I am trying to create some SQL that will count the number of employees within each company and return only those companies with greater than or equal to n employees.
I have the following tables (simplified):
CompanyEmployee Table
ID Name IsCompany
1 John Joe 0
2 Company Y 1
3 Company X 1
4 Sally Jeff 0
5 James Peach 0
Employment Table
ID EmployeeID CompanyID
1 1 2
2 4 3
3 5 3
My desired result for n=2:
ID Name IsCompany
3 Company X 1
I have the following SQL:
SELECT t.* FROM CompanyEmployee AS t
WHERE t.ID IN (
SELECT DISTINCT (t.ID)
FROM CompanyEmployee AS t
INNER JOIN Employment AS t0 ON t.ID = t0.CompanyID
WHERE t.IsCompany = 1
GROUP BY t0.CompanyID
HAVING COUNT(t0.EmployeeID) >= n)
But it generates the following error:
Column 'CompanyEmployee.ID' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.
Any help or advice would be greatly appreciated!
Mixing companies and employees this way is a bad idea. Using a straight inner join may work as long as the id values between the two different types of rows never intersect. I guess if it's an identity column then that's not supposed to happen.
with Companies as (
select ID as CompanyID, Name
from CompanyEmployee
where IsCompany = 1
), Employees as (
select CompanyID, Name
from CompanyEmployee where
IsCompany = 0
)
select c.CompanyID, Name, 1 as IsCompany
from
Companies as c
inner join Employment as ec on ec.CompanyID = c.CompanyID
inner join Employees as e on e.EmployeeID = ce.EmployeeID
group by
c.CompanyID
having count(*) >= n
There is still a straightforward way to do it:
select *
from CompanyEmployee
where ID in (
select CompanyID
from Employment
group by CompanyID
having count(*) >= n)
)
Try this:
SELECT t1.CompanyId, t2.CompanyName, COUNT(t1.CompanyId)
FROM Employment AS t1 INNER JOIN CompanyEmployee AS t2 ON t1.CompanyId = t2.Id
GROUP BY t1.CompanyId, t2.CompanyName
HAVING COUNT(t1.CompanyId)>=n
where n is a number of employees...
Related
I have below 3 tables and I want to write a SQL query which will list the store present in all city: (here the result should be "Walmart")
Stores:
ID Name
1 Walmart
2 Target
3 Sears
Stores_City
ID Store_id City ID
1 1 10
2 1 20
3 2 10
4 1 30
City
ID Name
10 NewYork
20 Boston
30 Eagan
I am unable to find a query that works. Any help is appreciated!
select s.Name
from Stores s
inner join
(
select store_id, count(distinct city_id)
from stores_city
group by store_id
having count(distinct city_id) = (select count(*) from City)
) x
on x.store_id = s.id;
You can do it by grouping on store_id and checking for the count from stores table.
A straight join would work
Select distinct s.name from stores s inner join store _city SC on s.id=sc.id
Inner join city c on
Sc.city_id = c.id
Here is another way that will work:
select s.*
from stores s
where not exists (
select c.id
from city c
except
select sc.city_id
from stores_city sc
where sc.store_id = s.id
)
Try this:
SELECT
s.Name
FROM Stores s
WHERE NOT EXISTS (SELECT TOP 1
1
FROM City c
LEFT JOIN Stores_City sc
ON c.ID = sc.CityID
AND sc.Store_id = s.ID
WHERE sc.ID IS NULL)
1:Table COUNTRY
ID NAME
1 USA
2 BRITAIN
2:Table PEOPLE
P_ID P_NAME
4 JOHN
5 MONTY
Resultant table should have
ID NAME P_ID P_NAME
1 USA 4 JOHN
2 BRITAIN 5 MONTY
Just side by side merge. Is it possible? LIKE TABLE1 | TABLE2
Example
with x as (
select id, name, rownum rn from country
order by id),
y as(
select p_id, p_name, rownum rn from people
order by p_id)
select id,name,p_id,p_name from x
left join y on y.rn = x.rn
union
select id,name,p_id,p_name from y
left join x on y.rn = x.rn
If I well understood your question this could work:
SELECT *
FROM (SELECT T1.*,ROWNUM AS R FROM COUNTRY T1) V1,
(SELECT T2.*,ROWNUM AS R FROM PEOPLE T2) V2
WHERE V1.R = V2.R(+)
But you need to know wich table is bigger and I fear you aren't going to to get reliable results
This should work..
