If I do one calculation with one join:
SELECT
SUM(friends_made) as calc1, table2.group_id
FROM
friends_made_table as table1
INNER JOIN
grouped_users as table2 ON table1.user_id = table2.user_id
GROUP BY
table2.group_id
The result I get is:
calc1 | group_id
-----------------
400 | 1
320 | 2
330 | 3
But I also need another calculation (calc2) with the same inner join on table1 but with a different table (table3)
SELECT
SUM(request_accept) AS calc2, table1.group_id
FROM
friends_accept_table AS table3
INNER JOIN
grouped_users as table1 ON table1.user_id = table3.user_id
GROUP BY
table1.group_id
Result is:
calc2 | group_id
-----------------
100 | 1
150 | 2
120 | 3
How can I join these two queries and create a new table showing both of the calculations (calc1, calc2)?
calc1 |calc2 | group_id
-----------------------
400 | 100 | 1
320 | 150. | 2
330 | 120. | 3
EDITED to show tables/results and take out rounding
A join will suffice as long as there is a common set of group_ids across the two results. You may otherwise need a left/right join or full join.
with data1 as (
SELECT SUM(friends_made) as calc1, table2.group_id
FROM friends_made_table as table1 INNER JOIN grouped_users as table2
ON table1.user_id = table2.user_id
GROUP BY table2.group_id
), data2 as (
SELECT SUM(request_accept) as calc2, table1.group_id
FROM friends_accept_table as table3 INNER JOIN grouped_users as table1
ON table1.user_id = table3.user_id
GROUP BY table1.group_id
)
select calc1, calc2, d1.group_id
from data1 d1 inner join data2 d2 on d2.group_id = d1.group_id;
This does assume that your platform supports CTE syntax. If it doesn't there are probably similar rewrites.
Related
Table 1:
| account_no | **other columns**...
+------------+-----------------------
| 1 |
| 2 |
| 3 |
| 4 |
Table 2:
| account_no | TX_No | Balance | History |
+------------+-------+---------+------------+
| 1 | 123 | 123 | 12.01.2011 |
| 1 | 234 | 2312 | 01.03.2011 |
| 3 | 232 | 212 | 19.02.2011 |
| 4 | 117 | 234 | 24.01.2011 |
I have multiple join query, one of the tables(Table 2) inside a query is problematic as it is a view which computes many other things, that is why each query to that table is costly. From Table 2, for each account_no in Table 1 I need the whole row with the greatest TX_NO, this is how I do it:
SELECT * FROM TABLE1 A LEFT JOIN
( SELECT
X.ACCOUNT_NO,
HISTORY,
X.BALANCE
FROM TABLE2 X INNER JOIN
(SELECT
ACCOUNT_NO,
MAX(TX_NO) AS TX_NO
FROM TABLE2
GROUP BY ACCOUNT_NO) Y ON X.ACCOUNT_NO = Y.ACCOUNT_NO) B
ON B.ACCOUNT_NO = A.ACCOUNT_NO
As I understand at first it will make the inner join for all the rows in Table2 and after that left join needed account_no's with Table1 which is what I would like to avoid.
My question: Is there a way to find the max(TX_NO) for only those accounts that are in Table1 instead of going through all? I think it will help to increase the speed of the query.
I think you are on the right track, but I don't think that you need to, and would not myself, nest the subqueries the way you have done. Instead, if you want to get each record from table 1 and the matching max record from table 2, you can try the following:
SELECT * FROM TABLE1 t1
LEFT JOIN
(
SELECT t.*,
ROW_NUMBER() OVER (PARTITION BY account_no ORDER BY TX_No DESC) rn
FROM TABLE2 t
) t2
ON t1.account_no = t2.account_no AND
t2.rn = 1
If you want to continue with your original approach, this is how I would do it:
SELECT *
FROM TABLE1 t1
LEFT JOIN TABLE2 t2
ON t1.account_no = t2.account_no
INNER JOIN
(
SELECT account_no, MAX(TX_No) AS max_tx_no
FROM TABLE2
GROUP BY account_no
) t3
ON t2.account_no = t3.account_no AND
t2.TX_No = t3.max_tx_no
Instead of using a window function to find the greatest record per account in TABLE2, we use a second join to a subquery instead. I would expect the window function approach to perform better than this double join approach, and once you get used to it can even easier to read.
If table1 is comparatiely less expensive then you could think of doing a left outer join first which would considerable decrease the resultset and from that pick the latest transaction id records alone
select <required columns> from
(
select f.<required_columns),row_number() over (partition by account_no order by tx_id desc ) as rn
from
(
a.*,b.tx_id,b.balance,b.History
from table1 a left outer join table2 b
on a.account_no=b.account_no
)f
)g where g.rn=1
I'd like to do a MINUS operation between two tables like these:
table1:
employee_id | job | sector
----------- | ------ | ------
10 | a | 1
10 | a | 2
10 | b | 4
table2:
job | sector
---- | ------
a | 1
a | 2
a | 3
b | 1
b | 4
c | 1
c | 2
and as result I want, for every employee_id, the {job,sector} not connected in table1.
