Want to protect your cyber security and still get fast solutions? Ask a secure question today.Go Premium

x
?
Solved

total number of records from another table

Posted on 2014-01-07
6
Medium Priority
?
268 Views
Last Modified: 2014-01-07
hi experts, i hope i get solution
i have 2 table with one to many relation ship,

Courses                      Employees
------------                   ---------------
ID                               CourseID
Name                         EmployeeName
-------------------------------------------------

Course                       Employees
--------------------        ----------------------------------------
ID          Name          CourseID         EmployeeName
--------------------        ----------------------------------------
1           course1            1                 emp1
2           course2            1                 emp2
                                      2                 emp3
                                      2                 emp4
                                      2                 emp5
-------------------------------------------------------------------

i need to write an sql statement that will return
course ID, course Name, Total number of employee in each course

result:
ID         Name          Emp_Total_No.
---------------------------------------------
1           course1           2
2           course2           3
---------------------------------------------

is there any solution to write it in a single query

looking forward for your suggestions

thank you
0
Comment
Question by:AZZA-KHAMEES
6 Comments
 
LVL 25

Accepted Solution

by:
Lee Savidge earned 2000 total points
ID: 39761822
Simplest way is a nested query. Haven't tested it but you get the idea.

select ID,
       Name,
       (select count(e.EmployeeName)
          from Emp_Total_No e
         where c.id = e.CourseID
         group by e.EmployeeName) as Emp_Total_No
  from courses c

Open in new window

0
 
LVL 13

Expert Comment

by:Jeff Darling
ID: 39761843
Or you could use a join.

SELECT A.ID
	,A.NAME
	,Count(B.CourseID) AS Emp_Total_No
FROM courses A
JOIN Employees B ON A.ID = B.CourseID
GROUP BY B.courseID
	,A.ID
	,A.NAME

Open in new window

0
 
LVL 12

Expert Comment

by:Habib Pourfard
ID: 39761845
Subquery:
SELECT  ID ,
        Name ,
        ( SELECT    COUNT(CourseID)
          FROM      Employees
          WHERE     Employees.CourseID = Courses.ID
        ) Emp_Total_No
FROM    Courses

Open in new window

left join:
SELECT  C.ID ,
        C.Name ,
        COUNT(E.CourseID) Emp_Total_No
FROM    dbo.Courses C
        LEFT JOIN dbo.Employees E ON C.ID = E.CourseID
GROUP BY C.ID ,
        C.Name

Open in new window


PS.
 Lee Savidge's solution: no need to group by e.EmployeeName in subquery
jeffld's solution: no need to group BY B.courseID
0
What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

 
LVL 13

Expert Comment

by:Jeff Darling
ID: 39761859
Thanks Pourfard.  You are correct.

SELECT A.ID
	,A.NAME
	,Count(B.CourseID) AS Emp_Total_No
FROM courses A
JOIN Employees B ON A.ID = B.CourseID
GROUP BY A.ID
	,A.NAME

Open in new window

0
 
LVL 6

Expert Comment

by:Mahesh Bhutkar
ID: 39761904
SELECT ID, NAME, Count(CourseID) as Emp_Total_No.
FROM courses,Employees where ID = CourseID GROUP BY ID, NAME
0
 

Author Closing Comment

by:AZZA-KHAMEES
ID: 39761934
thanks
0

Featured Post

Free Tool: ZipGrep

ZipGrep is a utility that can list and search zip (.war, .ear, .jar, etc) archives for text patterns, without the need to extract the archive's contents.

One of a set of tools we're offering as a way to say thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Microsoft Access has a limit of 255 columns in a single table; SQL Server allows tables with over 255 columns, but reading that data is not necessarily simple.  The final solution for this task involved creating a custom text parser and then reading…
One of the most important things in an application is the query performance. This article intends to give you good tips to improve the performance of your queries.
Using examples as well as descriptions, and references to Books Online, show the different Recovery Models available in SQL Server and explain, as well as show how full, differential and transaction log backups are performed
Via a live example, show how to backup a database, simulate a failure backup the tail of the database transaction log and perform the restore.
Suggested Courses

571 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question