linq query problem

Question

 BOOK_ID (PK & FK)

PRICE_ON_START

 PRICE_PLUS_COST

PRICE_PLUS_EXTRA

 PRICE_TOTAL

 

 

 BOOK_ID (PK)

 USER_ID (FK)

GROUP

 PHONE

 LOCAL_ID

 

 USER_ID (PK)

 NAME   

 SURNAME

 SEX      

 ISACTIVE

 

 

Hello there,

 

I have got problem, because I don't know how to get required records.

So,  as you can see guys I have three tables, and my question is how to get for particular USER_ID all records from Table1 where GROUP number in second table is for ex == 4.

It means, that for each of the 12 groups I have different values in table1

 

BOOK_ID in the first and second table is the same number of course.

 

I'm trying something like that, but this not working :(

 

var collection1 = from a in table1 from b in table2 where a.book_id == b.book_id && a.user_id == 1 select b

and now I would like to do something like that 

 

var result =  from b in table2 from c in collection1 where b.book_id == c.book_id && b.group == 6 select b?

 

 

Please help...