Create View using EF Core - sql-server

Question

Following guidance in this blog post, I've added an ef core (dotnet 6) migration into which I've pasted the t-sql to create a view.
protected override void Up(MigrationBuilder migrationBuilder)
{
migrationBuilder.Sql(#"
exec('create view [dbo].[vwSpotlightExtract] as
with
exceptions as (
select id from dbo.Application
where CTaxNumber in (
select
app.CTaxNumber
from dbo.Application app
group by app.CTaxNumber
having count(*) > 1
)
union
-- duplicate bank account
select id from dbo.Application where concat(BankSortCode, ':', BankAccountNumber) in (
select concat(app.BankSortCode, ':', app.BankAccountNumber)
from dbo.Application app
where app.BankAccountNumber is not null
group by concat(app.BankSortCode, ':', app.BankAccountNumber)
having count(*) > 1
)
union
-- duplicate uprn
select id from dbo.Application where uprn in (
select app.uprn from dbo.Application app
group by app.uprn having count(*)>1
)
),
LastAppStatus as (
select app.Id, app.UTRN,
max(rh.Id) LastRebateHistoryID
from dbo.Application app
inner join dbo.RebateHistory rh on app.ID = rh.ApplicationId
where rh.ApplicationId is not null --and rh.ApplicationId not in (select ID from exceptions)
and app.RequestType = 0 -- BACS
and ISNULL(app.PaymentStopped, 0) = 0 -- Payment NOT Stopped
--and app.id not in (select id from exceptions) -- to prevent sending stuff to spotlight
group by app.Id, app.UTRN
)
select
app.UTRN [Application Number],
'Personal' [Personal or Business Bank Account? (required)], -- always Personal
REPLACE(app.BankSortCode, '-', '') [Sort code (required)],
app.BankAccountNumber [Account number (required)],
NULL [Business name (required if business)],
app.AccountPayerFirstName [First Name (required if personal)],
app.AccountPayerSurname [Surname (required if personal)],
CASE WHEN LEN(CONCAT(addr.SAO_Start_No, addr.SAO_Start_Sfx)) > 0 and LEN (CONCAT(addr.SAO_End_No, addr.SAO_End_Sfx)) > 0 then CONCAT(addr.SAO_Start_No, addr.SAO_Start_Sfx, '-', addr.SAO_End_No, addr.SAO_End_Sfx)
WHEN LEN(CONCAT(addr.SAO_Start_No, addr.SAO_Start_Sfx)) > 0 and LEN (CONCAT(addr.SAO_End_No, addr.SAO_End_Sfx)) = 0 then CONCAT(addr.SAO_Start_No, addr.SAO_Start_Sfx)
WHEN LEN(CONCAT(addr.SAO_Start_No, addr.SAO_Start_Sfx)) = 0 and LEN (CONCAT(addr.SAO_End_No, addr.SAO_End_Sfx)) > 0 then CONCAT(addr.SAO_End_No, addr.SAO_End_Sfx)
else NULL end as
[Flat number (optional)], -- secondary addressable number or name
case when LEN(addr.PAO_Desc) > 0 then addr.PAO_Desc
when LEN(addr.SAO_Desc) < 0 then addr.SAO_Desc
ELSE NULL
end as [Building name (optional)],-- primary addressable name
CASE WHEN LEN(CONCAT(addr.PAO_Start_No, addr.PAO_Start_Sfx)) > 0 and LEN (CONCAT(addr.PAO_End_No, addr.PAO_End_Sfx)) > 0 then CONCAT(addr.PAO_Start_No, addr.PAO_Start_Sfx, '-', addr.PAO_End_No, addr.PAO_End_Sfx)
WHEN LEN(CONCAT(addr.PAO_Start_No, addr.PAO_Start_Sfx)) > 0 and LEN (CONCAT(addr.PAO_End_No, addr.PAO_End_Sfx)) = 0 then CONCAT(addr.PAO_Start_No, addr.PAO_Start_Sfx)
WHEN LEN(CONCAT(addr.PAO_Start_No, addr.PAO_Start_Sfx)) = 0 and LEN (CONCAT(addr.PAO_End_No, addr.PAO_End_Sfx)) > 0 then CONCAT(addr.PAO_End_No, addr.PAO_End_Sfx)
end [Building number (optional)],
addr.Street_Name [Street name (required)],
addr.Postcode [Address postcode (required)],
case when app.AccountType = 0 then 'Single'
when app.AccountType = 1 then 'Joint'
end as [Single or Joint account type (if personal)], -- new field coming
convert(varchar, app.AccountPayerDOB, 103) [Date of birth (if personal)],
NULL [Limited or non-limited (if business)],
NULL [Company registration number (if business)]
, ec.EventName
, app.ID
from dbo.Application app
left outer join dbo.AcademyNonDDPayers nondd on app.CTaxNumber = nondd.CTaxNumber
inner join dbo.CTaxAddress addr on RIGHT('000000000000'+ISNULL(app.uprn,''),12) = addr.uprn and nondd.CTaxPropertyRef = addr.CTaxPropertyRef
inner join LastAppStatus las on app.ID = las.ID
inner join dbo.RebateHistory rh on las.LastRebateHistoryID = rh.ID
inner join dbo.EventCode ec on rh.EventCodeId = ec.ID
where ec.ID = 11')
");
}
This causes a failure in the release pipeline. If I take the content of the sql script from the deployment artefact and paste into SSMS then I see the following error:
I'm not sure why this is because the create view statement seems to be correctly wrapped with begin and end statements:

Answer 1

CREATE VIEW can’t be inside IF/BEGIN logic; it has to be the only statement in the batch. The typical workaround is to create a script like this:
IF OBJECT_ID(N'dbo.viewname', N'V') IS NULL
BEGIN
EXEC sys.sp_executesql N'CREATE VIEW dbo.viewname AS SELECT 1;';
END
GO
ALTER VIEW dbo.viewname
AS
... real view code ...
In newer versions of SQL Server, you can just do:
CREATE OR ALTER VIEW dbo.viewname
AS
... real view code ...
But that still has to live in its own batch. Meaning it can't be inside IF/BEGIN unless you use dynamic SQL for the whole view. e.g.:
IF (some condition)
BEGIN
EXEC sys.sp_executesql N'CREATE VIEW dbo.viewname
AS
... all that view code ...;';
END
Whether you'll be able to generate any of those forms from EF core, I just don't know. Sometimes we expect an ORM to do absolutely everything but, usually, it is only capable of a very small subset.
I'm not sure of the logic you're trying to get to anyway. (If a row doesn't exist in some table, create a view? That will only work once.)