Joining 6 tables into single query? - sql

Question

Hey can anyone help me join the 5 tables below into a single query? I currently have the query below but is doesn't seem to work as if there are two products with the same ID inside the hires table all of the products are returned form the products table which is obviously wrong.
SELECT products.prod_id, products.title, products.price, product_types.name,
listagg(suppliers.name, ',') WITHIN GROUP(ORDER BY suppliers.name) suppliers
FROM products
INNER JOIN product_suppliers ON products.prod_id = product_suppluer.prod_id
INNER JOIN product_types ON product_types.type_id = products.type_id
INNER JOIN suppliers ON product_suppliers.supp_id = suppliers.supp_id
LEFT OUTER JOIN hires ON hires.prod_id = products.prod_id
WHERE (hires.hire_end < to_date('21-JAN-13') OR hires.hire_start > to_date('26-JAN-13'))
OR hires.prod_id IS NULL
GROUP BY products.prod_id, products.title, products.price, product_types.name
Table data:
PRODUCTS
--------------------------------------------
| Prod_ID | Title | Price | Type_ID |
|------------------------------------------|
| 1 | A | 5 | 1 |
| 2 | B | 7 | 1 |
| 3 | C | 3 | 2 |
| 4 | D | 3 | 3 |
|------------------------------------------|
PRODUCT_TYPES
----------------------
| Type_ID | Type |
|--------------------|
| 1 | TYPE_A |
| 2 | TYPE_B |
| 3 | TYPE_C |
| 4 | TYPE_D |
|--------------------|
PRODUCT_SUPPLIERS
-------------------------
| Prod_ID | Supp_ID |
|-----------------------|
| 1 | 1 |
| 1 | 2 |
| 2 | 2 |
| 3 | 3 |
| 4 | 4 |
|-----------------------|
SUPPLIERS
----------------------
| Supp_ID | Name |
|--------------------|
| 1 | SUPP_A |
| 2 | SUPP_B |
| 3 | SUPP_C |
| 4 | SUPP_D |
|--------------------|
HIRES
---------------------------------------------------------------
| Hire_ID | Prod_ID | Cust_ID | Hire_Start | Hire_End |
|-----------------------|------------|------------------------|
| 1 | 1 | 1 | 22-Jan-13 | 23-Jan-13 |
| 2 | 2 | 2 | 27-Jan-13 | 29-Jan-13 |
| 3 | 1 | 3 | 30-Jan-13 | 31-Jan-13 |
|-----------------------|------------|------------|-----------|
PRODUCTS
--------------------------------
| Cust_ID | Name | Phone |
|------------------------------|
| 1 | Cust_A | 555-666 |
| 2 | Cust_B | 444-234 |
| 3 | Cust_C | 319-234 |
| 4 | Cust_D | 398-092 |
|------------------------------|
The output from the query at the moment looks like this:
-------------------------------------------------------------
| Prod_ID | Title | Price | Type_ID | Suppliers |
|------------------------------------------|----------------|
| 1 | A | 5 | Type_A | SUPP_A,SUPP_B |
| 2 | B | 7 | Type_B | SUPP_B |
| 3 | C | 3 | Type_C | SUPP_C |
| 4 | D | 3 | Type_D | SUPP_D |
|------------------------------------------|----------------|
When it should look like this surely? as Prod_ID '1' is hired out between the dates in the query
-------------------------------------------------------------
| Prod_ID | Title | Price | Type_ID | Suppliers |
|------------------------------------------|----------------|
| 2 | B | 7 | Type_B | SUPP_B |
| 3 | C | 3 | Type_C | SUPP_C |
| 4 | D | 3 | Type_D | SUPP_D |
|------------------------------------------|----------------|
If anyone can help modify the query to output as suggested i would be really grateful. Because my understanding is that it should work as written?

Answer 1

Your issue is that Prod_Id 1 is both in and out of those date ranges. So instead, use a subquery to filter out which Prod_Id are in those ranges, and exclude those.
This is a much simplified version of your query:
SELECT P.Prod_ID
FROM Products P
LEFT JOIN (
SELECT Prod_ID
FROM Hires
WHERE hire_end >= To_Date('20130121', 'yyyymmdd') AND hire_start <= To_Date('20130126', 'yyyymmdd')
) H ON P.Prod_ID = H.Prod_ID
WHERE h.prod_id IS NULL
And the SQL Fiddle.
Assuming I copied and pasted correctly, this should be your query:
SELECT products.prod_id, products.title, products.price, product_types.name,
listagg(suppliers.name, ',') WITHIN GROUP(ORDER BY suppliers.name) suppliers
FROM products
INNER JOIN product_suppliers ON products.prod_id = product_suppluer.prod_id
INNER JOIN product_types ON product_types.type_id = products.type_id
INNER JOIN suppliers ON product_suppliers.supp_id = suppliers.supp_id
LEFT JOIN (
SELECT Prod_ID
FROM Hires
WHERE hire_end >= To_Date('20130121', 'yyyymmdd') AND hire_start <= To_Date('20130126', 'yyyymmdd')
) H ON products.Prod_ID = H.Prod_ID
WHERE H.Prod_ID IS NULL
GROUP BY products.prod_id, products.title, products.price, product_types.name
Hope this helps.

