Question

I have these tables

AssigenmentList –linksto —School,AgeGroup

Users will have birthday attached to it

1. AgeGroup in turn linked to many ages like AgeGroup 3-4 is linked to one to many with 3,4 in numerical format

Now i want all the Assignment list which are linked to particular SCHOOL belong to same age as the age of Child

Answer 1

As a general rule:

select a.*, b.*, c.* from 
    A a inner join B b on a.idB = b.id
        inner join C c on b.idC = c.id

You use inner join if a.idB must have match to add the row to the resultset. Left outer join if the mere presence of a.idB (left side) is enough to project the row.

The trick is to navigate from the starting table to the last joining the columns that ties them.