The domain is:
company (id, name, adress)
employee (id, name, adress, company_id, expertise_id)
dependantrelative (id, name, employee_id)
expertise (id, name, class)
I want to know how to get the number of dependantrelatives of each employee who are unique experts in their respective companies.
The Query below does not return the correct answer. Can you help me?
SELECT DISTINCT dependantrelative.employee_id
, COUNT(*) AS qty_dependantrelatives
FROM dependantrelative
INNER JOIN employee
ON employee.id = dependantrelative.employee_id
GROUP BY dependantrelative.employee_id
I just tried out the Query below and it works, but I want to know if there is a faster and simple way of getting the answer.
SELECT employee.id
,COUNT(dependantrelative.employee_id) AS qty_dependantrelatives
FROM (
SELECT employee.company_id
, employee.expertise_id AS expert
, COUNT(employee.expertise_id)
FROM employee
GROUP BY employee.company_id
, employee.expertise_id
HAVING COUNT(employee.expertise_id)<2
) AS uniexpert
LEFT JOIN employee
ON employee.expertise_id = uniexpert.expert
LEFT JOIN salesorderdetail
ON dependantrelative.employee_id = employee.id
GROUP BY employee.id
ORDER BY employee.id
Related
Obtain the department table where more than 38 employees work.
select distinct department,(select count(employee_id)
from employees as e1
where e2.department= e1.department and
department is not null
having count(employee_id) > 38 )
from employees as e2;
It seems to look a lot easier. In any case, a sample data and the desired output wouldn't be superfluous.
Select department, count(distinct employee_id) as cnt
From employees
Group by department
Having count(distinct employee_id)>38
I have a table employees with columns:
company_id,
id,
opt_state (ceased_membership, ignition, opted_out, opted_in),
opt_out_on.
I want to query all companies where all employees opt-state is in ('ceased_membership', 'ignition', 'opted_out') and the date opt_out_on when last employee left.
I have tried this but it didn't work
select company_id from employees where id=all(select id from
employees
where opt_state in ('ceased_membership', 'ignition','opted_out')
Then I wrote this query below, which worked very well and gave me the resolution I was looking for. However, I'd like to ask here if this can be done differently, more elegantly.
SELECT
e.company_id
, max_opt_out
FROM (
SELECT DISTINCT
company_id
, count(id)
OVER (
PARTITION BY company_id ) opt_out
FROM employees
WHERE opt_state IN ('ceased_membership', 'ignition', 'opted_out')) e
LEFT JOIN (
SELECT
company_id
, count(id) opt_in
, max(opt_out_on) max_opt_out
FROM employees
GROUP BY company_id) S
ON e.company_id = s.company_id
WHERE e.opt_out = s.opt_in;
This seems like a good time to use the HAVING clause
SELECT company_id, max(opt_out_on)
FROM employees e
GROUP BY company_id
HAVING bool_and( opt_state in ('ceased_membership', 'ignition','opted_out'));
HAVING in a bit like a WHERE but the condition apples to whole GROUPS
bool_and is an agregate function that is only true when all the records in the group are result in true.
I'd say that you want to query a maximum out_out_on for each company that only have employees in a set of states, which means that do not have any employee not in a set of states.
So, translated to SQL:
select company_id, max(opt_out_on)
from employees e
where not exists(
select 1 from employees
where company_id=e.company_id
and opt_state not in ('ceased_membership', 'ignition','opted_out')
)
group by company_id;
I am creating some queries for my project, but I face some difficulties with the follow ones:
A SELECT statement containing a subquery to retrieve a list of Locations (location id and street_address) that have employees with higher salary than the average of their department. The list must contain the number of those employees and their total salary per location. Name these aggregates respectively "emp" and "totalsalary". The locations in the list must be ordered by location_id.
Select LOCATION_ID, STREET_ADDRESS
from HR.LOCATIONS IN
(Select Employee_id
from HR.Employees
Where Salary > round(avg(SALARY)))
order by location_id;
error: SQL command not properly ended
and the second query is the following
The JOB_HISTORY table can contain more than one entries for an employee who was hired more than once. Create a query to retrieve a list of Employees that were hired more than once. Include the columns EMPLOYEE_ID, LAST_NAME, FIRST_NAME and the aggregate "Times Hired".
