Question

So I have a table that has divisions and sub-divisions. The structure is as follows:

COMPANYID | DIVISIONID | DIVISION | PARENTID
    1     |     1      | North    | NULL
    1     |     2      | South    | NULL
    1     |     3      | East     | NULL
    1     |     4      | West     | NULL
    1     |     5      | Sales    | 1
    1     |     6      | Service  | 1
    1     |     7      | Sales    | 2
    1     |     8      | Service  | 2
    1     |     9      | Sales    | 3
    1     |     10     | Service  | 3
    1     |     11     | Sales    | 4
    1     |     12     | Service  | 4

The idea behind the table is that the data would indicate all of those divisions/subdivisions are the for the same company. Anything with a null PARENTID is a “Division” and anything that has a PARENTID is a “Sub-Division”. There will be a max of 2 tiers (Division –> Subdivision). This table would create the following hierarchy:

Company 1
    North
        Sales
        Service
    South
        Sales
        Service
    East
        Sales
        Service
    West
        Sales
        Service

I am trying to make an SSRS report that shows details about the company including a table with all the divisions and sub-divisions. I am using the following query to retrieve a list of all the divisions and subdivisions:

SELECT division, parentid
FROM division
WHERE companyid=@companyid

@companyid is a parameter for the report. My thought process is that I want create a table that has a Parent group and a Detail group where the Parent group would be all those rows that have a null PARENTID and then the Detail group would list all rows whose PARENTID equals the divisionid of Parent row. I’m just not sure how to set that up in the groups. Filters? Separate queries? Do it in the SQL query?

Any and all help is greatly appreciated! Thanks!

Answer 1

For a simple hierarchy with a maximum of 2 levels you can just join the table on itself:

SELECT D1.CompanyId, D1.DivisionId, D1.Division, D2.Division AS Subdivision
FROM DivisionTable D1
INNER JOIN DivisionTable D2 ON D1.DivisionId = D2.ParentId AND D1.CompanyId = D2.CompanyId
WHERE D1.CompanyId = @CompanyId