RESULT:
employee_id | job | sector
----------- | --- | ------
10 | a | 3
10 | b | 1
10 | c | 1
10 | c | 2
Is it possible?
I hope I have written in a clear way! Thanks!
First select the complete data set, i.e. employee_id X job/sector. From these remove the existing table1 entries to get the lacking ones. (I've renamed your table table2 to job_sector for readability. I also suppose you have an employee table.)
select e.employee_id, js.job, js.sector
from employee e
cross join job_sector js
minus
select employee_id, job, sector
from table1;
Left join, where t2 is null
select t1.*
from table1 t1
let join table2 t2
on t1.job = t2.job
and t1.sector = t2.sector
where t2.job is null
This sounds like just a left join (or not in or not exists):
select 10 as employee_id, t2.*
from table2 t2 left join
table1 t1
on t2.job = t1.job and t2.sector = t1.sector
where t1.job is null;
I am a bit confused on how you get the employee id if the tables are not linked.
If you have multiple employees in t1, then you can do:
select e.employee_id, t2.*
from (select distinct employee_id from t1) e cross join
table2 t2 left join
table1 t1
on t2.job = t1.job and t2.sector = t1.sector and
e.employee_id = t1.employee_id
where t1.job is null;
You can simply achieve it by doing a left join. You query will look something like this:
SELECT T2.*
FROM TABLE2 T2 LEFT JOIN
TABLE1 T1
ON T2.JOB = T1.JOB AND T2.SECTOR = T2.SECTOR
WHERE T1.JOB IS NULL;
Though table must be linked in order to get the employee id.
I am trying to join two tables one is a unique feature the seconds is readings taken on several dates that relate to the unique features. I want all of the records in the first table plus the most recent reading. I was able to get the results I was looking for before adding the shape field. By using the code
SELECT
Table1.Name, Table1.ID, Table1.Shape,
Max(Table2.DATE) as Date
FROM
Table1
LEFT OUTER JOIN
Table2 ON Table1.ID = table2.ID
GROUP BY
Table1.Name, Table1.ID, Table1.Shape
The shape field is a geometry type and I get the error
'The type "Geometry" is not comparable. It can not be use in the Group By Clause'
So I need to go about it a different way, but not sure how.
Below is a sample of the two tables and the desired results.
Table1
Name| ID |Shape
AA1 | 1 | X
BA2 | 2 | Y
CA1 | 3 | Z
CA2 | 4 | Q
Table2
ID | Date
1 | 5/27/2013
1 | 6/27/2014
2 | 5/27/2013
2 | 6/27/2014
3 | 5/27/2013
3 | 6/27/2014
My Desired Result is
Name| ID |Shape |Date
AA1 | 1 | X | 6/27/2014
BA2 | 2 | Y | 6/27/2014
CA1 | 3 | Z | 6/27/2014
CA2 | 4 | Q | Null
You can do the aggregation on Table2 in a CTE, finding the MAX(DATE) for each ID, and then join that result to Table1:
WITH AggregatedTable2(ID, MaxDate) AS
(
SELECT
ID, MAX(DATE)
FROM
Table2
GROUP BY
ID
)
SELECT
t1.ID, t1.Name, t1.Shape, t2.MaxDate
FROM
Table1 t1
LEFT JOIN
AggregatedTable2 t2 ON t1.ID = t2.ID
Try casting geometry as a varchar.
Select Table1.Name, Table1.ID, cast(Table1.Shape as varchar(1)) AS Shape, Max(Table2.DATE) as Date
FROM Table1 LEFT OUTER JOIN
Table2 ON Table1.ID = table2.ID
Group By Table1.Name, Table1.ID, cast(Table1.Shape as varchar(1))
Try this:
SELECT t1.Name
, t1.ID
, t1.Shape
, MAX(t2.Date) As Date
FROM Table1 AS t1
LEFT JOIN Table2 AS t2
ON t2.ID = t1.ID
GROUP
BY t1.Name
, t1.ID
, t1.Shape
Firstly, I apologize for my English. I want get auctions with count of bids and buys. It should look like this:
id | name | bids | buys
-----------------------
1 | Foo | 4 | 1
2 | Bar | 0 | 0
I have tables like following:
auction:
id | name
---------
1 | Foo
2 | Bar
auction_bid:
id | auction_id
---------------
1 | 1
2 | 1
3 | 1
4 | 1
auction_buy:
id | auction_id
---------------
1 | 1
I can get numbers in two queries:
SELECT *, COUNT(abid.id) AS `bids` FROM `auction` `t` LEFT JOIN auction_bid abid ON (t.id = abid.auction) GROUP BY t.id
SELECT *, COUNT(abuy.id) AS `buys` FROM `auction` `t` LEFT JOIN auction_buy abuy ON (t.id = abuy.auction) GROUP BY t.id
But when i combined it into one:
SELECT *, COUNT(abid.id) AS `bids`, COUNT(abuy.id) AS `buys` FROM `auction` `t` LEFT JOIN auction_bid abid ON (t.id = abid.auction) LEFT JOIN auction_buy abuy ON (t.id = abuy.auction) GROUP BY t.id
It was returning wrong amount (bids as much as buys).