SELECT FIRST_NAME,LAST_NAME,EMPLOYEE_ID,
count (*)as TIMES_HIRED
from HR.JOB_HISTORY, HR.EMPLOYEES
where EMPLOYEE_ID= LAST_NAME
having COUNT(*) >1;
error: not a single-group
Try these hope they help. I am making an assumption that employee table has Location_Id column. I am adding Employee_id to Group by to make sure you get correct TotalSalary:
Select LOCATION_ID, STREET_ADDRESS, Count(Employee_id) AS emp, SUM(salary) AS totalsalary
from HR.LOCATIONS INNER JOIN
(Select Employee_id, salary
from HR.Employees
Having Salary > round(avg(SALARY), 0)) AS Emp ON HR.LOCATION_ID = Emp.Location_ID
Group By LOCATION_ID, STREET_ADDRESS, Employee_id
order by location_id;
For the second question:
SELECT FIRST_NAME,LAST_NAME,EMPLOYEE_ID,
count(Employee_id) as TIMES_HIRED
from HR.JOB_HISTORY inner join HR.EMPLOYEES On JOB_HISTORY.Employee_id = Employees.Employee_id
Group By FIRST_NAME,LAST_NAME,EMPLOYEE_ID
Having count(Employee_id) >1;
I have a huge table that contains both shipping address information and billing address information. I can get unique shipping and billing addresses in two separate tables with the following:
SELECT DISTINCT ShipToName, ShipToAddress1, ShipToAddress2, ShipToAddress3, ShipToCity, ShipToZipCode
FROM Orders
ORDER BY Orders.ShipToName
SELECT DISTINCT BillToName, BillToAddress1, BillToAddress2, BillToAddress3, BillToCity, BillToZipCode
FROM Orders
ORDER BY Orders.BillToName
How can I get the distinct intersection of the two? I am unsure of the syntax.
something like this?
SELECT DISTINCT
toname, addr1, addr2, addr3, city, zip
FROM
(SELECT DISTINCT
ShipToName AS toName,
ShipToAddress1 AS addr1,
ShipToAddress2 AS addr2,
ShipToAddress3 AS addr3,
ShipToCity AS city,
ShipToZipCode AS zip
FROM
Orders
UNION ALL
SELECT DISTINCT
BillToName AS toName,
BillToAddress1 AS addr1,
BillToAddress2 AS addr2,
BillToAddress3 AS addr3,
BillToCity AS city,
BillToZipCode AS zip
FROM
Orders) o
ORDER BY ToName
You say "Intersection" but you accepted the Union answer so I guess you just want the UNION DISTINCT. No need for derived tables and the three DISTINCT. You can use the simple:
SELECT
ShipToName AS Name,
ShipToAddress1 AS Address1,
ShipToAddress2 AS Address2,
ShipToAddress3 AS Address3,
ShipToCity AS City,
ShipToZipCode AS ZipCode
FROM
Orders
UNION --- UNION means UNION DISTINCT
SELECT
BillToName
BillToAddress1,
BillToAddress2,
BillToAddress3,
BillToCity,
BillToZipCode
FROM
Orders
ORDER BY
Name ;
You can join both sets on all fields and this will return the records that match:
SELECT *
FROM Orders o1
INNER JOIN Orders o2
ON o1.ShipToName = o2.BillToName
AND o1.ShipToAddress1 = o2.BillToAddress1
AND o1.ShipToAddress2 = o2.BillToAddress2
AND o1.ShipToAddress3 = o2.BillToAddress3
AND o1.ShipToCity = o2.BillToCity
AND o1.ShipToZipCode = o2.BillToZipCode
Or you should be able to use INTERSECT:
SELECT ShipToName, ShipToAddress1, ShipToAddress2, ShipToAddress3, ShipToCity, ShipToZipCode
FROM Orders
INTERSECT
SELECT BillToName, BillToAddress1, BillToAddress2, BillToAddress3, BillToCity, BillToZipCode
FROM Orders
Or even a UNION query (UNION removes duplicates between two sets of data):
SELECT ShipToName, ShipToAddress1, ShipToAddress2, ShipToAddress3, ShipToCity, ShipToZipCode
FROM Orders
UNION
SELECT BillToName, BillToAddress1, BillToAddress2, BillToAddress3, BillToCity, BillToZipCode
FROM Orders
I am using t-sql. I have what I thought would be an easy search. There is a 1-to-many relationship between SalesPerson and TradeShow. 1 salesperson could have gone to many trade shows. I need to be able to search on the SalePerson. I also need to be able to search on the LAST trade show they attended. I thought I would be able to do simple join and group on their last trade show, but I can not display the City or State.
