How to join three tables with a NOT IN CLAUSE - sql

Question

Scenario ... A STORE gets a LIST. The 'LIST' basically is a collection of SKUs that the store stocks that needs to be counted.
When a store starts counting the SKUs from a given List assigned to it, the information is saved in another table called 'StoreCycles' which records the ListId, StoreName and the Dates the counting started and completed.
These are my tables.
Table 1. Table with 'Lists' which have a primary key 'ListId'
ListId ListName
1 abc
2 def
3 ghi
Table 2. 'Stores' -- Each list from the above table ('Lists' Table) is assigned to one or more stores.
The ListId in the 'Stores' Table is the primary key of the 'Lists' tabel. The Listid and LineId together make up the foreign key.
ListId LineId StoreName
1 1 StoreA
1 2 StoreD
2 1 StoreB
2 2 StoreC
2 3 StoreA
3 1 StoreA
Table 3. 'StoreCycles' -- that saves when the list assigned to a store was started counting and when it was completed.
ListId StoreName StartDate CompleteDate
1 StoreA 2016-7-22 2016-7-22
2 StoreA 2016-7-22
2 StoreC 2016-7-22
At any time I want to pull up those list names that have not been completed , i.e they have a null complete date.
This is my query:
Select T0.ListId,
T0.ListNaame ,
T2.StartDate
From Lists T0
JOIN Stores T1 On T0.ListId = T1.ListId
LEFT JOIN StoreCycles T2 ON T0.ListId = T2.ListId
WHERE T1.StoreName = 'StoreA'
AND T0.ListId NOT IN (SELECT ListId FROM StoreCycles WHERE CompleteDate IS NOT NULL)
RESULT SHOULD BE >>
ListId ListName StartDate
2 def 2016-7-22
3 ghi NULL
BUT The result that I get is this
ListId ListName StartDate
2 def NULL
2 def NULL
3 ghi NULL

Answer 1

Just passing by and dumping SQL.
Go on, nothing to see.
There is no bug hunt going on here.
declare #Lists table (ListId int primary key, ListName varchar(20));
insert into #lists values (1,'abc'),(2,'def'),(3,'ghi');
declare #Stores table (ListId int, LineId int, StoreName varchar(20));
insert into #Stores values
(1,1,'StoreA'),
(1,2,'StoreD'),
(2,1,'StoreB'),
(2,2,'StoreC'),
(2,3,'StoreA'),
(3,1,'StoreA');
declare #StoreCycles table (ListId int, StoreName varchar(20), StartDate date, CompleteDate date);
insert into #StoreCycles values
(1,'StoreA','2016-7-22','2016-7-22'),
(2,'StoreA','2016-7-22',null),
(2,'StoreC','2016-7-22',null);
SELECT
L.ListId,
L.ListName,
SC.StartDate
FROM #Stores S
JOIN #Lists L On (S.ListId = L.ListId)
LEFT JOIN #StoreCycles SC ON (S.ListId = SC.ListId AND S.StoreName = SC.StoreName)
WHERE S.StoreName = 'StoreA'
AND SC.CompleteDate IS NULL;

Answer 2

Select
l.ListId
,l.ListNaame
,sc.StartDate
From
Lists l
JOIN Stores s
ON l.ListId = s.ListId
AND s.StoreName = 'StoreA'
LEFT JOIN StoreCycles sc
ON s.ListId = sc.ListId
AND s.LineId = sc.LineId
WHERE
sc.CompleteDate IS NULL
You are already doing joins if you build them correctly you will not need a select or not in in your where clause. Also your relationship for StoreCycles seems to be wrong because you are trying to go straight from Lists to StoreCycles but Stores is the intermediary table.
Also just a thought why not use table aliases that will help you know what table you are referring to rather than t0, t1, t2 such as l, s, sc....

Answer 3

Maybe another way to look at it is to return all rows where either the StartDate is NULL (no records) or the CompleteDate is NULL (incomplete records). Also, if the foreign key is using 2 columns you probably want to use both columns in the JOIN.
SELECT T0.ListId,
T0.ListName,
T2.StartDate
FROM Lists T0
JOIN Stores T1
ON T1.ListId = T0.ListId
LEFT JOIN StoreCycles T2
ON T2.ListId = T1.ListId
AND T2.LineId = T1.LineId
WHERE T1.StoreName = 'StoreA'
AND (T2.CompleteDate IS NULL OR T2.StartDate IS NULL)