Answer simple quiz at the end of the blog post and -
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Finding un-matching Records
Often time we want to find records in one table that have no matching key in another table. This is common for things like finding products that have never sold, or students who did not re-enroll. Something we were expecting is missing. Records in one table were expecting some related activity in another table and did not find them. There are many ways to find these records.
Basic Subquery
We have probably all heard that subqueries should be avoided if there is a better solution. Often times basic subqueries are used where a simple “Unmatched Records Query” could have been used.
Let’s start off with the subquery example. Looking at the Location table in the figure below we see all the data. In fact, this table does not allow nulls for the LocationID field. Looking further, there are no nulls anywhere in the Location table. So does this mean that all locations have at least one employee? It’s possible that some of these locations might be new and have not employees working there yet.
How can we find the location with no employees. We can use a subquery. For example we can use the following query to find all locations of the JProCo database that have now employee working there.
SELECT *
FROM Location
WHERE LocationID
NOT IN (SELECT DISTINCT LocationID
FROM Employee
WHERE LocationID IS NOT NULL)
Unmatched Records Queries
If you wanted to find all locations with no employees, you could run an “Unmatched Records Query”. Let’s build this piece by piece. In this case, we have to join the Location table with the Employee table to determine the location that has no employees. What type of join will tell us this? Since nulls don’t map through a join, the INNER JOIN drops the record from the result set and we won’t see Chicago. The outer join will show both the matches and the unmatched records, so we see every location. In the figure below we get all location even if there are no employees.
Notice Seattle is listed many times but Chicago is listed once with no employees found. A NULL appears in the fields from the Employee table for Chicago. With the Location table on the left and the NULL on the right, we have part of an unmatched records query. To find just the records that don’t match, we look for null records on the table that the outer join does not favor. In this case, it’s the Employee table.
The outer join will show us the unmatched records with null location details if you set the WHERE clause to look for nulls on a field in the non-dominant table. Unmatched record queries use SQL to return a result set displaying only the unmatched records between the two tables.
When our query criterion specifies NULL, only Chicago shows up in our result set. By doing a LEFT OUTER JOIN and using a NULL value from the Employee table (or “RIGHT” table) as our search condition criteria, our unmatched records query shows us one record.
Note: If you want to setup the sample JProCo database on your system you can watch this video.
Question 5
Q 5) Which of the following queries will show all location that have no employees?
- SELECT P.EmployeeID, T.[Name]
FROM Employee P LEFT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE T.TerritoryID IS NULL - SELECT P.EmployeeID, T.[Name]
FROM Employee P LEFT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL - SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE T.TerritoryID IS NULL - SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
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Reference: Pinal Dave (http://blog.SQLAuthority.com)
Q 5) Which of the following queries will show all location that have no employees?
4. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Leo Pius
USA
The correct answer is No. 4, as the RIGHT OUTER JOIN using a NULL value from the LEFT table as the search condition criteria will produce just the locations with no employees.
Rene Castro
El Salvador
Correct Answer is Option 4:
– Gets all the employees that have no location assigned to
1.SELECT P.EmployeeID, T.[Name]
FROM Employee P LEFT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE T.TerritoryID IS NULL
– Gets all the employees that have no location assigned to
2.SELECT P.EmployeeID, T.[Name]
FROM Employee P LEFT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
– This query doesn’t return any data becuase TerritoryID won’t be NULL (if it is a Primary Key)
3.SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE T.TerritoryID IS NULL
– Gets all locations that have no employees
4.SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Country – INDIA
Answer 4 is right. As Employee is a child Table and Location is Main Table, so Location must have data with Employee. With Employee on Left Side will not give correct data so have to use opposite of Left Join that is Right Join.
I am from New Delhi, India
Correct Answer is option : 3
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE T.TerritoryID IS NULL
Thanks,
Dhruval Shah, Ahmedabad, India
Correct Answer is option : 4
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Thanks,
Dhruval Shah, Ahmedabad, India
Correct Answer is # 4.
4. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL;
Here, RIGHT OUTER JOIN using a NULL value from the LEFT (Employee) table as the search condition criteria will produce just the locations with no employees.
Gopalakrishnan Arthanarisamy
Bangalore, India
Correct option is 4
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Varinder Sandhu (India)
The answer is No.4
David Hunter
USA
Right Answer is Option 4
4. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Neelesh Jain
India
whoever has read following link, wouldn’t have problem in answering this question.
http://blog.sqlauthority.com/2009/04/13/sql-server-introduction-to-joins-basic-of-joins/
Actually we are focused on Location table as we need location so we are going to use RIGHT OUTER JOIN in this case, if we will use RIGHT OUTER JOIN, we will get all records from LOCATION table and It will return all employee with respected location. if any records of LOCATION table won’t have employee, it will come with NULL in EMPLOYEEID and of course in TerritoryID too. so we are going to get all LOCATION which has no matching record in EMPLOYEE table with condition “P.TerritoryID IS NULL”. so our choice should on Option # 4.
