I have two tables one is teacher and another is Department which is mentioned below.
Teacher Table
Id Name
1 xyz
2. Gjd
3. Dftr
4 dhdk
Department Table
Id Name EMPID
1 SQL. 2
2. PHP. 4
3. JAVA. 1
4 PEARL. 5
QUESTION
i want those records of teacher which are not link with any Department.
you can use following statement using left join then filter Teacher that not matched
SELECT t.*
FROM Teacher t
left join Department d on d.EMPID = t.Id
where d.id is null
SELECT * FROM teachers WHERE
id NOT IN (SELECT DISTINCT EMPID FROM departments) ;
Hope this helps.!!
you can do it by inner query..
select * from teacher where id not in (select empid from department);
Related
I'm trying to write sql query which return me subject_id(result table) where primary_skill(student table) is unique.
Result table has column (student_id, subject_id, mark)
My query:
SELECT r.subject_id
FROM result r
JOIN student s ON r.student_id = s.student_id
WHERE s.primary_skill IN (SELECT DISTINCT primary_skill
FROM student)
GROUP BY 1;
I have this result:
subject_id
1
2
3
4
5
6
7
8
9
10
1001
But I should return only id 1001, because only this subject has unique student primary_skill, in other ids primary skill are repeated.
What am I doing wrong? How it improve?
Please try following:
select result.subject_id from student
join result on student.id =result.student_id where
student.primary_skill in
(select primary_skill from student group by primary_skill having COUNT(*)=1)
If I understand this right, you want results for students only having one skill. You can use GROUP BY and a HAVING clause checking for the count of skill being equal to one for this.
SELECT r.subject_id
FROM result r
INNER JOIN (SELECT s.student_id
FROM student s
GROUP BY s.student_id
HAVING count(DISTINCT s.primary_skill) = 1) x
ON x.student_id = r.student_id;
A Pupil table with { ID, LastName}
a Subject Table with {ID, SubjectName}
and a Report Table with {ID, PupilID, SubjectID, Grade}
There is a one-to-many relationship between Pupil and Report Tables, and Subject and Report Tables.
I want to generate a table like this for say subjectID = 1
Pupil.ID Pupil.LastName SubjectID Grade
1 --------------Smith ---------- 1 ------------B
2 --------------Jones ---------- 1 ------------NULL
3 -------------Weston ----------1 ------------NULL
4 -------------Knightly ---------1 -----------A
The problem is that the Report table would contain just 2 entries for subject 1:
PupilID SubjectID Grade
----1------- 1 ----------- B
----4------- 1 ----------- A
Left joins don't seem to work since there are only 2 entries in the report table for subject 1
SAMPLE DATA
{Pupil Table}
ID LastName
1 ...Smith
2 ...Jones
3 ...Weston
4 ...Knightly
{Subject Table}
ID SubjectName
1 ....Maths
2 ....Physics
3 ....Chemistry
{Report Table}
ID PupilID SubjectID Grade
1 .......1 ..........1 ..........B
2 .......4 ..........1 ..........A
When I do a search on SubjectID = 1 I want the table:
Pupil.ID .......Pupil.LastName ........SubjectID ...........Grade
1 --------------Smith ---------- 1 ------------B
2 --------------Jones ---------- 1 ------------NULL
3 -------------Weston ----------1 ------------NULL
4 -------------Knightly ---------1 -----------A
Access doesn't do subqueries very easily, so everything gets crammed into the FROM clause with a series of wrapped parentheses. Based on your sample data and my fighting Access to stop being unnecessarily difficult, I came up with this:
SELECT ps.Pupil_ID, ps.LastName, ps.Subject_ID, r.Grade
FROM (SELECT * FROM (SELECT ID AS Pupil_ID, LastName FROM Pupil) p,
(SELECT DISTINCT ID AS Subject_ID FROM Subject)) ps
LEFT JOIN REPORT r ON r.PupilID = ps.Pupil_ID AND r.SubjectID = ps.Subject_ID
ORDER BY Pupil_ID, Subject_ID;
The subquery "ps" is a cartesian join of the Pupil and Subject table views that I specified. At this point, your query would look like this:
(LastName column not shown for clarity)
StudentID|SubjectID
1 1
1 2
1 3
2 1
2 2
2 3
3 1
3 2
3 3
Now, using that Cartesian join subquery (pupilstudent -> ps), I use a LEFT JOIN to assign the Report table to each unique student's ID and subject ID. Therefore, if a student did not take a particular class, there will be a NULL value in the final result.
I tested this in Access using your sample data and it works on my machine.
Also as a note, it is poor practice to have a field called just ID in each table (e.g. in the Pupil table, ID becomes PupilID). This makes it much easier to use, and it self documents.
