database table like this
============================
= suburb_id | value
= 1 | 2
= 1 | 3
= 2 | 4
= 3 | 5
query is
SELECT COUNT(suburb_id) AS total, suburb_id
FROM suburbs
where suburb_id IN (1,2,3,4)
GROUP BY suburb_id
however, while I run this query, it doesn't give COUNT(suburb_id) = 0 when suburb_id = 0
because in suburbs table, there is no suburb_id 4, I want this query to return 0 for suburb_id = 4, like
============================
= total | suburb_id
= 2 | 1
= 1 | 2
= 1 | 3
= 0 | 4
A GROUP BY needs rows to work with, so if you have no rows for a certain category, you are not going to get the count. Think of the where clause as limiting down the source rows before they are grouped together. The where clause is not providing a list of categories to group by.
What you could do is write a query to select the categories (suburbs) then do the count in a subquery. (I'm not sure what MySQL's support for this is like)
Something like:
SELECT
s.suburb_id,
(select count(*) from suburb_data d where d.suburb_id = s.suburb_id) as total
FROM
suburb_table s
WHERE
s.suburb_id in (1,2,3,4)
(MSSQL, apologies)
This:
SELECT id, COUNT(suburb_id)
FROM (
SELECT 1 AS id
UNION ALL
SELECT 2 AS id
UNION ALL
SELECT 3 AS id
UNION ALL
SELECT 4 AS id
) ids
LEFT JOIN
suburbs s
ON s.suburb_id = ids.id
GROUP BY
id
or this:
SELECT id,
(
SELECT COUNT(*)
FROM suburb
WHERE suburb_id = id
)
FROM (
SELECT 1 AS id
UNION ALL
SELECT 2 AS id
UNION ALL
SELECT 3 AS id
UNION ALL
SELECT 4 AS id
) ids
This article compares performance of the two approaches:
Aggregates: subqueries vs. GROUP BY
, though it does not matter much in your case, as you are querying only 4 records.
Query:
select case
when total is null then 0
else total
end as total_with_zeroes,
suburb_id
from (SELECT COUNT(suburb_id) AS total, suburb_id
FROM suburbs
where suburb_id IN (1,2,3,4)
GROUP BY suburb_id) as dt
#geofftnz's solution works great if all conditions are simple like in this case. But I just had to solve a similar problem to generate a report where each column in the report is a different query. When you need to combine results from several select statements, then something like this might work.
You may have to programmatically create this query. Using left joins allows the query to return rows even if there are no matches to suburb_id with a given id. If your db supports it (which most do), you can use IFNULL to replace null with 0:
select IFNULL(a.count,0), IFNULL(b.count,0), IFNULL(c.count,0), IFNULL(d.count,0)
from (select count(suburb_id) as count from suburbs where id=1 group by suburb_id) a,
left join (select count(suburb_id) as count from suburbs where id=2 group by suburb_id) b on a.suburb_id=b.suburb_id
left join (select count(suburb_id) as count from suburbs where id=3 group by suburb_id) c on a.suburb_id=c.suburb_id
left join (select count(suburb_id) as count from suburbs where id=4 group by suburb_id) d on a.suburb_id=d.suburb_id;
The nice thing about this is that (if needed) each "left join" can use slightly different (possibly fairly complex) query.
Disclaimer: for large data sets, this type of query might have not perform very well (I don't write enough sql to know without investigating further), but at least it should give useful results ;-)
Related
Let's say i have two tables
Customer
---
Id Name
1 Foo
2 Bar
and
CustomerPurchase
---
CustomerId, Amount, AmountVAT, Accountable(bit)
1 10 11 1
1 20 22 0
2 5 6 0
2 2 3 0
I need a single record for every joined and grouped Customer and CustomerPurchase group.
Every record would contain
columns from table Customer
some aggregation functions like SUM
a 'calculated' column. For example difference of other columns
result of subquery to CustomerPurchase table
An example of result i would like to get
CustomerPurchases
---
Name Total TotalVAT VAT TotalAccountable
Foo 30 33 3 10
Bar 7 9 2 0
I was able to get a single row only by grouping by all the common columns, which i dont think is the right way to do. Plus i have no idea how to do the 'VAT' column and 'TotalAccountable' column, which filters out only certain rows of CustomerPurchase, and then runs some kind of aggregate function on the result. Following example doesn't work ofc but i wanted to show what i would like to achieve
select C.Name,
SUM(CP.Amount) as 'Total',
SUM(CP.AmountVAT) as 'TotalVAT',
diff? as 'VAT',
subquery? as 'TotalAccountable'
from Customer C
inner join CustomerPurchase CR
on C.Id = CR.CustomerId
group by C.Id
I would suggest you just need the follow slight changes to your query. I would also consider for clarity, if you can, to use the terms net and gross which is typical for prices excluding and including VAT.