select c.id,c.name, p.p_id, p.p_name from country c inner join people p on c.id = p.p_id;
Try this:
SELECT * FROM COUNTRY C
INNER JOIN PEOPLE P ON C.ID = P.P_ID;
Updated answer :
Select * from #country as c , #people as p where p_id =4 and id=1 OR id = 2 and p_id=5
I need to select only the most significant value from a table. Using Postgre SQL (last version) Follows the data sample:
Table Company
Id, Name, ExternalId, StartAt
1 Comp1 54123 21/05/2000
2 Comp2 23123 21/05/2000
Table Address
Id, Company, Address_Type, City
1 1 7 A
2 2 2 B
3 2 62 C
Table Adress_Type
Id, Name, importance_order
62 Adt1 1
7 Adt2 2
2 Adt3 2
What i need to do is to get the company and its major Address, based on the "importance_order". There is already a function that returns this result:
Create function~~~~
Select * from Company c
join Address a on c.address_id = a.id
Join AddressType at on a.adresstype_id = at.id
ORDER by at.importance_order
Limit 1
My problem now is that this function is called one time for every row in the query, and it take so much time (about 20 min.). Should it be possible to do this similar aproach by joinning tables? I need this join to get the First "most important"address, and then get the City name, but need to do this in a "faster" way. I need to reduce subquery`s number to its minimal.
Select * from table t
inner join Company c on t.company_id = c.id
left join address a on (c.company_id = c.id)
left join addresstype at on (a.adresstype_id = at.id)
where at.id = (
select max(id) from addresstype
where adresstype in (
select adresstype from adress where company_id = c.id
)
)
If it is not clear tell me that i get more into details.
Thanks.
For this you need PostgreSQL 8.4+ I suppose
SELECT T.*
FROM TABLE AS T
INNER JOIN
(
SELECT * FROM
(
SELECT C1.*, ROW_NUMBER() OVER(partition by C1.ID ORDER BY T.IMPORTANCE_ORDER) AS RN
FROM COMPANY AS C1
INNER JOIN ADDRESS AS A
ON C1.ID = A.COMPANY
INNER JOIN ADDRESS_TYPE AS T
ON T.ID = A.ADDRESS_TYPE_ID
) A
WHERE RN = 1
) AS B
ON B.ID= T.COMPANY_ID
This SQL:
select Name,
(select COUNT(1) from tbl_projects where statusId = tbl_sections.StatusId) as N
from tbl_sections
left join tbl_section_names on tbl_section_names.Id = NameId
Generates the follows data:
Name N
Completed 133
Cancelled 100
Unassigned 1
Sales 49
Development 10
Development 4
Development 1
I'm trying to modify it so it returns the data as follows:
Name N
Completed 133
Cancelled 100
Unassigned 1
Sales 49
Development 15
(ie, sum up the rows where the name is the same)
Can anyone suggest some clues on how to make this work ? I'm guessing I need a SUM and a GROUP BY, but it never even runs the query as all I get are errors.
Try this query. It sums N grouped by Name.
SELECT Name, SUM(N)
FROM (
SELECT Name,
(SELECT COUNT(1)
FROM tbl_projects
WHERE statusId = tbl_sections.StatusId
) AS N
FROM tbl_sections
LEFT JOIN tbl_section_names ON tbl_section_names.Id = NameId
) a
GROUP BY a.Name
Try this
select Name, count(p.statusid) N
from tbl_sections
left join tbl_section_names on tbl_section_names.Id = NameId
left outer join tbl_projects p on tbl_sections.StatusId = p.statusId
group by Name
Select Name, Sum(N) from
(select Name,
(select COUNT(1) from tbl_projects where statusId = tbl_sections.StatusId) as N
from tbl_sections
left join tbl_section_names on tbl_section_names.Id = NameId)
group by Name
This query is giving you count per status, which means Development has sections with three different status's, and the query would reflect this and make more sense if you added the status as a column:
select Name, tbl_sections.StatusId,
(select COUNT(1) from tbl_projects where statusId = tbl_sections.StatusId) as N
from tbl_sections
left join tbl_section_names on tbl_section_names.Id = NameId
I don't know the structure of your database, but I if you want a count of the number of sections per name, might be like this. This basically will look at the result of the join, and then summarize it by telling you the number of times each unique name occurs:
select Name, count(*)
from tbl_sections
left join tbl_section_names on tbl_section_names.Id = NameId
Group By Name
Try and give this a go.
