Pass Table as parameter to function - sql

Question

I have a temp table which contains data needed in selection, but I can't join in to main select statement because it contains too many rows, and grouping is not good enough. So I decided to use values directly from my temp table in the selection, and it works fine. But since I need to add selection from temp table 50 times as sub queries in that main selection, I was considering to move it to function, as is nicer to call a function 50 times than sub queries.
My question is how to pass values from that table to function? Function will be also supplied with other parameters needed for extraction exact value from that table. I know I can't pass temp table as a parameter, but what about table variable? I don't care if I use temp table or a table variable..
Firstly I wrote a function containing the select statement same as for temp table, and it works but too slow. So if I could pass table results to a function, it will speed up the process..
My function now look like this:
ALTER FUNCTION [document].[GetPersonPremium]
(
-- Add the parameters for the function here
#DocumentId bigint,
#PersonId bigint,
#PeriodId int,
#PersonRole nvarchar(20)
)
RETURNS DECIMAL (18,2)
AS
BEGIN
-- Declare the return variable here
DECLARE #premiumSum decimal (18,2)
-- Add the T-SQL statements to compute the return value here
set #premiumSum =
(select top 1 pt.Premium from document.Document d
inner join document.Person p on p.DocumentCalculationLayerID = dcl.DocumentCalculationLayerID
inner join document.PersonTasks pt on pt.PersonId = p.PersonId
inner join document.PersonCalculationHelper pch on pch.PersonTaskId = pt.PersonTaskId
inner join document.PersonTaskCalculationHelper ptch on ptch.PersonId = p.PersonId
inner join document.PersonMarkTypes pmt on pmt.ConcernMarkTypeID = ptch.ConcernMarkTypeId
where dcl.DocumentID = #DocumentId and p.PersonId = #PersonId and pch.PeriodId = #PeriodId and pmt.Name = #PersonRole)
-- Return the result of the function
RETURN #premiumSum
END
And I would like to use it from stored procedure like this:
...
Engineer = Coalesce(document.GetPersonPremium(#DocumentId, p.PersonID, 65, 'Intern'), 0.00),
...
Any suggestion?

Answer 1

The answer is for those who come to this page with same or similar problem.
I created a table type:
CREATE TYPE PremiumTableType AS TABLE
(
PersonId bigint,
PeriodId int,
PersonRole nvarchar(20),
)
Included it in function:
ALTER FUNCTION [document].[GetPersonPremium]
(
-- Add the parameters for the function here
#DocumentId bigint,
#PersonId bigint,
#PeriodId int,
#PersonRole nvarchar(20),
#PremiumTableType PremiumTableType readonly
)
RETURNS DECIMAL (18,2)
AS
BEGIN
-- Declare the return variable here
DECLARE #premiumSum decimal (18,2)
-- Add the T-SQL statements to compute the return value here
set #premiumSum = (select p.Premium from #PremiumType p where p.PersonId = #PersonId and p.PeriodId = #PeriodId and p.PersonRole = #PersonRole)
-- Return the result of the function
RETURN #premiumSum
END
In SP declared table type variable
Declare #PremiumTableType PremiumTableType
Inserted data from my temp table
Insert into #PremiumTableType (PersonID, PeriodId, ConcernRole, PersonPremium)
Select p.PersonID, ...
And called function from SP like
document.GetPersonPremium(#DocumentID, p.PersonID, pt.PeriodID, 'Intern', #PremiumTableType)