Query with three temp tables that cannot be combined unable to pass data between case statements (multi-part identifier error) - sql

Question

TL;DR
My query has three temp tables due to the many mitigating factors described in the below post. I do not know of a way to combine the temp tables into a single temp table in order to pass information between two case statements. Nor do I have a way to pass the information between the case statements as a SET #variable = CASE raises the "Multi-part identifier could not be bound" error. So I need a way to refactor or alter my query to allow information to be passed from one Case statement to the other.
I have a query with three temp tables running on SQL Server 2012.
The first temp table, (#HRData), holds HR information. After a SELECT that features FULL OUTER JOINS it ends with a CTE that deletes unwanted rows using:
RN = ROW_NUMBER()OVER(PARTITION BY P.LastName ORDER BY P.LastName, P.PhoneTypeID DESC)
FROM #TempPhones P
)
DELETE FROM CTE WHERE RN > 1
This SQL code goes through these steps to isolate a particular phone number for each individual that can come from many types of phone numbers due to business rules.
The second temp table (#SecondaryPhones) deals with a troublesome database architecture choice that was made a couple of decades ago. It contains phone numbers (all in a single table), but the IDs for these records are not tied to individuals. They are tied to physical addresses in an address table with address IDs. The code for this is:
SELECT H.PersonnelID, P.LastName, P.FirstName, PH.PhoneNumber, H.Addr1, H.AddrDesc, PHT.PhoneTypeDesc, PH.PhoneTypeID
INTO #SecondaryPhones
FROM Home H
INNER JOIN Personnel P ON H.PersonnelID = P.PersonnelID
INNER JOIN Phone PH ON H.HomeAddrID = PH.HomeAddrID
LEFT OUTER JOIN PhoneType PHT ON PH.PhoneTypeID = PHT.PhoneTypeID
ORDER BY H.PersonnelID, PH.PhoneNumber;
WITH FinalTable AS (
SELECT SP.PeopleID, SP.PhoneNumber, SP.LastName, SP.FirstName, SP.PhoneTypeDesc,
ROW_NUMBER() OVER (Partition BY PeopleID ORDER BY SP.LastName, SP.PhoneTypeDesc ASC) n
FROM #SecondaryPhones SP )
Due to the FULL OUTER JOINS in #HRData and the different orderings via ROW_NUMBER()OVER(PARTITION BY....) I do not know of a way to join these two temp tables that would allow me isolate the unique phone number in the first temp table and gather the phone list in the second temp table.
The third temp table takes the data from #SecondaryPhones and creates rows that contain all the phone numbers for a single individual:
SELECT a.PersonnelID, a.LastName, a.FirstName, a.PhoneNumber as Phone1, b.PhoneNumber as Phone2, c.PhoneNumber as Phone3
INTO #FinalSecondaryPhones
FROM FinalTable a
LEFT JOIN FinalTable b ON b.PeopleID=a.PeopleID AND b.n=2
LEFT JOIN FinalTable c ON c.PeopleID=b.PeopleID AND c.n=3
WHERE a.n=1
ORDER BY PersonnelID
When I make my final SELECT DISTINCT I select a number of columns from HRData and then add this code:
-- This Case statement works fine
CASE
WHEN FSP.Phone1 != HRD.PrimaryMobilePhone
THEN FSP.Phone1
ELSE
FSP.Phone2
END AS PersonalPhone,
-- See When statement for issue
CASE
WHEN (FSP.Phone2 != HRD.PrimaryMobilePhone) AND (FSP.Phone2 != --Need value of PersonalPhone from previous Case Statement here)
THEN FSP.Phone2
ELSE
FSP.Phone3
END AS AdditionalPersonalPhone
FROM #HRData HRD
LEFT OUTER JOIN #FinalSecondaryPhones FSP ON FSP.PersonnelID = HRD.PersonnelID
LEFT OUTER JOIN Dept D ON D.DeptID = HRD.DeptID
Because of the business data entry rules, database architecture, and human error amplified by a very old data entry application (written in ColdFusion 5), I am using these case statements to eliminate duplicates and need the result from the first for comparison in the second. I suspect combining these temp tables may offer a solution, but can't see how to do this. And I cannot pass a variable between the case statements due to the "Multi-part identifier could not be bound" issue. So how can I make sure the phone numbers entered in the three columns in question are unique values? All assistance offered is greatly appreciated.

Answer 1

Have you tried just dropping the whole CASE statement that defines PersonalPhone in there?
SELECT
-- This Case statement works fine
CASE
WHEN FSP.Phone1 <> HRD.PrimaryMobilePhone THEN
FSP.Phone1
ELSE
FSP.Phone2
END AS PersonalPhone
-- See When statement for issue
, CASE
WHEN (FSP.Phone2 <> HRD.PrimaryMobilePhone)
AND (FSP.Phone2 <> CASE
WHEN FSP.Phone1 <> HRD.PrimaryMobilePhone THEN
FSP.Phone1
ELSE
FSP.Phone2
END
) THEN
FSP.Phone2
ELSE
FSP.Phone3
END AS AdditionalPersonalPhone
FROM #HRData HRD
LEFT OUTER JOIN #FinalSecondaryPhones FSP ON FSP.PersonnelID = HRD.PersonnelID
LEFT OUTER JOIN Dept D ON D.DeptID = HRD.DeptID