Better way to check condition instead of repeated Case When

Question

This is my Tables:

[Member]: 
{ [Id], [UserId], [UserName], [Email], [Status_Id], [MemberType_Id] }

[CustomerProfile] :
{ [Id], [Member_Id], [FirstName], [LastName], [SSN], [Gender], [PostalCode],[City_Id], [Address]}


[DealerProfile]:
{ [Id], [Member_Id], [FirstName], [LastName], [SSN], [Gender], [StoreName], [PostalCode], [City_Id], [Address] }


[ManagerProfile]
{ [Id], [Member_Id], [FirstName], [LastName], [SSN], [Gender] }

[City]:
{ [Id], [Title], [Province_Id] }

So I need to create a full view of all my members and related columns, I am going to start with the following select query:

SELECT     
[ME].[Id] AS [MemberId],
[ME].[UserId],
[ME].[UserName],
[ME].[Email],
[ME].[Status_Id],
[ST].[Title] AS [Status],
[ME].[MemberType_Id],
[MT].[Title] AS [MemberType],

CASE
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Customer') THEN [CUP].[Id] 
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Dealer') THEN [DEP].[Id]
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Manager') THEN [MAP].[Id] 
    ELSE 0 END AS [Profile_Id],
CASE
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Customer') THEN [CUP].[FirstName]
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Dealer') THEN [DEP].[FirstName]
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Manager') THEN [MAP].[FirstName]
    ELSE 'Unknown' END AS [FirstName],
CASE
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Customer') THEN [CUP].[LastName]
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Dealer') THEN [DEP].[LastName]
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Manager') THEN [MAP].[LastName]
    ELSE 'Unknown' END AS [LastName],
CASE
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Customer') THEN [CUP].[SSN]
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Dealer') THEN [DEP].[SSN]
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Manager') THEN [MAP].[SSN]
    ELSE 'Unknown' END AS [SSN],
CASE
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Customer') THEN [CUP].[Address]
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Dealer') THEN [DEP].[Address]
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Manager') THEN ''
    ELSE 'Unknown' END AS [Address],
CASE
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Customer') THEN [CUP].[PostalCode]
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Dealer') THEN [DEP].[PostalCode]
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Manager') THEN ''
    ELSE 'Unknown' END AS [PostalCode],
CASE
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Customer') THEN [CUP].[Gender]
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Dealer') THEN [DEP].[Gender]
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Manager') THEN [MAP].[Gender]
    ELSE 'Unknown' END AS [Gender],
CASE
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Customer') THEN [CUP].[City_Id]
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Dealer') THEN [DEP].[City_Id]
    WHEN [ME].[MemberType_Id] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Manager') THEN 0
    ELSE 0 END AS [CityId]

FROM [Members].[Member] AS [ME]
INNER JOIN [Members].[MemberType] AS [MT] ON [ME].[MemberType_Id] = [MT].[Id]
INNER JOIN [Members].[Status] AS [ST] ON [ME].[Status_Id]=[ST].[Id]
INNER JOIN [Members].[ManagerProfile] AS [MAP] ON [ME].[Id]= [MAP].[Member_Id]
INNER JOIN [Members].[CustomerProfile] AS [CUP] ON [ME].[Id]=[CUP].[Member_Id]
INNER JOIN [Members].[DealerProfile] AS [DEP] ON [ME].[Id]=[DEP].[Member_Id];
GO

As you see there is repeated Case When to find the Member Type and decide select value from which table. Is this good idea to create a view such as my view? Is there any better way to check the Member Type? I should mention that the Id column in MemberType table can be change, so I don't want use something like this: WHEN [ME].[MemberType_Id] = 1 Then '' what is your suggestion?

Answer 1

I think this will help you

SELECT     
[ME].[Id] AS [MemberId],
[ME].[UserId],
[ME].[UserName],
[ME].[Email],
[ME].[Status_Id],
[ST].[Title] AS [Status],
[ME].[MemberType_Id],
[MT].[Title] AS [MemberType],
[X].[Id] AS [Profile_Id], 
[X].[FirstName],
[X].[LastName],
[X].[SSN],
[X].[Address],
[X].[PostalCode],
[X].[Gender],
[X].[City_Id]
FROM [Members].[Member] AS [ME]
INNER JOIN [Members].[MemberType] AS [MT] ON [ME].[MemberType_Id] = [MT].[Id]
INNER JOIN [Members].[Status] AS [ST] ON [ME].[Status_Id]=[ST].[Id]
INNER JOIN 
    (Select [Member_Id], [Id], [FirstName], [LastName], [SSN], [Address]='', [PostalCode]='', [Gender], [City_Id]=0,
        [TYPE] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Customer') 
        From [Members].[ManagerProfile] AS [MAP] Where [MAP].[Member_Id] = [ME].[Id]
    Union All
    Select [Member_Id], [Id], [FirstName], [LastName], [SSN], [Address], [PostalCode], [Gender], [City_Id], 
        [TYPE] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Manager') 
    From [Members].[CustomerProfile] AS [CUP] Where [CUP].[Member_Id] = [ME].[Id]
    Union All
    Select [Member_Id], [Id], [FirstName], [LastName], [SSN], [Address], [PostalCode], [Gender], [City_Id], 
        [TYPE] = (SELECT TOP(1) [TMT].[Id] FROM [Members].[MemberType] AS [TMT] WHERE [TMT].[Title]='Dealer') 
    From [Members].[DealerProfile] AS [DEP] Where [DEP].[Member_Id] = [ME].[Id])
     AS [X] On [ME].[Id] = [X].[Member_Id] AND [ME].[MemberType_Id] = [X].[TYPE]
 GO