select c.[Name],
Sum(cp.Amount) as Total,
Sum(cp.AmountVAT) as TotalVAT,
Sum(cp.AmountVAT) - Sum(CP.Amount) as VAT,
Sum(case when cp.Accountable = 1 then cp.Amount end) as TotalAccountable
from Customer c
join CustomerPurchase cp on cp.CustomerId = c.Id
group by c.[Name];
My goal is something like following table:
Key | Count since date X | Count total
1 | 4 | 28
With two simple selects I could gain this values: (the key of the table consists of 3 columns [t$ncmp, t$trav, t$seqn])
1. SELECT COUNT(*) FROM db.table WHERE t$date >= sysdate-2 GROUP BY t$ncmp, t$trav, t$seqn
2. SELECT COUNT(*) FROM db.table GROUP BY t$ncmp, t$trav, t$seqn
How can I join these statements?
What I tried:
SELECT n.t$trav, COUNT(n.t$trav), m.total FROM db.table n
LEFT JOIN (SELECT t$ncmp, t$trav, t$seqn, COUNT(*) as total FROM db.table
GROUP BY t$ncmp, t$trav, t$seqn) m
ON (n.t$ncmp = m.t$ncmp AND n.t$trav = m.t$trav AND n.t$seqn = m.t$seqn)
WHERE n.t$date >= sysdate-2
GROUP BY n.t$ncmp, n.t$trav, n.t$seqn
I tried different variantes, but always got errors like 'group by is missing' or 'unknown qualifier'.
Now this at least executes, but total is always 2.
T$TRAV COUNT(N.T$TRAV) TOTAL
4 2 2
29 3 2
51 1 2
62 2 2
16 1 2
....
If it matter, I will run this as an OPENQUERY from MSSQLSERVER to Oracle-DB.
I'd try
GROUP BY n.t$trav, m.total
You typically GROUP BY the same columns as you SELECT - except those who are arguments to set functions.
My goal is something like following table:
If so, you seem to want conditional aggregation:
select key, count(*) as total,
sum(case when datecol >= date 'xxxx-xx-xx' then 1 else 0 end) as total_since_x
from t
group by key;
I'm not sure how this relates to your sample queries. I simply don't see the relationship between that code and your question.
I have the following table which contains ID's and UserId's.
ID UserID
1111 11
1111 300
1111 51
1122 11
1122 22
1122 3333
1122 45
I'm trying to count the distinct number of 'IDs' so that I get a total, but I also need to get a total of ID's that have also seen the that particular ID as well... To get the ID's, I've had to perform a subquery within another table to get ID's, I then pass this into the main query... Now I just want the results to be displayed as follows.
So I get a Total No for ID and a Total Number for Users ID - Also would like to add another column to get average as well for each ID
TotalID Total_UserID Average
2 7 3.5
If Possible I would also like to get an average as well, but not sure how to calculate that. So I would need to count all the 'UserID's for an ID add them altogether and then find the AVG. (Any Advice on that caluclation would be appreciated.)
Current Query.
SELECT DISTINCT(a.ID)
,COUNT(b.UserID)
FROM a
INNER JOIN b ON someID = someID
WHERE a.ID IN ( SELECT ID FROM c WHERE GROUPID = 9999)
GROUP BY a.ID
Which then Lists all the IDs and COUNT's all the USERID.. I would like a total of both columns. I've tried warpping the query in a
SELECT COUNT(*) FROM (
but this only counts the ID's which is great, but how do I count the USERID column as well
You seem to want this:
SELECT COUNT(DISTINCT a.ID), COUNT(b.UserID),
COUNT(b.UserID) * 1.0 / COUNT(DISTINCT a.ID)
FROM a INNER JOIN
b
ON someID = someID
WHERE a.ID IN ( SELECT ID FROM c WHERE GROUPID = 9999);
Note: DISTINCT is not a function. It applies to the whole row, so it is misleading to put an expression in parentheses after it.
Also, the GROUP BY is unnecessary.
The 1.0 is because SQL Server does integer arithmetic and this is a simple way to convert a number to a decimal form.
