How to define a complex return type without a table? - sql

Question

I have a stored procedure with dynamic sql that I need to return an OBJECT_RESULT type. I am trying to build the complex type within visual studio through EF. The problem, I believe, is coming from the fact that the table is one of the parameters of the proc. So when EF tries to build the type and the table is null, I get the error that the selected stored proc returns no columns. I have tried setting FMTONLY off and specified the actual columns in the select statement. Any way I can achieve this? The proc:
SET FMTONLY OFF
GO
ALTER PROCEDURE [dbo].[GetFormFieldCDC2]
(
#formfieldId INT,
#C___operation INT,
#C___start_lsn binary(10),
#schemaname sysname,
#tablename sysname
)
AS
SET NOCOUNT ON;
--IF (OBJECT_ID(QUOTENAME(#schemaname) + '.' + QUOTENAME(#tablename)) IS NULL)
-- THROW 50000, 'Table not found', 0;
DECLARE #sql AS NVARCHAR(MAX) = '
SELECT [__$start_lsn]
,[__$end_lsn]
,[__$seqval]
,[__$operation]
,[__$update_mask]
,[ID]
,[LookupList]
,[LookupColumns]
,[LookupAdditionalColumns]
,[FormFieldsID]
,[DateAdded]
,[DateEdited]
,[CreatedBy]
,[EditedBy]
,[__$command_id]
FROM ' + QUOTENAME(#schemaname) + '.' + QUOTENAME(#tablename) + '
WHERE __$start_lsn = #C___start_lsn
AND __$operation = #C___operation
AND FormFieldsID = #formfieldId;
';
EXEC sp_executesql #SQL,
N' #formfieldId INT,
#C___operation INT,
#C___start_lsn binary(10)',
#formfieldId = #formfieldId,
#C___operation = #C___operation,
#C___start_lsn = #C___start_lsn;

Answer 1

Don't set FMTONLY off. That's an old hack that is no longer necessary. Instead, explicitly declare the shape of the resultset, using EXECUTE ... WITH RESULT SETS when you execute the dynamic SQL. Like this:
CREATE OR ALTER PROCEDURE [dbo].[GetFormFieldCDC2]
(
#formfieldId INT,
#C___operation INT,
#C___start_lsn binary(10),
#schemaname sysname,
#tablename sysname
)
AS
BEGIN
/*
declare #object_id int = object_id('GetFormFieldCDC2')
select * from sys.dm_exec_describe_first_result_set_for_object(#object_id,0)
*/
SET NOCOUNT ON;
--IF (OBJECT_ID(QUOTENAME(#schemaname) + '.' + QUOTENAME(#tablename)) IS NULL)
-- THROW 50000, 'Table not found', 0;
DECLARE #sql AS NVARCHAR(MAX) = '
SELECT [__$start_lsn]
,[__$end_lsn]
,[__$seqval]
,[__$operation]
,[__$update_mask]
,[ID]
,[LookupList]
,[LookupColumns]
,[LookupAdditionalColumns]
,[FormFieldsID]
,[DateAdded]
,[DateEdited]
,[CreatedBy]
,[EditedBy]
,[__$command_id]
FROM ' + QUOTENAME(#schemaname) + '.' + QUOTENAME(#tablename) + '
WHERE __$start_lsn = #C___start_lsn
AND __$operation = #C___operation
AND FormFieldsID = #formfieldId;
';
EXEC sp_executesql #SQL,
N' #formfieldId INT,
#C___operation INT,
#C___start_lsn binary(10)',
#formfieldId = #formfieldId,
#C___operation = #C___operation,
#C___start_lsn = #C___start_lsn
WITH RESULT SETS
(
(
[__$start_lsn] binary(10)
,[__$end_lsn] binary(10)
,[__$seqval] binary(10)
,[__$operation] int
,[__$update_mask] varbinary(128)
,[ID] int
,[LookupList] varchar(max)
,[LookupColumns] varchar(max)
,[LookupAdditionalColumns] varchar(max)
,[FormFieldsID] int
,[DateAdded] datetime
,[DateEdited] datetime
,[CreatedBy] varchar(200)
,[EditedBy] varchar(200)
,[__$command_id] int
)
);
END
Then
declare #object_id int = object_id('GetFormFieldCDC2')
select * from sys.dm_exec_describe_first_result_set_for_object(#object_id,0)
Will return the resultset metadata.