components.
So I want a query to return all cars and the subsequent components used. If no component is used it should just return a NULL value.
Car | Engine | Tyre
----------------------
1 | Engine3 |
2 | Engine4 | Tyre3
3 | Engine1 | Tyre1
But with the following SQL:
SELECT Car.idCar, Engine.idEngine, Tyre.idTyre
FROM ((Component
RIGHT JOIN (Car
LEFT JOIN Car_Component ON Car.idCar = Car_Component.idCar) ON Component.idComponent = Car_Component.idComponent)
LEFT JOIN Engine ON Component.idComponent = Engine.idComponent)
LEFT JOIN Tyre ON Component.idComponent = Tyre.idComponent;
I get:
Car | Engine | Tyre
----------------------
1 | Engine3 |
2 | Engine4 |
2 | | Tyre3
3 | Engine1 |
3 | | Tyre1
I've been searching for a solution for quite some time now and I'm pretty sure I need to make subqueriesm but my knowledge of subqueries is limited and I don't know how to start.
Here is the problem in SQL Fiddle.
Does the following query work for you SQL Fiddle:
SELECT DISTINCT Car.idCar, Engine.idEngine, Tyre.idTyre
FROM (((Car
INNER JOIN Car_Component ON Car.idCar = Car_Component.idCar)
INNER JOIN Component ON Car_Component.idComponent = Component.idComponent)
LEFT JOIN Engine ON Component.idComponent = Engine.idComponent)
LEFT JOIN Tyre ON Component.idComponent = Tyre.idComponent;
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
I am trying to figure out how to use multiple left outer joins to calculate average scores and number of cards. I have the following schema and test data. Each deck has 0 or more scores and 0 or more cards. I need to calculate an average score and card count for each deck. I'm using mysql for convenience, I eventually want this to run on sqlite on an Android phone.
mysql> select * from deck;
+----+-------+
| id | name |
+----+-------+
| 1 | one |
| 2 | two |
| 3 | three |
+----+-------+
mysql> select * from score;
+---------+-------+---------------------+--------+
| scoreId | value | date | deckId |
+---------+-------+---------------------+--------+
| 1 | 6.58 | 2009-10-05 20:54:52 | 1 |
| 2 | 7 | 2009-10-05 20:54:58 | 1 |
| 3 | 4.67 | 2009-10-05 20:55:04 | 1 |
| 4 | 7 | 2009-10-05 20:57:38 | 2 |
| 5 | 7 | 2009-10-05 20:57:41 | 2 |
+---------+-------+---------------------+--------+
mysql> select * from card;
+--------+-------+------+--------+
| cardId | front | back | deckId |
+--------+-------+------+--------+
| 1 | fron | back | 2 |
| 2 | fron | back | 1 |
| 3 | f1 | b2 | 1 |
+--------+-------+------+--------+
I run the following query...
mysql> select deck.name, sum(score.value)/count(score.value) "Ave",
-> count(card.front) "Count"
-> from deck
-> left outer join score on deck.id=score.deckId
-> left outer join card on deck.id=card.deckId
-> group by deck.id;
+-------+-----------------+-------+
| name | Ave | Count |
+-------+-----------------+-------+
| one | 6.0833333333333 | 6 |
| two | 7 | 2 |
| three | NULL | 0 |
+-------+-----------------+-------+
... and I get the right answer for the average, but the wrong answer for the number of cards. Can someone tell me what I am doing wrong before I pull my hair out?
Thanks!
John
It's running what you're asking--it's joining card 2 and 3 to scores 1, 2, and 3--creating a count of 6 (2 * 3). In card 1's case, it joins to scores 4 and 5, creating a count of 2 (1 * 2).
If you just want a count of cards, like you're currently doing, COUNT(Distinct Card.CardId).
select deck.name, coalesce(x.ave,0) as ave, count(card.*) as count -- card.* makes the intent more clear, i.e. to counting card itself, not the field. but do not do count(*), will make the result wrong
from deck
left join -- flatten the average result rows first
(
select deckId,sum(value)/count(*) as ave -- count the number of rows, not count the column name value. intent is more clear
from score
group by deckId
) as x on x.deckId = deck.id
left outer join card on card.deckId = deck.id -- then join the flattened results to cards
group by deck.id, x.ave, deck.name
order by deck.id
[EDIT]
sql has built-in average function, just use this:
select deckId, avg(value) as ave
from score
group by deckId
What's going wrong is that you're creating a Cartesian product between score and card.
Here's how it works: when you join deck to score, you may have multiple rows match. Then each of these multiple rows is joined to all of the matching rows in card. There's no condition preventing that from happening, and the default join behavior when no condition restricts it is to join all rows in one table to all rows in another table.
To see it in action, try this query, without the group by:
select *
from deck
left outer join score on deck.id=score.deckId
left outer join card on deck.id=card.deckId;
You'll see a lot of repeated data in the columns that come from score and card. When you calculate the AVG() over data that has repeats in it, the redundant values magically disappear (as long as the values are repeated uniformly). But when you COUNT() or SUM() them, the totals are way off.
There may be remedies for inadvertent Cartesian products. In your case, you can use COUNT(DISTINCT) to compensate:
select deck.name, avg(score.value) "Ave", count(DISTINCT card.front) "Count"
from deck
left outer join score on deck.id=score.deckId
left outer join card on deck.id=card.deckId
group by deck.id;
This solution doesn't solve all cases of inadvertent Cartesian products. The more general-purpose solution is to break it up into two separate queries:
select deck.name, avg(score.value) "Ave"
from deck
left outer join score on deck.id=score.deckId
group by deck.id;
select deck.name, count(card.front) "Count"
from deck
left outer join card on deck.id=card.deckId
group by deck.id;
Not every task in database programming must be done in a single query. It can even be more efficient (as well as simpler, easier to modify, and less error-prone) to use individual queries when you need multiple statistics.
Using left joins isn't a good approach, in my opinion. Here's a standard SQL query for the result you want.
select
name,
(select avg(value) from score where score.deckId = deck.id) as Ave,
(select count(*) from card where card.deckId = deck.id) as "Count"
from deck;