select Name,
SUM(select COUNT(1) from tbl_projects where statusId = tbl_sections.StatusId) as N
from tbl_sections
left join tbl_section_names on tbl_section_names.Id = NameId
group by Name
I am having trouble writing a query that will select all Skills, joining the Employee and Competency records, but only return one skill per employee, their newest Skill. Using this sample dataset
Skills
======
id employee_id competency_id created
1 1 1 Jan 1
2 2 2 Jan 1
3 1 2 Jan 3
Employees
===========
id first_name last_name
1 Mike Jones
2 Steve Smith
Competencies
============
id title
1 Problem Solving
2 Compassion
I would like to retrieve the following data
Skill.id Skill.employee_id Skill.competency_id Skill.created Employee.id Employee.first_name Employee.last_name Competency.id Competency.title
2 2 2 Jan 1 2 Steve Smith 2 Compassion
3 1 2 Jan 3 1 Mike Jones 2 Compassion
I was able to select the employee_id and max created using
SELECT MAX(created) as created, employee_id FROM skills GROUP BY employee_id
But when I start to add more fields in the select statement or add in a join I get the 'Column 'xyz' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.' error.
Any help is appreciated and I don't have to use GROUP BY, it's just what I'm familiar with.
The error that you were getting is because SQL Server requires any item in the SELECT list to be included in the GROUP BY if there is an aggregate function being used.
The problem with that is you might have unique values in some columns which can throw off the result. So you will want to rewrite the query to use one of the following:
You can use a subquery to get this result. This gets the max(created) in a subquery and then you use that result to get the correct employee record:
select s.id SkillId,
s.employee_id,
s.competency_id,
s.created,
e.id employee,
e.first_name,
e.last_name,
c.id competency,
c.title
from Employees e
left join Skills s
on e.id = s.employee_id
inner join
(
SELECT MAX(created) as created, employee_id
FROM skills
GROUP BY employee_id
) s1
on s.employee_id = s1.employee_id
and s.created = s1.created
left join Competencies c
on s.competency_id = c.id
See SQL Fiddle with Demo
Or another way to do this is to use row_number():
select *
from
(
select s.id SkillId,
s.employee_id,
s.competency_id,
s.created,
e.id employee,
e.first_name,
e.last_name,
c.id competency,
c.title,
row_number() over(partition by s.employee_id
order by s.created desc) rn
from Employees e
left join Skills s
on e.id = s.employee_id
left join Competencies c
on s.competency_id = c.id
) src
where rn = 1
See SQL Fiddle with Demo
For every non-aggregated column you add to your SELECT statement you need to update your GROUP BY to include it.
This article may help you understand why.
;WITH
MAX_SKILL_created AS
(
SELECT
MAX(skills.created) as created,
skills.employee_id
FROM
skills
GROUP BY
skills.employee_id
),
MAX_SKILL_id AS
(
SELECT
MAX(skills.id) as id,
skills.employee_id
FROM
skills
INNER JOIN MAX_SKILL_created
ON MAX_SKILL_created.employee_id = skills.employee_id
AND MAX_SKILL_created.created = skills.created
GROUP BY
skills.employee_id
)
SELECT
* -- type all your columns here
FROM
employees
INNER JOIN MAX_SKILL_id
ON MAX_SKILL_id.employee_id = employees.employee_id
INNER JOIN skills
ON skills.id = MAX_SKILL_id.id
INNER JOIN competencies
ON competencies.id = skills.competency_id
If you are using SQL Server than you can use OUTER APPLY
SELECT *
FROM employees E
OUTER APPLY (
SELECT TOP 1 *
FROM skills
WHERE employee_id = E.id
ORDER BY created DESC
) S
INNER JOIN competencies C
ON C.id = S.competency_id