CODEWITHSUNDEEP
sqloracle-database
Nick Div
Nick Div

Reputation: 5628

I cant figure out a inner join in this case

  1. I have a table called as A that has a primary key A_ID
  2. I have a second table called as B that has a primary key B_ID and foreign key A_ID
  3. I have a third table called C that has a primary key C_ID and foreign key B_ID and a row called as names.

For my case lets assume table A has ID's 1-10 B has ID's 10-100 and c has ID's 100-1000

Now I want the following functionality: I want all names from table C that has B_ID which is has a foreign key A_ID=3

So basically lets say some names in table C would have B_ID 20,30,40,50,60 and in table B B-ID 20 and 30 have A-ID 3

So I want data from table C that has only B_ID's 20 and 30

I hope I was clear enough, I would have mentioned the query that I wrote but I dont want the reader to get confused any more.

Thanks in advance............

Upvotes: 0

Views: 30

Answers (2)

user275683
user275683

Reputation:

I'm not sure if I'm missing something but if all you want is data from table c based on information available in that table you don't need to join to other table unless you want to verify B_ID is present in table b

Select * from TableC where B_ID in (20,30)

Edit: here is entire join that will return all rows from table C where `B

SELECT C.*
    FROM A
    JOIN B
        ON A.A_ID = B.A_ID
        AND B.B_ID IN (20,30)
    JOIN C
        ON B.B_ID = C.B_ID
    WHERE A.A_ID = 3

Upvotes: 0

Patrick
Patrick

Reputation: 6958

Can you try this:

SELECT C.names
FROM C
    INNER JOIN B ON C.B_ID = B.B_ID
    INNER JOIN A ON B.A_ID = A.A_ID
WHERE A.A_ID = 3

Upvotes: 2

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