Thank you Stack-Community,
This is probably obvious for most of you but I just don't understand why it doesn't work.
I am using the Northwind database and lets say I am trying to find the countries that or not occurring twice but are listed either more than twice or less often.
I already figured out other ways of doing it with a having statement, so I am not looking for alternatives but trying to understand why my initial attempt is not working.
I look at it and look at it and it makes perfect sense to me. Can someone explain what's the problem?
SELECT country, count(country)
FROM Customers
WHERE 2 not in (SELECT count(country) FROM Customers GROUP BY country)
GROUP BY country
;
You need correlated subquery:
SELECT country, count(country)
FROM Customers c
WHERE 2 not in (SELECT count(country) FROM Customers c2
WHERE c2.country = c.country )
GROUP BY country;
Otherwise you get something like:
SELECT country, count(country)
FROM Customers c
WHERE 2 not in (1,2,3) -- false in every case and empty resultset
GROUP BY country;
Imagine that you have:
1, 'UK' -- 1
2, 'DE' -- 2
3, 'DE'
4, 'RU' -- 1
Now you will get equivalent of
SELECT country, count(country)
FROM Customers c
WHERE 2 not in (1,2,1) -- false in every case and empty resultset
GROUP BY country;
-- 0 rows selected
Related
I have to write a report by doing some SQL in MS SQL server. The data I have is like this:
UserID,Country, CommNumber
00001, IN, 1001
00002, IN, NULL
00003, US, 1002
00004, US, 1003
00005, DE, NULL
00006, DE, NULL
00007, US, NULL
Now I want to pull up the list of countries where all CommNumbers are NULL. Even if one user has a CommNumber in that country, I don't want that country to be in list. So looking at above only DE has all two users with NULL on CommNumber. US and IN have atleast one user where the CommNumber is not NULL.
Hope this question makes sense.
My attempt is:
SELECT
[COUNTRY]
,COUNT(*) AS 'COMMNUMBER_USERS'
FROM
<TABLENAME>
WHERE [COMMNUMBER] IS NULL
GROUP BY [C]
ORDER BY [COMMNUMBER_USERS]
The above is not giving me the correct results. I understand why because I don't have way to tell it that I only want countries where all commnumbers are null.
I would use NOT EXISTS :
SELECT t.*
FROM table t
WHERE NOT EXISTS (SELECT 1 FROM table t1 WHERE t1.Country = t.Country AND t1.CommNumber IS NOT NULL);
If you want only Country then you can do aggregation :
select country
from table t
group by country
having max(commnumber) is null;
You can simply use group by and having:
select country
from t
group by country
having max(commnumber) is null;
You can try using correlated subquery
select * from tablename a where not exists
(select 1 from tablename b where a.country=b.country and b.commnumber is not null)
SELECT Country
FROM Tablename
GROUP BY Country
HAVING sum(ISNULL(Commnumber, 0)) = 0
You can use this one as well
I am working on a SQL assignment in Oracle. There are two tables.
table1 is called Person10:
fields include: ID, Fname, Lname, State, DOH, JobTitle, Salary, Cat.
table2 is called StateInfo:
fields include: State, Statename, Capital, Nickname, Pop2010, pop2000, pop1990, sqmiles.
Question:
Create a view named A10T2 that will display the StateName, Capital and Nickname of the states that have at least 25 people in the Person10 table with a Cat value of N and an annual salary between $75,000 and $125,000. The three column headings should be StateName, Capital and Nickname. The rows should be sorted by the name of the state.
What I have :
CREATE VIEW A10T2 AS
SELECT StateName, Capital, Nickname
FROM STATEINFO INNER JOIN PERSON10 ON
STATEINFO.STATE = PERSON10.STATE
WHERE Person10.CAT = 'N' AND
Person10.Salary in BETWEEN (75000 AND 125000) AND
count(Person10.CAT) >= 25
ORDER BY STATE;
It gives me an error saying missing expression. I may need a group expression... but i dont know what I am doing wrong.
Yeah I originally messed this up when I first answered this because it was on the fly and I didn't have a chance to test what I was putting down. I forgot using a GROUP BY is more suited for aggregate functions (Like SUM, AVG and COUNT in the select) and that's probably why it's throwing the error. Using a ORDER BY is probably the correct option in this case. And you want to order your results by the state so you would use StateName.
SELECT S.StateName, S.Capital, S.Nickname
FROM STATEINFO S
INNER JOIN PERSON10 P ON S.STATE = P.STATE
WHERE P.CAT = 'N'
AND P.Salary BETWEEN 75000 AND 125000
ORDER BY S.StateName
HAVING count(P.CAT) >= 25;
Try moving your count() to HAVING instead of WHERE. You'll also need a GROUP BY clause containing StateName, Capital, and Nickname.
