SSRS报表的SQL查询Visual Studio查询设计器

Question

Can someone please help with an SQL Query I am facing.

Currently I am using Visual Studio 2013 Query Designer for my SSRS reports and I'm trying to select Students that are enrolled at their current School. However when testing my query for a selected student, it is returning all possible schools and saying the student has attended all 317 of them which is incorrect. My question is how do I find the school that a student has attended/attending?

The query code is below:

SELECT Person.Firstname, Person.Surname, Company.Name AS School, Company.CompanyCategory, Student.StudentNumber
FROM   Student INNER JOIN
       Person ON Student.ID = Person.ID CROSS JOIN
       Company
WHERE  (Company.CompanyCategory = 'Delivery Location') AND (Student.StudentNumber = '....')

Answer 1

As Sandeep mentioned, you are cross joining to Company (I'm assuming this is school?). You'll probably have to INNER JOIN to Company and specify a JOIN clause. The table Student might have CompanyID or something? You can JOIN that on the Company.ID . So the query becomes something like this:

SELECT Person.Firstname, Person.Surname, Company.Name AS School, Company.CompanyCategory, Student.StudentNumber
FROM   Student INNER JOIN
       Person ON Student.ID = Person.ID INNER JOIN
       --Not sure if CompanyID is the right field
       Company ON Student.CompanyID = Company.ID
WHERE  (Company.CompanyCategory = 'Delivery Location') AND (Student.StudentNumber = '....')