Question

I want to write a Oracle query which will list down all id,name & file from repo1 which has a matching id in file_repo but no matching id found in repo1_status

repo1
id, name    
1,  abc 
2,  def
3,  emm
4,  xdd

file_repo
id, file
1,  a.c
2,  d.c
3,  e.c
4,  x.c

repo1_status
id, status, status_desc
1,  good,   new generated
3,  good,   new generated

So far I wrote the below query, which does not work. Any help

SELECT repo1.id, name,file
FROM repo1,file_repo,repo1_status
WHERE (repo1.id=file_repo.id and repo1.id!=repo1_status.id)

Answer 1

You could try this

 SELECT repo1.id, name,file_repo
 FROM repo1 INNER JOIN file_repo ON repo1.id = file_repo.id 
 WHERE NOT EXISTS (SELECT id FROM repo1_status WHERE repo1_status.id = repo1.id)

Here is the link about EXISTS

OR

SELECT repo1.id, name,file_repo
 FROM ((repo1 INNER JOIN file_repo ON repo1.id = file_repo.id)
      LEFT JOIN file_repo.id ON file_repo.id = repo1.id)
 WHERE file_repo.id is null

A left join like this is the same as NOT EXISTS and it might have a better performance