I know this link is Microsoft, not Oracle, but it should be helpful.
https://msdn.microsoft.com/en-us/library/ms180199.aspx?f=255&MSPPError=-2147217396
I'm no Oracle expert, but I'm pretty sure
Person10.Salary in BETWEEN (75000 AND 125000)
should be
Person10.Salary BETWEEN 75000 AND 125000
(no IN and no parentheses). That's how all other SQL dialects I know of work.
Also, move the COUNT() from the WHERE clause to a HAVING clause:
CREATE VIEW A10T2 AS
SELECT StateName, Capital, Nickname
FROM STATEINFO INNER JOIN PERSON10 ON
STATEINFO.STATE = PERSON10.STATE
WHERE Person10.CAT = 'N' AND
Person10.Salary BETWEEN 75000 AND 125000
ORDER BY STATE
HAVING count(Person10.CAT) >= 25;
You can try using a Sub Query like this.
CREATE VIEW A10T2 AS
SELECT statename, capital, nickname
FROM stateinfo
WHERE statename IN (SELECT statename
FROM person10
WHERE Cat = 'N'
AND Salary BETWEEN 75000 AND 125000
GROUP BY statename
HAVING COUNT(*) >= 25)
ORDER BY statename
I have a table Sales with columns SalesID, SalesName, SalesCity, SalesState.
I am trying to come up with a query that only shows salesName where there is one SalesName per SalesCity. So for example, if SaleA is in Houston and SaleB is in Houston, SaleA and SaleB will not be returned.
select
SalesName, SalesCity, SalesState
from
Sales
where
(select count(*) from Sales group by SalesCity) = 1;
I am not entirely sure how to link the inner select back out. I need another column in the nested select to identify the SalesID. I am currently stuck and have made no progress.
You can get the names of cities that have only 1 sale by using GROUP BY and HAVING operators. Then use these results in your where clause:
SELECT SalesName, SalesCity, SalesState
FROM Sales WHERE SalesCity IN
(
SELECT SalesCity
FROM Sales
GROUP BY SalesCity
HAVING COUNT(SalesCity) = 1
)
You can do this without a subquery:
select MIN(SalesName) as SalesName, SalesCity, MIN(SalesState) as SalesState
from Sales
group by SalesCity
having count(*) = 1;
If there is only one row for the city, then the min() will return the value on that row.
I am having a real problem trying to get a query with the data I need. I have tried a few methods without success. I can get the data with 4 separate queries, just can't get hem into 1 query. All data comes from 1 table. I will list as much info as I can.
My data looks like this. I have a customerID and 3 columns that record who has worked on the record for that customer as well as the assigned acct manager
RecID_Customer___CreatedBy____LastUser____AcctMan
1-------1374----------Bob Jones--------Mary Willis------Bob Jones
2-------1375----------Mary Willis------Bob Jones--------Bob Jones
3-------1376----------Jay Scott--------Mary Willis-------Mary Willis
4-------1377----------Jay Scott--------Mary Willis------Jay Scott
5-------1378----------Bob Jones--------Jay Scott--------Jay Scott
I want the query to return the following data. See below for a description of how each is obtained.
Employee___Created__Modified__Mod Own__Created Own
Bob Jones--------2-----------1---------------1----------------1
Mary Willis------1-----------2---------------1----------------0
Jay Scott--------2-----------1---------------1----------------1
Created = Counts the number of records created by each Employee
Modified = Number of records where the Employee is listed as Last User
(except where they created the record)
Mod Own = Number of records for each where the LastUser = Acctman
(account manager)
Created Own = Number of Records created by the employee where they are
the account manager for that customer
I can get each of these from a query, just need to somehow combine them:
Select CreatedBy, COUNT(CreatedBy) as Created
FROM [dbo].[Cust_REc] GROUP By CreatedBy
Select LastUser, COUNT(LastUser) as Modified
FROM [dbo].[Cust_REc] Where LastUser != CreatedBy GROUP By LastUser
Select AcctMan, COUNT(AcctMan) as CreatePort
FROM [dbo].[Cust_REc] Where AcctMan = CreatedBy GROUP By AcctMan
Select AcctMan, COUNT(AcctMan) as ModPort
FROM [dbo].[Cust_REc] Where AcctMan = LastUser AND NOT AcctMan = CreatedBy GROUP By AcctMan
Can someone see a way to do this? I may have to join the table to itself, but my attempts have not given me the correct data.
