Merge two SQL script use if condition in Select query

Question

I have 2 script as following:

First one:

SELECT [Fm].[Id], [Sdp].[FirstName], [Sdp].[LastName], [Sdp].[SSN],
[Sdp].[StoreName], [Sdp].[PostalCode], [Fc].[Id], [Sdp].[Address]
FROM [SRM].[SiteMembers].[DProfile] AS [Sdp]
INNER JOIN [SRM].[SiteMembers].[Member] AS [Sm]
ON [Sdp].[Member_Id] = [Sm].[Id]
INNER JOIN [FRM].[Members].[Member] AS [Fm]
ON [Sm].[UserId] = [Fm].[UserId]
INNER JOIN [SRM].[General].[City] AS [Sc]
ON [Sdp].[City_Id]=[Sc].[Id]
INNER JOIN [FRM].[General].[City] AS [Fc]
ON [Fc].[Title]=[Sc].[Title] 
COLLATE SQL_Latin1_General_CP1_CI_AS
WHERE ISNUMERIC([Sdp].[PostalCode])=1;

And Second one:

SELECT [Fm].[Id], [Sdp].[FirstName], [Sdp].[LastName], [Sdp].[SSN],
[Sdp].[StoreName], 0, [Fc].[Id], [Sdp].[Address]
FROM [SRM].[SiteMembers].[DProfile] AS [Sdp]
INNER JOIN [SRM].[SiteMembers].[Member] AS [Sm]
ON [Sdp].[Member_Id] = [Sm].[Id]
INNER JOIN [FRM].[Members].[Member] AS [Fm]
ON [Sm].[UserId] = [Fm].[UserId]
INNER JOIN [SRM].[General].[City] AS [Sc]
ON [Sdp].[City_Id]=[Sc].[Id]
INNER JOIN [FRM].[General].[City] AS [Fc]
ON [Fc].[Title]=[Sc].[Title] 
COLLATE SQL_Latin1_General_CP1_CI_AS
WHERE ISNUMERIC([Sdp].[PostalCode])=0;

The difference between this 2 script is that the first one select columns with numeric postal code and second one select 0 for the non numeric postal code so how can I merge this 2 script together in one script, I am not talking about Union, I am interesting to use some condition in select query for non numeric postal code select 0. Does any one have any idea?

Answer 1

I would skip the where statement and create one column for the Numeric postal code and one for the other one. Like this:

SELECT 
    [Fm].[Id], 
    [Sdp].[FirstName], 
    [Sdp].[LastName], 
    [Sdp].[SSN],
    [Sdp].[StoreName], 
    (
        CASE WHEN ISNUMERIC([Sdp].[PostalCode])=1
            THEN 0
            ELSE NULL
        END
    ) AS NumericPostalCode,
    (
        CASE WHEN ISNUMERIC([Sdp].[PostalCode])=0
            THEN [Sdp].[PostalCode]
            ELSE NULL
        END
    ) AS PostalCode,
    [Fc].[Id], 
    [Sdp].[Address]
FROM 
    [SRM].[SiteMembers].[DProfile] AS [Sdp]
INNER JOIN [SRM].[SiteMembers].[Member] AS [Sm]
    ON [Sdp].[Member_Id] = [Sm].[Id]
INNER JOIN [FRM].[Members].[Member] AS [Fm]
    ON [Sm].[UserId] = [Fm].[UserId]
INNER JOIN [SRM].[General].[City] AS [Sc]
    ON [Sdp].[City_Id]=[Sc].[Id]
INNER JOIN [FRM].[General].[City] AS [Fc]
    ON [Fc].[Title]=[Sc].[Title] 
    COLLATE SQL_Latin1_General_CP1_CI_AS´

Edit 1

I know that this will result in two columns. But you can not have to data types in one column. But I think that you can do it something like this as well.

SELECT 
    [Fm].[Id], 
    [Sdp].[FirstName], 
    [Sdp].[LastName], 
    [Sdp].[SSN],
    [Sdp].[StoreName],
    (
        CASE WHEN ISNUMERIC([Sdp].[PostalCode])=0
            THEN [Sdp].[PostalCode]
            ELSE '0'
        END
    ) AS PostalCode,
    [Fc].[Id], 
    [Sdp].[Address]

This will work becuase the numeric one are '0' as a varchar.

Edit 2

You can also do it like this:

SELECT CAST('asdasd' AS sql_variant)
UNION ALL
SELECT CAST(0 AS sql_variant)

But this is a dirty solution for this problem. The sql_variant is a database object. So my conclusion is: Use to column if you what to have different data types. If the values can be the same data type use the same column. Do not use sql_variant to solve problems like this. You will pay a high price in maintaining the code.

Hope this help.