Cross join pupil and subject tables and left join result to report table
What you need is a cross join:
SELECT Pupil.ID, Pupil.LastName, SubjectID, Grade FROM
Pupil, Subject LEFT JOIN Report ON Subject.ID=Report.SubjectID
WHERE Subject.ID=1
To combine every pupil with every (or with a particular) subject, use cross join; Then use left join to get the corresponding grades:
select *
from pupil p cross join (select * from subject where id = 1) s
left join report on subjectId = s.id and pupilId = p.id
I have two tables I want to display student without results
Student tables
Sname snumber
A 1
B 2
C 3
G 4
And results table
Snumber marks
1 90
4 60
I have the following code
Select student.sname from student
Join results
On student.snumber=results.snumber
Its showing students With results. I want student without results which is B and C
Try this,
Select student.sname
from student
LEFT Join results
On student.snumber=results.snumber
WHERE results.snumber is null
If you want all the students then remove the where clause.
After LEFT JOIN solution (#Jatin Patel), you can see NOT EXISTS one:
SELECT *
FROM Students S
WHERE NOT EXISTS(SELECT * FROM results R WHERE S.snumber=R.snumber)
I have Parent table and multiple child tables with foreign key constraint.
School Table
School ID EduDetails Genders Address_id EDUTYPE
1 2 M 3 FGN
And the child tables like
Education Details
EDU ID EducationType
2 Online
AKA Name
School Id AKA Name
1 Test School
1 School Test
Gender Table
Gender ID Gender Desc
M Male
I am using Left outer join for the parent and school table to fetch the results.
But My issue is, If AKA table has 5 counts matching the school Id and Gender table has only 1 records for that school Id.
So the results comes with 5 duplicate rows with school Information and also other child table information.
Is there any workaround to fix this issue. I tried using subquery and row_number over by function. But it is not working for me. Can anybody help me to solve this issue.
Thanks in advance for your time in looking this issue.
My required output should be like this
School_id AKA Name GenderDesc EductaionType
1 Test School Male Online
1 School Test
So I need to have Null values for the not matching records.
Since you want all the records in the AKA Name table, I've joined on that getting a Row_Number for each row. Then using that Row_Number, LEFT JOIN on the other tables.
SELECT S.SchoolId,
SA.AKAName,
G.GenderName,
ED.EducationType
FROM School s
JOIN
(SELECT SchoolId,
AKAName,
ROW_NUMBER() OVER (PARTITION BY SchoolId ORDER BY AKAName) rn
FROM SchoolAKA
) SA ON S.SchoolID = SA.SchoolId
LEFT JOIN
(SELECT EDUID,
EducationType,
ROW_NUMBER() OVER (ORDER BY EducationType) rn
FROM EduDetails
) ED ON S.EDUID = ED.EDUID AND SA.rn = ED.rn
LEFT JOIN
(SELECT GenderId,
GenderName,
ROW_NUMBER() OVER (ORDER BY GenderName) rn
FROM Genders
) G ON S.GenderId = G.GenderId AND SA.rn = G.rn
Here is the SQL Fiddle.
And here are the results:
SCHOOLID AKANAME GENDERNAME EDUCATIONTYPE
1 School Test Male Online
1 Test School (null) (null)
In a table that stores multiple rows per employee, I want to pull one row per employee that represents the most recent entry for each employee. Here's where I am with hand-written SQL:
SELECT [all the selected columns here]
FROM Nominations t
inner join
(select max(NominationId) mostRecentNominationId,
EmployeeId from Nominations group by EmployeeId) n
on n.mostRecentNominationId = t_.NominationId
From source data like this:
nomination_id employee_id
-------------------------------
1 5
2 5
4 10
7 10
That'll give me something like this:
nomination_id employee_id
-------------------------------
2 5
7 10
I haven't been able to figure out how to accomplish that type of query via NHibernate ICriteria. Any thoughts?
Here is what you need to do:
DetachedCriteria dCriteria = DetachedCriteria.For<Nomination>("nomination")
.SetProjection(Projections.Max("nomination.Id"))
.Add(Restrictions.EqProperty("nomination.EmployeeId", "employee.Id"));
var nominations = Session.CreateCriteria<Nomination>("nom")
.CreateCriteria("Employee", "employee")
.Add(Subqueries.PropertyEq("nom.Id", dCriteria)).List<Nomination>();
This is not equilevant to the SQL query providfed in the question but it does exactly the same thing.
The SQL query that is generated by the above criteria query is:
SELECT *
FROM Nomination nom
inner join Employee employee on nom.EmployeeId=employee.EmployeeId
WHERE nom.NominationId =
(SELECT max(nomination.NominationId) as maxID
FROM Nomination nomination
WHERE nomination.EmployeeId = employee.EmployeeId)