You can use
SELECT COUNT(DISTINCT a.ID) ...
to count all distinct values
Read details here
I believe you want this:
select TotalID,
Total_UserID,
sum(Total_UserID+TotalID) as Total,
Total_UserID/TotalID as Average
from (
SELECT (DISTINCT a.ID) as TotalID
,COUNT(b.UserID) as Total_UserID
FROM a
INNER JOIN b ON someID = someID
WHERE a.ID IN ( SELECT ID FROM c WHERE GROUPID = 9999)
) x
I have a table called RESULTS with this structure :
resultid,winner,type
And a table called TICKETS with this structure :
resultid,ticketid,bet,sum_won,status
And I want to show each row from table RESULTS and for each result I want to calculate the totalBet and Sum_won using the values from table TICKETS
I tried to make some joins,some sums,but I cant get what I want.
SELECT *,COALESCE(SUM(tickets.bet),0) AS totalbets,
COALESCE(SUM(tickets.sum_won),0) AS totalwins
FROM `results` NATURAL JOIN `tickets`
WHERE tickets.status<>0
GROUP BY resultid
Please give me some advice.
I want to display something like this
RESULT WINNER TOTALBETS TOTALWINS
1 2 431 222
2 3 0 0
3 1 23 0
4 1 324 111
Use:
SELECT r.*,
COALESCE(x.totalbet, 0) AS totalbet,
COALESCE(x.totalwins, 0) AS totalwins
FROM RESULTS r
LEFT JOIN (SELECT t.resultid,
SUM(t.bet) AS totalbet,
SUM(t.sum_won) AS totalwins
FROM TICKETS t
WHERE t.status != 0
GROUP BY t.resultid) x ON x.resultid = r.resultid
I don't care for the NATURAL JOIN syntax, preferring to be explicit about how to JOIN/link tables together.
SELECT *, COALESCE(SUM(tickets.bet),0) AS totalbets,
COALESCE(SUM(tickets.sum_won),0) AS totalwins
FROM `results` NATURAL JOIN `tickets`
WHERE tickets.status<>0
GROUP BY resultid
Try to replace the first * with resultid. If this helps, then add more columns to SELECT and add them to GROUP BY at the same time.
I have a table in my database:
Name | Element
1 2
1 3
4 2
4 3
4 5
I need to make a query that for a number of arguments will select the value of Name that has on the right side these and only these values.
E.g.:
arguments are 2 and 3, the query should return only 1 and not 4 (because 4 also has 5). For arguments 2,3,5 it should return 4.
My query looks like this:
SELECT name FROM aggregations WHERE (element=2 and name in (select name from aggregations where element=3))
What do i have to add to this query to make it not return 4?
A simple way to do it:
SELECT name
FROM aggregations
WHERE element IN (2,3)
GROUP BY name
HAVING COUNT(element) = 2
If you want to add more, you'll need to change both the IN (2,3) part and the HAVING part:
SELECT name
FROM aggregations
WHERE element IN (2,3,5)
GROUP BY name
HAVING COUNT(element) = 3
A more robust way would be to check for everything that isn't not in your set:
SELECT name
FROM aggregations
WHERE NOT EXISTS (
SELECT DISTINCT a.element
FROM aggregations a
WHERE a.element NOT IN (2,3,5)
AND a.name = aggregations.name
)
GROUP BY name
HAVING COUNT(element) = 3
It's not very efficient, though.
Create a temporary table, fill it with your values and query like this:
SELECT name
FROM (
SELECT DISTINCT name
FROM aggregations
) n
WHERE NOT EXISTS
(
SELECT 1
FROM (
SELECT element
FROM aggregations aii
WHERE aii.name = n.name
) ai
FULL OUTER JOIN
temptable tt
ON tt.element = ai.element
WHERE ai.element IS NULL OR tt.element IS NULL
)
This is more efficient than using COUNT(*), since it will stop checking a name as soon as it finds the first row that doesn't have a match (either in aggregations or in temptable)
This isn't tested, but usually I would do this with a query in my where clause for a small amount of data. Note that this is not efficient for large record counts.
SELECT ag1.Name FROM aggregations ag1
WHERE ag1.Element IN (2,3)
AND 0 = (select COUNT(ag2.Name)
FROM aggregatsions ag2
WHERE ag1.Name = ag2.Name
AND ag2.Element NOT IN (2,3)
)
GROUP BY ag1.name;
This says "Give me all of the names that have the elements I want, but have no records with elements I don't want"