I have 4 tables in my db: incoming letters, outgoing letters, local letters and employee. In "letters" tables, there is a register_employee that have register this letter.
Every employee has his/her unique id (for example "3de9a23e-b927-4a27-a66a-c1f30b8c1464").
Tables look like this:
employee:
id first_name last_name age
incoming:
id register_employee summary letter adress date_sent
"Outgoing" and "local" tables look same as "incoming" table.
I need to count how many letters have been registered by each employee and which type.
Example results:
employee incoming outgoing local
Bob Marley 45 33 5
John Travolta 31 10 9
George Bush 98 15 38
I tried to use full joins and nested Select statments, but results that I have got are probably wrong cause I am getting millions of count for each employee (I don't have so many letters in db).
You can use OUTER JOIN and GROUP BY as follows:
-- Updated
You can use multiple sub-query:
select e.id, e.firstname,
(select count(*) from incoming i where i.register_employee = e.id) as incoming_letter,
(select count(*) from outgoing o where o.register_employee = e.id) as outgoing_letter,
(select count(*) from local l where l.register_employee = e.id) as local_letter
from employee e
We count the number of letters under different categories & left join them to the master employee table
select employee.first_name , t1.incoming, t2.outgoing, t3.local from (
select * from employee
left join
(select register_employee, count(*) as incoming from incoming_letters group by register_employee) t1 on employee.id = t1.register_employee
left join
(select register_employee, count(*) as outgoing from outgoing_letters group by register_employee) t2 on employee.id = t2.register_employee
left join
(select register_employee, count(*) as local from local group by register_employee) t3 on employee.id = t3.register_employee ) v
SELECT incom.id,incom.name,incom.incoming,out.outgoings,loc.local
FROM (SELECT
employees.id as id,
employees.short_name as name,
COUNT(incomings.register_employee) as incoming
FROM employees
LEFT JOIN incomings ON incomings.register_employee = employees.id)
GROUP BY employees.id, employees.short_name) as incom
LEFT JOIN (SELECT
employees.id as id,
COUNT(outgoings.register_employee) as outgoings
FROM employees
LEFT JOIN outgoings ON outgoings.register_employee = employees.id
GROUP BY employees.id) as out
ON incom.id=out.id
LEFT JOIN (SELECT
employees.id as id,
COUNT(local.register_employee) as local
FROM employees
LEFT JOIN outgoings ON local.register_employee = employees.id
GROUP BY employees.id) as loc
ON incom.id=loc.id;
Related
What I need:
I am looking for a solution that can give me all the Employee Id's that have the same EmailAddress Column (the filter needs to be by EmailAddress).
I want to know what are the Id's correspondent to the duplicated Email Addresses and retrieve that information.
Table Employee:
Id | PlNumber | EmailAddress | EmployeeBeginingDate | EmployedEndDate | Name UserId(FK) | CreatedBy | CreatedOn
SELECT a.Id,a.EmailAddress
FROM Employee a
INNER JOIN (SELECT
Employee.Id as EmployeeId,
Employee.EmailAddress as EmailAddress,
FROM Employee
GROUP BY Employee.Id,Employee.EmailAddress
HAVING count(Employee.EmailAddress) > 1
) b
ON a.Id= b.EmployeeId
ORDER BY a.Id
I am always getting an error:
the multi-part identifier could not be bound.
I know why the error is happening but I couldn't solve this.
UPDATE: After a few changes the query is returning 0 rows but I know it should return at least 3 rows that I have duplicate values.
Try the below query as you have an aliased table Employee as a. So in place of Employee, you have to use a.
SELECT a.Id, a.EmailAddress
FROM Employee a
INNER JOIN (SELECT
Employee.EmailAddress as EmailAddress
FROM Employee
GROUP BY Employee.EmailAddress
HAVING count(Employee.EmailAddress) > 1
) b
ON a.EmailAddress = b.EmailAddress
ORDER BY a.Id
Live db<>fiddle demo.
Assuming the ids are different on each row, I would go for exists:
SELECT e.Id, e.EmailAddress
FROM Employee e
WHERE EXISTS (SELECT 1
FROM Employee e2
WHERE e2.EmailAddress = e.EmailAddress AND
e2.Id <> e.Id
)
ORDER BY e.EmailAddress;
Or, if you want to know the number of matches, use window functions:
SELECT e.Id, e.EmailAddress, cnt
FROM (SELECT e.*, COUNT(*) OVER (PARTITION BY e.EmailAddress) as cnt
FROM Employee e
) e
WHERE cnt >= 2;
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...
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
I've always done this back asswards in PHP or ASAP, so I figure it's time to actually learn the proper way to do it in SQL. I have the following 4 tables in a database:
Category (Fields: CategoryNumber, Desc) (small table with 15 rows)
Media (Fields: MediaID, Desc, CategoryNumber, etc) (huge table with 15,000 rows)
Sales (Fields: Date, MediaID, EmployeeID etc) (huge table with 100,000 rows)
Employees (Fields: EmployeeID, Name, etc) (small table with only 20 rows)
Category only links to Media
Media has links to both Category and Sales.
Sales links to both the Media and Employee
Employee only links to Sales
What I would like to do is to write a query which tells me what categories a given employee has never sold any media in.
I can write a simple query that looks for unmatched data between 2 tables, but I have no clue how to do it when I'm dealing with 4 tables.
Thanks for your time and help!
Here's my suggestion:
select *
from Category c
where not exists (
select *
from Employee e
inner join Sales s on s.EmployeeId = e.EmployeeId
inner join Media m on m.MediaID = s.MediaID
where e.Name = 'Ryan' and m.CategoryNumber = c.CategoryNumber
)
To query all employes with the categories in which they didn't sell anything:
select e.EmployeeName, c.CategoryNumber
from Category c
cross join Employee e
where not exists (
select *
from Sales s
inner join Media m on m.MediaID = s.MediaID
where c.categoryNumber = m.CategoryNumber
and s.EmployeeId = e.EmployeeId
)
SELECT c.CategoryNumber, c.Desc
FROM Category c
WHERE NOT EXISTS
(
SELECT *
FROM Employees e
INNER JOIN Sales s on s.EmployeeID = e.EmployeeID
INNER JOIN Media m on m.MediaID = s.MediaID
WHERE e.Name = "Ryan"
AND m.CategoryNumber = c.CategoryNumber
)
MS Access evidently needs a lot of parentheses (thanks, Ryan!):
select *
from Category c
where not exists
( select *
from ( Employee e
inner join Sales s on (s.EmployeeId = e.EmployeeId))
inner join Media m on (m.MediaID = s.MediaID)
where (e.Name = 'Ryan' and m.CategoryNumber = c.CategoryNumber) )
select c.desc
from category
left outer join (select s.employeeid,m.categorynumber
from sales s
inner join media m on s.mediaid=m.mediaid
inner join employee e on e.employeeid=s.employeeid
where e.name = 'JOE'
group by employeeid,categorynumber) t on t.categorynumber=c.categorynumber
where s.employeeid is null
Modified Answer based on the solution provided by Carl in Access SQL Syntax:
select *
from Category c
where not exists (
select *
from (Employee e
inner join Sales s on (s.EmployeeId = e.EmployeeId))
inner join Media m on (m.MediaID = s.MediaID)
where (e.Name = 'Ryan' and m.CategoryNumber = c.CategoryNumber)
)