Answer 2

Your left outer join will return null values when there is no match, meaning you still have a row (with no HIRE table data) when the results of this join query are Null:
LEFT OUTER JOIN hires ON hires.prod_id = products.prod_id
WHERE (hires.hire_end < to_date('21-JAN-13')
OR hires.hire_start > to_date('26-JAN-13'))
OR hires.prod_id IS NULL
Try adding a select from the hires table (eg. hire.Hire_Start) to see this happening, then switch it to an inner join as well and I think your problem will be solved.
OR add a WHERE clause on the full query with something like hire.Hire_Start is not null
EDIT
If you change your original query to:
SELECT hires.Hire_Start, products.prod_id, products.title, products.price, product_types.name,
listagg(suppliers.name, ',') WITHIN GROUP(ORDER BY suppliers.name) suppliers
FROM products
INNER JOIN product_suppliers ON products.prod_id = product_suppluer.prod_id
INNER JOIN product_types ON product_types.type_id = products.type_id
INNER JOIN suppliers ON product_suppliers.supp_id = suppliers.supp_id
LEFT OUTER JOIN hires ON hires.prod_id = products.prod_id
WHERE (hires.hire_end < to_date('21-JAN-13') OR hires.hire_start > to_date('26- JAN-13'))
OR hires.prod_id IS NULL
GROUP BY products.prod_id, products.title, products.price, product_types.name
What comes back in the Hire_Start column?
Then if you add it to the where clause do you get the expected result:
SELECT hires.Hire_Start, products.prod_id, products.title, products.price, product_types.name,
listagg(suppliers.name, ',') WITHIN GROUP(ORDER BY suppliers.name) suppliers
FROM products
INNER JOIN product_suppliers ON products.prod_id = product_suppluer.prod_id
INNER JOIN product_types ON product_types.type_id = products.type_id
INNER JOIN suppliers ON product_suppliers.supp_id = suppliers.supp_id
LEFT OUTER JOIN hires ON hires.prod_id = products.prod_id
WHERE (hires.hire_end < to_date('21-JAN-13') OR hires.hire_start > to_date('26- JAN-13'))
OR hires.prod_id IS NULL
WHERE hires.Hire_Start is not null
GROUP BY products.prod_id, products.title, products.price, product_types.name
Finally, dropping the Outer Join altogether, does this work as expected?
SELECT hires.Hire_Start, products.prod_id, products.title, products.price, product_types.name,
listagg(suppliers.name, ',') WITHIN GROUP(ORDER BY suppliers.name) suppliers
FROM products
INNER JOIN product_suppliers ON products.prod_id = product_suppluer.prod_id
INNER JOIN product_types ON product_types.type_id = products.type_id
INNER JOIN suppliers ON product_suppliers.supp_id = suppliers.supp_id
INNER JOIN hires ON hires.prod_id = products.prod_id
WHERE (hires.hire_end < to_date('21-JAN-13') OR hires.hire_start > to_date('26- JAN-13'))
GROUP BY products.prod_id, products.title, products.price, product_types.name
And note: is the OR Hires.prod_ID sopposed to indicate that if the result returns no hire information it is available, in which case you need to write the query more like the other answer provided.

Answer 3

Here is some code that may help you:
SELECT L.V_PRODUCT_ID "PROD_ID" , L.TITLE "TITLE" , L.PRICE "PRICE" , L.TYPE "TYPE" , S.NAME "SUPPLIERS"
FROM
(SELECT V_PRODUCT_ID , TITLE , PRICE , TYPE , SUPPLIER_ID FROM
((select p.prod_id v_product_id , p.title TITLE , p.price PRICE , t.type TYPE
from products p , products_types t
where p.type_id = t_type_id) A
JOIN
(SELECT PROD_ID VV_PRODUCT_ID , SUPP_ID SUPPLIER_ID
FROM PRODUCTS_SUPPLIERS) H
ON (A.V_PRODUCT_ID = H.VV_PRODUCT_ID))) L
JOIN
SUPLLIERS S
ON (L.SUPPLIER_ID = S.SUPP_ID);

Answer 4

SELECT Emp.Empid, Emp.EmpFirstName, Emp.EmpLastName, Dept.DepartmentName
FROM Employee Emp
INNER JOIN Department dept
ON Emp.Departmentid=Dept.Departmenttid