SQL Join returns duplicate entries - sql

Question

Just going to start out saying that I am new to SQL and what I've written is based off of tutorials (Also I am using SQL Server 2012). The issue I am having is I am trying to take data from 4 different tables and put them into 1 table to be accessed by Access. However I keep getting duplicate results if a value is different from the rest.
The tables look like
Cell1
|LotNum|SerialNum|PassFail|
| Lot11| 1234| 1|
| Lot11| 2345| 1|
| Lot11| 3456| 1|
| Lot11| 4567| 1|
Cell2
|LotNum|SerialNum|PassFail|
| Lot11| 1234| 1|
| Lot11| 2345| 1|
| Lot11| 3456| 1|
| Lot11| 4567| 1|
Cell3
|LotNum|SerialNum|PassFail|
| Lot11| 1234| 1|
| Lot11| 2345| 1|
| Lot11| 3456| 1|
| Lot11| 4567| 1|
Cell4
|LotNum|SerialNum|PassFail|
| Lot11| 1234| 1|
| Lot11| 2345| 1|
| Lot11| 3456| 1|
| Lot11| 4567| 0|
My code is
Alter Procedure [dbo].[spSingleData](
#LotNum varchar(50)
)
AS
Truncate Table dbo.SingleSheet
Begin
Insert INTO dbo.SingleSheet (SerialNum, Cell1PF, Cell2Pf, Cell3PF, Cell4PF)
Select Distinct Cell1.SerialNum, Cell1.PF, Cell2.PF, Cell3.PF, Cell4.PF
From dbo.Cell1
Left Join Cell2 On Cell1.LotNum=Cell2.LotNum
Left Join Cell3 On Cell1.LotNum=Cell3.LotNum
Left Join Cell4 On Cell1.LotNum=Cell4.LotNum
Where Cell1.LotNum = #LotNum
Order by SerialNum
End
PassFail can be 0, 1, or NULL, however, like in the example above, if one of the PassFails is different from the rest, the resulting table returns
|1234| 1| 1| 1| 0|
|1234| 1| 1| 1| 1|
|2345| 1| 1| 1| 0|
|2345| 1| 1| 1| 1|
|3456| 1| 1| 1| 0|
|3456| 1| 1| 1| 1|
|4567| 1| 1| 1| 0|
|4567| 1| 1| 1| 1|
Am I just using the wrong Join or should I be using something else?

Answer 1

Is this what you are trying to achieve:
If so then you are missing a JOIN predicate on SerialNum and you do not need the DISTINCT
Sample Data:
IF OBJECT_ID('tempdb..#Cell1') IS NOT NULL
DROP TABLE #Cell1
CREATE TABLE #Cell1 (LotNum varchar(10),SerialNum int,PassFail bit)
INSERT INTO #Cell1
VALUES
('Lot11',1234,1),
('Lot11',2345,1),
('Lot11',3456,1),
('Lot11',4567,1)
IF OBJECT_ID('tempdb..#Cell2') IS NOT NULL
DROP TABLE #Cell2
CREATE TABLE #Cell2 (LotNum varchar(10),SerialNum int,PassFail bit)
INSERT INTO #Cell2
VALUES
('Lot11',1234,1),
('Lot11',2345,1),
('Lot11',3456,1),
('Lot11',4567,1)
IF OBJECT_ID('tempdb..#Cell3') IS NOT NULL
DROP TABLE #Cell3
CREATE TABLE #Cell3 (LotNum varchar(10),SerialNum int,PassFail bit)
INSERT INTO #Cell3
VALUES
('Lot11',1234,1),
('Lot11',2345,1),
('Lot11',3456,1),
('Lot11',4567,1)
IF OBJECT_ID('tempdb..#Cell4') IS NOT NULL
DROP TABLE #Cell4
CREATE TABLE #Cell4 (LotNum varchar(10),SerialNum int,PassFail bit)
INSERT INTO #Cell4
VALUES
('Lot11',1234,1),
('Lot11',2345,1),
('Lot11',3456,1),
('Lot11',4567,0)
Query:
SELECT #Cell1.SerialNum,
#Cell1.PassFail,
#Cell2.PassFail,
#Cell3.PassFail,
#Cell4.PassFail
FROM #Cell1
LEFT JOIN #Cell2 ON #Cell1.LotNum = #Cell2.LotNum AND #Cell1.SerialNum = #Cell2.SerialNum
LEFT JOIN #Cell3 ON #Cell1.LotNum = #Cell3.LotNum AND #Cell1.SerialNum = #Cell3.SerialNum
LEFT JOIN #Cell4 ON #Cell1.LotNum = #Cell4.LotNum AND #Cell1.SerialNum = #Cell4.SerialNum
ORDER BY SerialNum;
Results: