SQL Server: Creating transposed table and joining with existing table - sql-server

Question

I have a set of data from table [MSPWIP].[MSPWIP].[Event] that looks like this:
| Createdby | StationName | SerialNumber |
-------------------------------------------------------
| Jay | L1.A1 | 22191321572 |
| Allan | L1.A2 | 22191321572 |
| Nathan | L2.A1 | 22191321579 |
| Jane | L2.A2 | 22191321579 |
And I have other sets of data that I have already joined in another query which is not relevant to the problem
I want to create a table separating the operator (denoted by createdby) by stations where L1.A1 means Line 1 Station 1 for example. For me at the moment, Line is not relevant
My ideal data after I restructure it should look like this
| SerialNumber | Operator1 | Operator2 |
----------------------------------------
| 22191321572 | Jay | Allan |
| 22191321579 | Nathan | Jane |
I tried using this code to Join both tables:
Query#1
Declare #Operator1 Table(
SerialNumber Varchar(255),
Operator1 Varchar(255)
)
Insert Into #Operator1 (Serialnumber, Operator1)
Select
SerialNumber,
Createdby as Operator1
From [MSPWIP].[MSPWIP].[Event]
where StationName like '%01'
Declare #Operator2 Table(
SerialNumber Varchar(255),
Operator2 Varchar(255)
)
Insert Into #Operator2 (Serialnumber, Operator2)
Select
SerialNumber,
CreatedBy as Operator2
From [MSPWIP].[MSPWIP].[Event]
where StationName like '%02'
select
a.SerialNumber,
CreatedBy,
b.Operator2
From #Operator1 a
join #Operator2 b
On a.SerialNumber = b.SerialNumber
Where a.SerialNumber In ('22191321572', '22191321574')
Then I would like to join it with that other query using the code below:
Query#2
join #Operator1 i
on a.SerialNumber = i.SerialNumber
join #Operator2 j
on a.SerialNumber = j.SerialNumber
Note that a is a different table.
However with Query#1 it only managed to show the headings and not the data, and this also caused Query#2 to also display heading and nothing else.
Just wondering if there was something wrong with Query#1 where the data failed to be inserted into the columns?
============================================
Update:
Using the answer below (with Modifications) I came up with a code like this
Query#3
SELECT Distinct*
FROM (
SELECT distinct
SerialNumber,
Case When t.StationName like '%A1' then CreatedBy End Operator1,
Case When t.StationName like '%A2' then CreatedBy End Operator2
--, Max(CASE WHEN CAST(RIGHT(t.StationName, 1) AS Varchar(255)) = 1 THEN t.CreatedBy END) Operator1
--, Max(CASE WHEN CAST(RIGHT(t.StationName, 1) AS Varchar(255)) = 2 THEN t.CreatedBy END) Operator2
FROM [MSPWIP].[MSPWIP].[Event] t
where t.CreatedDate > '2019-05-30'
Group BY SerialNumber, StationName, Createdby
) d
However my results now became staggered like so:
| SerialNumber | Operator1 | Operator2 |
----------------------------------------
| 22191321572 | Jay | NULL |
| 22191321572 | NULL | Allan |
| 22191321579 | Nathan | NULL |
| 22191321579 | NULL | Jane |
Did i do something wrong here?

Answer 1

You can save your time by doing it in one run like this :
SELECT *
FROM (
SELECT
SerialNumber
, MAX(CASE WHEN RIGHT(t.StationName, 2) = '01' THEN t.Operator END) Operator1
, MAX(CASE WHEN RIGHT(t.StationName, 2) = '02' THEN t.Operator END) Operator2
FROM [MSPWIP].[MSPWIP].[Event] t
GROUP BY SerialNumber
) d
then you just join it with the required tables.
P.S : If your station part in the StationName is not always a number, then you can use SUBSTRING(t.StationName, CHARINDEX('.', t.StationName) + 1, LEN(t.StationName)) instead of RIGHT(t.StationName, 2) to get the station part (which is after the dot).