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Ritesh Shah(India)
Question 5
Ans : 4- SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Aditya
Chennai, INDIA
Answer 4:
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Kulwant kumar
Delhi
The option 4 is the answer.
Country – USA.
The Correct answer is 4.
4.SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Ravi
Bangalore – India
The answer is
4. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Country :India[Ahmedabad]
Corrent Ans is Option 4:
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Pratik Raval
India
Answer:
4. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Lalit
India
Correct Answer is Option 4:
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
India
The correct answer is 4.
Right outer join gets all matching records from both Employee and Location table based on territory id and non matching records from Location table and again there is filter based on territory id = null which will be able to fetch all locations that have no employees.
Question 5
Q 5) Which of the following queries will show all location that have no employees?
Answer is 2 and 4
because we are looking for locations that have no employees below query uses right outer join and Look at the where condition we have specified and looking for TerritoryId in Employee table i.e P.TerritoryId as null.
4. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
below query uses left outer join and mentioned P.TerritoryID IS NULL
in where clause.gives correct result.
2. SELECT P.EmployeeID, T.[Name]
FROM Employee P LEFT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Following are wrong :
below query uses T.TerritoryID IS NULL T—>Location in where clause,
Looks for the TerritoryID as null in location table, If that table don’t have null for the TerritoryID gives zero records.
1. SELECT P.EmployeeID, T.[Name]
FROM Employee P LEFT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE T.TerritoryID IS NULL
Blow query uses RIGHT OUTER JOIN with Location and looking for TerritoryID IS NULL in Location table which gives wrong result.
3. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE T.TerritoryID IS NULL
Country:India
Answer for question 5:
Above all option will give error, since the above all option join with common column TerritoryID which is not there in employee table nor in location table
INDIA
Brijesh
Correct , I have not looked at the table columns .It definitely produce an error.
None of option is correct.
The correct answer is option 4. that is
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Here we have used right outer join it means it will bring all records from Location Table and will fatch NULL wherever TerritoryID is NULL for Employee table. So we can match records from Employee table which have TerritoryID as null.
From
INDIA
AHMEDABAD
The correct option is 4.
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Gets all locations that have no employees. The where condition will list all the territoryID from right table(i.e. Employee Table) which contains null values
By
Yasodha.N (India)
Option No. 4 is correct:
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Country- India
OPTION 2 & 4 is Right
2. SELECT P.EmployeeID, T.[Name]
FROM Employee P LEFT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
4..SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Ans:
4. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
This queries will show all location that have no employees.
Partha
India
Hi,
4th is Correct:
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
I am from India
I think option 4 is the correct answer
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Country- India
Correct Answer is option : 4
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
India
The Correct Answer is Option-4
Thanks
Narendra (India)
Correct answer is option 4.
4. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Country – India
Correct option is 4.
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
India
Shilpa Sharma
4. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL;
Here right outer join with null give the value of Location which is not having employee
Ghanshyam
Bangalore, India
The 1, 2 3 are wrong
Bocs
1. will give the employees list whose Territory ID not in Location table
and employees whose territory ID is null in employee table
2. will give the employees list whose territory ID is null in employee table
3. will give the records which having territoryID is null in location table
(If the location table permits null values to the TerritoryID column)
So option 4 is the correct answer
4. which will Give list of location which have no employees
and If the location table permits null values to the TerritoryID column
those rows also will include.
Govindaraj P bangalore India.
The correct option is 4.
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Gets all locations that have no employees. The where condition will list all the territoryID from right table(i.e. Employee Table) which contains null values
From
Malay Shah
Ahmedabad (India)
The correct option is 4.
When we apply right join then the result is all row from right table which is location in our case and respective match records from the left table and null in case of no match.
And applying the where cause of null (P.TerritoryID IS NULL) will only select result having employees with location null
Karan
India
Option 4 is correct
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Country INDIA
Answer is Option# 4.
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Soumya Ranjan Das,
Bhubaneswar, India
The answer is:
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
First two options does not work because, it is LEFT OUTER JOIN. If we do this, in the first step itself it does not show the location which does not have employee.
Thirst option does not work because, it is checking for ‘T.TerritoryID IS NULL’ which is can not be null.
So the fourth option will meet the requirement.
Country: India
Hi Pinal,
Correct Answer is Option 4
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Thanks,
Fazal(India)
Correct answer is option 4
Correct Answer is Option 4
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Jankhana
India
Answer :
4.SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Thanks
Pawan
Country: India
Correct answer:(4)
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
by kkmishra
Answer is (4)
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
by kkmjssate
unnao(India)
The Correct Answer is
4.SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
As Right Outer Join considers all the records from Right table which is Location and Matching Records from Left Table which is employees.
Where condition will filter out data of employee table and
Query retireves Locations which is not associated with Employee Table.
Location: India
The Correct answer is Option 4
4.SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
cheers,
Prasad Yangamuni
INDIA (Pune)
[...] Q 5) SQL SERVER – Tips from the SQL Joes 2 Pros Development Series – Finding un-matching Records – … [...]
he correct option is 4.
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
From
Vishal India
The Correct answer is 4.
4.SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Somnath Desai
India
Hi ,
I think this 4th option willl work fine only when there TerritoryId column is found in both tables we are joining,
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Correct Answer is Option 4 as we are looking for records where there are no employee in territory hence p.TerritoryID should be NULL and all the records are brought from Location table.
Krunal K. Doshi
INDIA
Correct Answer is 4 i.e
4. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
I’m from india
Answer : 4
City: Mumbai
Country: India
The answer is No.4
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
we are using right join here, that means all the records from Location table will come into output (whether they have matching record in employee or not), finally we check the employee table’s territory id for null to retrieve only those record which are not having the employee in that location.
India
Correct answer – 4
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Shekhar Gurav.
Country – INDIA
Correct Answer is Option 4
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Explanation : As in this query we have right outer join between Employee and Location Tables which will take all rows from location table irrespective of matching ‘TerritoryID’ rows from Employee Table. When the rows from Employee table doesn’t match with the ‘TerritoryID’ of Location Table then that row will be shown as NULL. And such rows are filtered by condition ‘P.TerritoryID IS NULL’. So this query will list all locations with no employees.
Country – INDIA (Gujarat)
Correct Answer: #4
Country of residence: India
Correct Answer is # 4
City: Ahmedabad
Country: India
Good One …
Correct Answer:
4. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
India (Bangalore).
Answer : 4
Country : India
Correct Answer is 4 i.e
4. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Right outer join forces query statement to display records of right table with records of another table having some matching criteria.
So we want to find all locations that’s why
“Employee P RIGHT OUTER JOIN Location T” this statement is correct & next statement WHERE P.TerritoryID IS NULL gives result with all locations having no any Employee.
I’m from india (Pune)
Sunny Jagtap.
Hi All
Ans # 4 is right
Ahmedbad-INDIA
Answer : 4
Country : India
Option 4 is the correct one.
Country India
Answer is: 4
4. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Country : india
The correct option is 4.
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Country: India
Varun
Answer: Option 4
Because Employee table is Right Outer Join with Location Table and having a condition on territory Id from Employee table which is nothing but the Location table is left outer join with Employee table and territory is null in employee table.
India
Answer: Option 4
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Country: India(sikha)
Answer 4 is correct answer
Correct answer :
Option 4:
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Thanks,
Mandar
Mumbai,INDIA
Answer 4 is correct answer
Abhishek Mishra
Country India
Option 4 is the correct Answer
4.SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Country: INDIA
Question 5
Q 5) Which of the following queries will show all location that have no employees?
Answer:
4.SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Answerer: Sivaprasad S
Country: India
The correct answer is:
4.SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Country: United States
The correct answer is #4
USA
Mike Michalicek
Hi Pinal Dev,
The correct answer is Option 4,
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
The First two option is Left Outer join which is an invalid answer for the question as the Territory Id will never be shown up when we do a left outer join.
And the 3 Option is trying to find where TerritoryId is null in the location table which is not possible as Location is the master table.
P.Anish Shenoy
INDIA, Bangalore Karnataka
4. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Divesh
INDIA
Correct answer is option 4
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
RIGHT OUTER JOIN will give all the records from location table and matching records from employee table. Where condition will filter data from employee table and result will be locations which are not in employee table.