How to fix this and get counts in one query?
You'll need to count DISTINCT abuy and abid IDs to eliminate the duplicates;
SELECT t.id, t.name,
COUNT(DISTINCT abid.id) `bids`,
COUNT(DISTINCT abuy.id) `buys`
FROM `auction` `t`
LEFT JOIN auction_bid abid ON t.id = abid.auction_id
LEFT JOIN auction_buy abuy ON t.id = abuy.auction_id
GROUP BY t.id, t.name;
An SQLfiddle to test with.
Try this:
SELECT t.*,COUNT(abid.id) as bids,buys
FROM auction t LEFT JOIN
auction_bid abid ON t.id = abid.auction_id LEFT JOIN
(SELECT t.id, Count(abuy.id) as buys
FROM auction t LEFT JOIN
auction_buy abuy ON t.id = abuy.auction_id
GROUP BY t.id) Temp ON t.id=Temp.id
GROUP BY t.id
Result:
ID NAME BIDS BUYS
1 Foo 2 0
2 Bar 1 1
Result in SQL Fiddle.
Table 1:
TicketNumber | Rules
---------------------------
PR123 | rule_123
PR123 | rule_234
PR123 | rule_456
PR999 | rule_abc
PR999 | rule_xyz
Table2:
TicketNumber | Rules
---------------------------
PR123 | rule_123
PR123 | rule_234
PR999 | rule_abc
NOTE: Both tables have the same structure: same column names but different count.
NOTE: Both tables have same set of TicketNumber values
CASE 1:
If I need ticket and rules count of each ticket from table1, the query is:
Select [TicketNo], COUNT([TicketNo]) AS Rules_Count from [Table1] group by TicketNo
This will give me output in format :
ticketNumber | Rules_Count
---------------------------
PR123 | 3
PR999 | 9
CASE 2: (NEED HELP WITH THIS)
Now, the previous query gets the ticket and the count of the ticket of only 1 table. I need the count of the same ticket (since both have same set of tkt nos) in table2 also.
I need result in this way:
ticketNumber | Count(ticketNumber) of table1 | Count(ticketNumber) of table2
---------------------------------------------------------------------------------
PR123 | 3 | 2
PR999 | 2 | 1
Both Table1 and table2 have the same set of ticket nos but different counts
How do i get the result as shown above?
A simpler solution from a "statement point of view" (without COALESCE that maybe it's not so easy to understand).
Pay attention to the performances:
Select T1.TicketNumber,T1.Rules_Count_1,T2.Rules_Count_2
FROM
(
Select [TicketNumber], COUNT([TicketNumber]) AS Rules_Count_1
from [Table1] T1
group by TicketNumber) T1
INNER JOIN
(
Select [TicketNumber], COUNT([TicketNumber]) AS Rules_Count_2
from [Table2] T2
group by TicketNumber
) T2
on T1.TicketNumber = T2.TicketNumber
SQL Fiddle Demo
You can do this with a full outer join after aggregation (or an inner join if you really know that both tables have the same tickets:
select coalesce(t1.TicketNo, t2.TicketNo) as TicketNo,
coalesce(t1.Rules_Count, 0) as t1_Rules_Count,
coalesce(t2.Rules_Count, 0) as t2_Rules_Count
from (Select [TicketNo], COUNT([TicketNo]) AS Rules_Count
from [Table1]
group by TicketNo
) t1 full outer join
(Select [TicketNo], COUNT([TicketNo]) AS Rules_Count
from [Table2]
group by TicketNo
) t2
on t1.TicketNo = t2.TicketNo;
SELECT A.center,
A.total_1st,
B.total_2nd
FROM (SELECT a.center,
Count (a.dose1) AS Total_1st
FROM table_1 a
GROUP BY a.center) A
INNER JOIN (SELECT b.center,
Count (b.dose2) AS Total_2nd
FROM table_2 b
GROUP BY b.center) B
ON a.center = b.center
ORDER BY A.center