SELECT SalePersonID, FirstName, LastName, TradeShow.DateLastWent
FROM SalesPerson INNER JOIN
(SELECT SalePersonID, MAX(DateLastWent) AS DateLastWent
FROM TradeShow
GROUP BY SalesPersonID) AS TradeShow ON SalesPerson.SalePersonID= TradeShow.SalePersonID
This workds, but the Tradeshow also has city and State. I need to be able to search on and display city and state. But if I include them in the subquery, I have to include thm in an aggregate function, and if I do that, I get the incorrect city and state.
The tables are simple
SALEPERSON
salespersonID PK
firstname
lastname
TRADESHOW
tradeshowID PK
datelastwent
city
state
salespersonID FK
Re-word it: what you want is the salesperson, plus the information from the last show that they have been to.
Select
SalePersonID,
FirstName,
LastName,
TradeShow.DateLastWent,
TradeShow.City,
TradeShow.State
From
SalesPerson
Inner Join TradeShow
On SalesPerson.SalePersonID = TradeShow.SalePersonID
Where
TradeShow.TradeShowID =
(Select Top 1 Latest.TradeShowID
From TradeShow As Latest
Where SalesPerson.SalePersonID = Latest.SalePersonID
Order By Latest.DateLastWent Desc)
You can join TradeShow twice :
SELECT SalePersonID, FirstName, LastName, TS1.DateLastWent,
TS2.City, TS2.State
FROM SalesPerson INNER JOIN
(SELECT SalePersonID, MAX(DateLastWent) AS DateLastWent
FROM TradeShow
GROUP BY SalesPersonID
) AS TS1 ON (SalesPerson.SalePersonID= TradeShow.SalePersonID)
INNER JOIN TradeShow TS2 ON
(TS2.SalePersonID = TS1.SalePersonID AND TS2.DateLastWent = TS1.DateLastWent)
WHERE TS2.City = 'CityName'
There is likely a more elegant way to solve this, but my first thought is to simply grab the newest TradeShow record to join with
SELECT SalePersonID, FirstName, LastName, TradeShow.DateLastWent
FROM SalesPerson
INNER JOIN (
SELECT *
FROM (
SELECT TradeShowId, DateLastWent, City, State, SalesPersonId
FROM TradeShow
ORDER BY datelastwent DESC
)
WHERE ROWNUM <= 1
) ON SalesPerson.SalesPersonId = TradeShow.SalesPersonId
Edit
Oops... been playing with Oracle too much
ROW_NUMBER() OVER(order by date) or SELECT TOP X
would be thw SQL Server way for doing this... don't have an instance of SQL-Server running, but pretty sure the syntax ends up being something like
SELECT SalePersonID, FirstName, LastName, TradeShow.DateLastWent
FROM SalesPerson
INNER JOIN (
SELECT TradeShowId, DateLastWent, City, State, SalesPersonId, ROW_NUMBER() OVER(PARTITION BY TradeShow.SalesPersonId ORDER BY DateLastWent DESC) RowNumber
FROM TradeShow
) ON SalesPerson.SalesPersonId = TradeShow.SalesPersonId AN TradeShow.RowNumber = 1