Hiren Bavishi
India
3. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE T.TerritoryID IS NULL
correct answer is 4
India
answer-4
In case of LEFT OUTER JOIN : It will result all the records from the left table irrespective of the records in the right table
Simillarly, in RIGHT OUTER JOIN : it will result all the records from the right table irrespective of the records in the left table
1. We have to take all the records from the Location, hence we can take left outer join having Location in the left or right outer join having Location in the right
2. We have to show the locations having no employees, hence we have to put
in where condition Employee.TerritoryID is null
Above two conditions are satisfied only in Option – 4
So, Correct Answer is Option 4
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Ishan Shah,
Gandhinagar,
India
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
We have to use Right Outer Join to get data from Location table and where clause to check NULL value must be on Employee table.
Chetan – USA
Answer is : 1, 3
India
Hi Pinal,
Challenge:
Which of the following queries will show all location that have no employees?
Correct Answer:
4.SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
The RIGHT OUTER JOIN will get all of the Location Records. The Where clause will filter the results to show only the Location Records that don’t have employees (WHERE P.TerritoryID IS NULL).
Country:
United States
Thanks for the knowledge!
Regards,
Bill Pepping
Option #4 is the correct answer
Thanks,
Kunal
Florida, USA
Option 4 is the correct answer.
Jason Markantes
USA
Answer #4 –
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
you need the RIGHT OUTER JOIN so you can get locations without employees, but you also need to be checking the employee table for the null TerritoryID. Checking the location table for the null TerritoryID won’t return anything since all locations will have an ID
I believe the correct answer is 4.
The first two are doing a left outer join which would get employees without location rather than locations without employees.
The third one is close, but it is checking for nulls on the wrong table. The table is P for employee, not t for Territory. With number 4 you would see the rows that have nulls in the Employee table.
I am from the United States.
Correct answer is option # 4
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Nikhil Bhatt, Tampa, FL, USA
the answer is 4
i m from india
The correct answer is 4.
left out join list all rows from left hand table plus null.
right out join list all rows from right hand table plus null.
So in this case, we want to know null employees, right out join is used here.
Country – Canada
Correct Answer is Option 4
Sandeep
INDIA
Option 4 is correct.
4.SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Right outer join returns the records only from the right table excluding the subset of primary and secondary table records and NULL on employee table returns rows that have no employees.
Country: USA
I think the answer for this case is option 4
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Country : Chile
Answer No 4 is correct:
“SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL”
—————–
Rajneesh Verma
INDIA
4.SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Gordon Kane
USA
Answer is Option no – 4
India
Option No 4 is correct:
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Country: India
Answer is 4.
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
David Brust
USA
Answer:
4.SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Vinay,Pune,India
4. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Ramdas
Charlotte,USA
The correct answer is number 4
USA
Hello Pinal,
The Correct option for the above question is : 4
OPTION 4:
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Detailed Explanation :
As in the above query we have right outer join between Employee and Location Tables which take’s all rows from Location table whether or not the matching ‘TerritoryID’ rows from the Employee Table.
When the rows from Employee table doesn’t equate or matches with the ‘TerritoryID’ of Location Table then that row will be shown as NULL. And such rows are filtered by condition ‘P.TerritoryID IS NULL’. So this query will display all locations with no employees (i.e.) it selects only result having employees with location null.
OPTION 1.This will return the employees record whose Territory ID not in Location table and employees whose territory ID is null in employee table
OPTION 2.This will return the employees record whose territory ID is null in employee table.
OPTION 3. This will return the records which are having the territoryID as null in location table (If the location table permits null values to the TerritoryID column).
So option 4 is the correct option.
DILIP KUMAR JENA
COUNTRY : INDIA
Answer is Option 4. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
(Sale, Nigeria)
Option 4
4.SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Explanation:- RIGHT OUTER JOIN will get all of the location records irrespective of Employee.
COUNTRY:- INDIA
Option 4 is the answer
Sweden
Thank you, Pinal Dave, for this interesting article. I can use this other view on finding un-mathching records in a query I (re)wrote yesterday.
I’ll continue reading your articles as they come.
Many thanks all the way from the Netherlands (Europe).
Ruud van de Beeten
The correct option is #4
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
It’s a bit of a tricky question as it’s not easy to de-cipher RIGHT JOIN as LEFT JOIN is usually simpler. I always would have written this query as NOT EXISTS.
I’m from USA
Option 4 is correct
India
Hi Pinal sir,
The correct answer for this question is option no. 4:
4. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Reason: We have to find out all the location that have no employee.
Above query is fulfilling all the criteria to provide expected results.
To have location with no employee we have to take a help of OUTER JOIN and from the result set of query we required Location id that is null (i.e. TerritoryID). We have RIGHT OUTER JOIN of Employee table with Location Table. Which will provide all the matching and mismatching rows from location table i.e all the location who have employee or not have a single employee.
