从ID不在另一个表中选择

Question

I want to select all the planes that aren't belong to a certain company. I have three tables in this case: Planes , Companies , and CompanyPlanes .

Here is my query:

SELECT *
FROM planes p,
     companyplanes cp,
     companies c
WHERE c.id = ?
  AND cp.idCompany != c.id
  AND (cp.idPlane = p.id OR p.id NOT IN (SELECT idPlane FROM companyplanes)) 
ORDER BY name ASC

But this query returned nothing! what is the wrong here?

example:

| Plane |
---------
id | name
---------
1  | p1
2  | p2
3  | p3


|Company|
---------
id | name
---------
1  | c1
2  | c2

|     companyPlanes    |
------------------------
id | idCompany | idPlane
------------------------
1  |      1    |    1
2  |      1    |    2
3  |      2    |    2

if I want to get the planes that are not belong to the company c2 the result should be: p1, p3.

Answer 1

Update Answer

We can get the result in following way

1. Get all planes of the unexpected company

   SELECT idplane from CompanyPlanes WHERE idCompany = ?

2. Get all planes without those planes of the unexpected company

   SELECT * FROM Planes WHERE id NOT IN ( SELECT idplane from CompanyPlanes WHERE idCompany = ? )

You don't need to join with Company table as you already get idCompany from CompanyPlanes table.

Answer 2

The inner join requires that the query return rows from planes which have a corresponding row in companyplanes but the subselect excludes any rows which have corresponding records in companyplanes.

Assuming that you want the records from planes which don't have a record in companyplanes, then why are you also selecting from companies?

Select p.*
From planes p
Left join
  Companyplanes do
On p.id=cp.idplane
Where cp.idplane is null;

Answer 3

If I understand your question the right way, this is what you might be looking for..

select p.*
from planes p 
     join companyplanes cp on cp.idPlane=p.id
     join companies c on c.id=cp.idCompany
where c.id != ?