The following will give you the results you're looking for.
select
e.employee,
create_count=(select count(*) from customers c where c.createdby=e.employee),
mod_count=(select count(*) from customers c where c.lastmodifiedby=e.employee),
create_own_count=(select count(*) from customers c where c.createdby=e.employee and c.acctman=e.employee),
mod_own_count=(select count(*) from customers c where c.lastmodifiedby=e.employee and c.acctman=e.employee)
from (
select employee=createdby from customers
union
select employee=lastmodifiedby from customers
union
select employee=acctman from customers
) e
Note: there are other approaches that are more efficient than this but potentially far more complex as well. Specifically, I would bet there is a master Employee table somewhere that would prevent you from having to do the inline view just to get the list of names.
this seems pretty straight forward. Try this:
select a.employee,b.created,c.modified ....
from (select distinct created_by from data) as a
inner join
(select created_by,count(*) as created from data group by created_by) as b
on a.employee = b.created_by)
inner join ....
This highly inefficient query may be a rough start to what you are looking for. Once you validate the data then there are things you can do to tidy it up and make it more efficient.
Also, I don't think you need the DISTINCT on the UNION part because the UNION will return DISTINCT values unless UNION ALL is specified.
SELECT
Employees.EmployeeID,
Created =(SELECT COUNT(*) FROM Cust_REc WHERE Cust_REc.CreatedBy=Employees.EmployeeID),
Mopdified =(SELECT COUNT(*) FROM Cust_REc WHERE Cust_REc.LastUser=Employees.EmployeeID AND Cust_REc.CreateBy<>Employees.EmployeeID),
ModOwn =
CASE WHEN NOT Empoyees.IsManager THEN NULL ELSE
(SELECT COUNT(*) FROM Cust_REc WHERE AcctMan=Employees.EmployeeID)
END,
CreatedOwn=(SELECT COUNT(*) FROM Cust_REc WHERE AcctMan=Employees.EmployeeID AND CReatedBy=Employees.EMployeeID)
FROM
(
SELECT
EmployeeID,
IsManager=CASE WHEN EXISTS(SELECT AcctMan FROM CustRec WHERE AcctMan=EmployeeID)
FROM
(
SELECT DISTINCT
EmployeeID
FROM
(
SELECT EmployeeID=CreatedBy FROM Cust_Rec
UNION
SELECT EmployeeID=LastUser FROM Cust_Rec
UNION
SELECT EmployeeID=AcctMan FROM Cust_Rec
)AS Z
)AS Y
)
AS Employees
I had the same issue with the Modified column. All the other columns worked okay. DCR example would work well with the join on an employees table if you have it.
SELECT CreatedBy AS [Employee],
COUNT(CreatedBy) AS [Created],
--Couldn't get modified to pull the right results
SUM(CASE WHEN LastUser = AcctMan THEN 1 ELSE 0 END) [Mod Own],
SUM(CASE WHEN CreatedBy = AcctMan THEN 1 ELSE 0 END) [Created Own]
FROM Cust_Rec
GROUP BY CreatedBy
I have got a table of orders placed by customer , what i want is to check from which part of the country orders are coming historically, I can only check this by postcodes , for intance an order with post code SK... means its stockport , similarly the post code starting from M .. means the order is from manchester, Is it possible to write a query which can count the orders by postcode.
Some of the fields of the Order table:
OrderNumber OGUID custID firstname last name address postcode email authorisation date etc...
Any suggestion or assistance will be appreciated.
Thanks
Here is way that works... but it can get too long for a huge list. I will try to find a way around that problem.
SELECT
CASE
WHEN postcode LIKE 'SK%' THEN 'SK'
WHEN postcode LIKE 'M%' THEN 'M'
END AS group_by_value
, COUNT(*) AS group_by_count
FROM [Table] a
GROUP BY
CASE
WHEN postcode LIKE 'SK%' THEN 'SK'
WHEN postcode LIKE 'M%' THEN 'M'
END
If you have a table that contains the city code and city name, then you might be able to use something like the following which joins your orders table to the codes using a LIKE:
select o.postcode,
c.city,
count(c.code) over(partition by c.code) Total
from orders o
inner join codes c
on o.postcode like '%'+c.code+'%'
See SQL Fiddle with Demo
You can use GROUP BY to get the total number of orders in each postcode:
select postcode, count(postcode) TotalOrdersByPostCode
from orders
group by postcode
If you want the City included, then you can also GROUP BY city:
select city, postcode, count(postcode) TotalOrdersByPostCode
from orders
group by city, postcode
select count(1) over(partition by postcode) as countByPostcode, othecolumnhere
from Order
Have you tried something like this? The town part of the postcode will be the first 1 or 2 bytes, delimited by a number after, I think. So this will give you the first few letters.
select substring(postcode,1, patindex('%[0-9]%',postcode)-1), count(*)
from Order
group by substring(postcode,1, patindex('%[0-9]%',postcode)-1)
Then you'll have to decode M into Manchester, W into West London, GU into Guildford etc...