And in Where clause we are finding TerritoryID of Employee table which is null.
And TerritoryID of Employee table is null only when there is no employee for respective location when used with right outer join.
Following options are not correct because:
Option 1:
SELECT P.EmployeeID, T.[Name]
FROM Employee P LEFT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE T.TerritoryID IS NULL
TerritoryID will be not null for location table.
Option 2.
SELECT P.EmployeeID, T.[Name]
FROM Employee P LEFT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Left outer join is used for employee table with location table and TerrirotyID will not be null for employee table.
Option 3.
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE T.TerritoryID IS NULL
TerritoryID will be not null for location table.
Regard$
Chirag Satasiya
The right answer for this Question is:
4. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL;
The right outer join with null give the value of Location which is not having employee
Paurav
Surat, India
ELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
4. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL;
4.SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Sudeepta,
USA
Q 5) SQL SERVER – Tips from the SQL Joes 2 Pros Development Series – Finding un-matching Records – Day 5 of 35
Since we want all Location (with no employees) we need to favor the Employee table so (1) and (4) are incorrect. We are not looking for null location making (3) incorrect too. The Location table on the right and a null employee on the left would find the unmatched record from the Location table so (4) is correct.
Winner from USA: Naomi
Winner from India: Ritesh Shah
I thank you all for participating here. The permanent record of this update is posted on facebook page.
Option 4 is Right
Country india
The answer is 4:
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
The right outer join gives us all of the matched and unmatched locations when joining to the employee table. Filtering for a null value in the employee table will give us all locations where no employees are at.
Country of Residence: USA
[...] Q 5) SQL SERVER – Tips from the SQL Joes 2 Pros Development Series – Finding un-matching Records – … [...]
Answer 4.
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Ashish, India
4.SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
HELLO GUYS
WHEN I WROTE THIS QUERY I WAS VERY EXITING
REQIREMENT:-
I WANT TO GET THE PATIENT DETAILS(;TABLE :- PATIENT)
BUT THESE PATIENT SHOULD NOT IN ADMISSION(;TABLE :- ADT_ADMN)
IN CASE THE ADMISSION PATIENTS ARE IN DISCHARGE(;TABLE :- ADT_DSCHRG) I WANT THE RESULT SET
QUERY:-
CREATE TABLE PATIENT(PATIENT_ID INT IDENTITY,
FIRST_NAME VARCHAR(20),
LAST_NAME VARCHAR(20),
PATIENT_NAME AS(FIRST_NAME+’ ‘+LAST_NAME))
GO
CREATE TABLE ADT_ADMN(ADMN_ID INT IDENTITY,
PATIENT_ID INT)
GO
CREATE TABLE ADT_DSCHRG(DSCHRG_ID INT IDENTITY,
PATIENT_ID INT)
GO
SELECT *
FROM PATIENT P
LEFT JOIN ( SELECT AA.PATIENT_ID
FROM DBO.ADT_ADMN AA
LEFT JOIN DBO.ADT_DSCHRG AD ON AA.ADMN_ID = AD.ADMN_ID
WHERE AD.DSCHRG_ID IS NULL
)AS AAAD ON P.PATIENT_ID = AAAD.PATIENT_ID
WHERE P.PATIENT_ID IS NULL
Right is # 4
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Francisco,
Miami
Option 4
I am from India
Answer is #4:
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Thanks,
Wayne
answer is # 4:
SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
atul singh
i’,m from india(mumbai)
answer Option: 4
Raghavendra (USA)
Ans :4 SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
India
Hi Pinal,
I really enjoy your blog and have found answers to many questions here.
Regarding this post about finding unmatched records, why didn’t you use the (new to 2008) EXCEPT? It’s very useful and I have found it to be quicker than using a subquery.
Kind Regards,
Connie OI
Option 4. SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
INDIA
Ans 4) SELECT P.EmployeeID, T.[Name]
FROM Employee P RIGHT OUTER JOIN Location T
ON T.TerritoryID = P.TerritoryID
WHERE P.TerritoryID IS NULL
Country : India
[...] SQL Joes 2 Pros Development Series – Finding un-matching Records [...]
Thanks Pinal – I just had to do this very thing yesterday and only knew to write a subquery. I just tried your above method and it worked very well. Thanks for the article!
Please solve my query..
write a query to display all the employees from emp table in which ‘i’ is not existing in their names.
write a query to list all the emps whose names starts with S or K without using or operator.
In database we are having table products with column prod_desc and prod_desc having below values
10tea
coffee20
please write a query to disply the below output.
prod_desc id name
10tea 10 tea
coffee20 20 coffee