Nested case limit - sql

Question

I'm trying to use nested case but SQL is giving me an error on 10 limit. Below is my sql. Do you have any suggestions for me?
ALTER VIEW [dbo].[vwOpti_ChannelPreference] AS
SELECT SUB.*,
CASE WHEN PCYCResponse + JBIResponse > 1 THEN 'SF Multi'
ELSE CASE WHEN MDLResponse + SermoResponse + BioPharmResponse + MedscapeResponse + PharmaConnectResponse + THResponse
+ OtherResponse > 1 THEN 'MCM Multi'
ELSE CASE WHEN MDLResponse + SermoResponse + BioPharmResponse + MedscapeResponse + PharmaConnectResponse + THResponse
+ PCYCResponse + JBIResponse + OtherResponse > 1 THEN 'SF & MCM Multi'
ELSE CASE WHEN MDLResponse + SermoResponse + BioPharmResponse + MedscapeResponse + PharmaConnectResponse + THResponse
+ PCYCResponse + JBIResponse + OtherResponse = 0 THEN 'None'
ELSE CASE WHEN MDLResponse = 1 THEN 'MDL'
ELSE CASE WHEN SermoResponse = 1 THEN 'Sermo'
ELSE CASE WHEN BioPharmResponse = 1 THEN 'BioPharmCommunications'
ELSE CASE WHEN MedscapeResponse = 1 THEN 'Medscape'
ELSE CASE WHEN PharmaConnectResponse = 1 THEN 'PharmaConnect'
ELSE CASE WHEN THResponse = 1 THEN 'Targeted Healthcare'
ELSE CASE WHEN PCYCResponse = 1 THEN 'PCYC'
ELSE CASE WHEN JBIResponse = 1 THEN 'JBI'
ELSE CASE WHEN OtherResponse = 1 THEN 'Other'
END END END END END END END END END END END END AS ChannelPref
FROM ( SELECT CC.*,
MAX(CASE WHEN MTE.DesignVendor = 'MDL' THEN 1 ELSE 0 END) AS MDLResponse,
MAX(CASE WHEN MTE.DesignVendor = 'Sermo' THEN 1 ELSE 0 END) AS SermoResponse,
MAX(CASE WHEN MTE.DesignVendor = 'BioPharmCommunications' THEN 1 ELSE 0 END) AS BioPharmResponse,
MAX(CASE WHEN MTE.DesignVendor = 'Medscape' THEN 1 ELSE 0 END) AS MedscapeResponse,
MAX(CASE WHEN MTE.DesignVendor = 'PharmaConnect' THEN 1 ELSE 0 END) AS PharmaConnectResponse,
MAX(CASE WHEN MTE.DesignVendor = 'Targeted Healthcare' THEN 1 ELSE 0 END) AS THResponse,
MAX(CASE WHEN MTE.DesignVendor = 'PCYC' THEN 1 ELSE 0 END) AS PCYCResponse,
MAX(CASE WHEN MTE.DesignVendor = 'JBI' THEN 1 ELSE 0 END) AS JBIResponse,
MAX(CASE WHEN MTE.DesignVendor NOT IN ('MDL','Sermo', 'BioPharmCommunications', 'Medscape', 'PharmaConnect',
'Targeted Healthcare', 'PCYC', 'JBI') THEN 1 ELSE 0 END) AS OtherResponse
--SELECT DISTINCT MTE.CHANNELNAME
FROM slice_CampaignContact CC
--LEFT JOIN slice_MktgTactic MTI ON I.MktgTacticID = MTI.MktgTacticID AND I.SliceDate = MTI.SliceDate
LEFT JOIN slice_Engagements E ON CC.ContactID = E.ContactID AND CC.SliceDate = E.SliceDate
LEFT JOIN slice_MktgTactic MTE ON E.MktgTacticID = MTE.MktgTacticID AND E.SliceDate = MTE.SliceDate
GROUP BY CC.SliceDate, CC.BrandCd, CC.ContactID, CC.SyncID, CC.FirstName, CC.LastName, CC.CampaignName,
ClientSegment, ControlSegmentName) SUB

Answer 1

You don't need the ELSE CASE every time -- that is just the way CASE works -- each WHEN is only checked on when prior WHENs fail. Like this:
SELECT SUB.*,
CASE
WHEN PCYCResponse + JBIResponse > 1 THEN 'SF Multi'
WHEN MDLResponse + SermoResponse + BioPharmResponse + MedscapeResponse + PharmaConnectResponse + THResponse + OtherResponse > 1 THEN 'MCM Multi'
WHEN MDLResponse + SermoResponse + BioPharmResponse + MedscapeResponse + PharmaConnectResponse + THResponse + PCYCResponse + JBIResponse + OtherResponse > 1 THEN 'SF & MCM Multi'
WHEN MDLResponse + SermoResponse + BioPharmResponse + MedscapeResponse + PharmaConnectResponse + THResponse + PCYCResponse + JBIResponse + OtherResponse = 0 THEN 'None'
WHEN MDLResponse = 1 THEN 'MDL'
WHEN SermoResponse = 1 THEN 'Sermo'
WHEN BioPharmResponse = 1 THEN 'BioPharmCommunications'
WHEN MedscapeResponse = 1 THEN 'Medscape'
WHEN PharmaConnectResponse = 1 THEN 'PharmaConnect'
WHEN THResponse = 1 THEN 'Targeted Healthcare'
WHEN PCYCResponse = 1 THEN 'PCYC'
WHEN JBIResponse = 1 THEN 'JBI'
WHEN OtherResponse = 1 THEN 'Other'
ELSE 'Woah, nothing matched'
END AS ChannelPref
FROM ( SELECT CC.*, -- etc