The MIN function requires 1 argument(s) - sql

Question

Below is the code snippet in which MIN function using. When execute below code it is giving an error.
CREATE FUNCTION [dbo].[FN_TempCalcTransportExemp]
(
#EmployeeID varchar(20),
#PayElement varchar(20),
#Month varchar(10),
#FinYear varchar(10)
)
RETURNS decimal
AS
BEGIN
DECLARE #TarnsportExemption decimal(18,2) = 0
DECLARE #TDSIsFullExemption bit
DECLARE #PermanentPhysicalDisability decimal(18,2) = 0
DECLARE #UsingComapnyCar bit
DECLARE #Conveyance decimal(18,2) = 0
DECLARE #TransYes decimal(18,2) = 0
DECLARE #TransNo decimal(18,2) = 0
DECLARE #MinConveyance decimal(18,2) = 0
DECLARE #MinTransport decimal(18,2) = 0
SELECT
#TDSIsFullExemption = TDSDetailsFullExemption,
#TransYes = TDSDetailsYes,
#TransNo = TDSDetailsNo
FROM
tbl_TDSSettingDetails
WHERE
TDSSettingsDetailID = 2
SELECT
#Conveyance = #Month
FROM
tbl_Income
WHERE
EmployeeID = #EmployeeID
AND Element = #PayElement
AND FinancialYear = #FinYear
SELECT
#UsingComapnyCar = UsingCompanyCar,
#PermanentPhysicalDisability = PermanentPhysicalDisability
FROM
tbl_Employee_TDS
WHERE
EmployeeID = #EmployeeID
AND TDSFinancialYear = #FinYear
IF (#TDSIsFullExemption = 1)
BEGIN
SET #TarnsportExemption = #Conveyance
END
ELSE
BEGIN
IF (#UsingComapnyCar = 1)
BEGIN
IF (#Conveyance = 0)
BEGIN
SET #MinConveyance = 0
END
ELSE
BEGIN
SET #MinConveyance = #Conveyance
END
IF (#PermanentPhysicalDisability = 1)
BEGIN
SET #MinTransport = #TransYes
END
ELSE
BEGIN
SET #MinTransport = #TransNo
END
SET #TarnsportExemption = MIN(#MinConveyance, #MinTransport)
END
ELSE
BEGIN
SET #TarnsportExemption = 0
END
END
RETURN #TarnsportExemption
END
Error Message:
Msg 174, Level 15, State 1, Procedure FN_TempCalcTransportExemp, Line
66
The MIN function requires 1 argument(s).

Answer 1

set #TarnsportExemption = MIN(#MinConveyance,#MinTransport) - The MIN function is not what you think it is.
You probably want to do something like this:
set #TarnsportExemption = CASE WHEN #MinConveyance < #MinTransport THEN
#MinConveyance
ELSE
#MinTransport
END
Another option is this:
SELECT #TarnsportExemption = MIN(val)
FROM
(
SELECT #MinConveyance as val
UNION ALL
SELECT #MinTransport as val
)
And one more option is to use the values clause:
SELECT #TarnsportExemption = MIN(val)
FROM (VALUES ( #MinConveyance), (#MinTransport)) AS value(val)

Answer 2

Change your min statement like below MIN. Please refer MIN (Transact-SQL)
--fROM
set #TarnsportExemption = MIN(#MinConveyance,#MinTransport)
--To
SELECT #TarnsportExemption = MIN(A) FROM (
SELECT #MinConveyance A
UNION ALL
SELECT #MinTransport
)AS AA

Answer 3

In SQL, MIN function will return you minimum value of a column from selected list; so you can use MIN only in inline queries.
e.g. Select min(Salary) from Tbl_Employee
So, in your case either you can use case when then or union all to get minimum value from two variables as:-
SET #TarnsportExemption = CASE WHEN #MinConveyance < #MinTransport THEN #MinConveyance ELSE #MinTransport END
OR
SELECT #TarnsportExemption = MIN(TEMPS.[VALUE])
FROM (
SELECT #MinConveyance AS VALUE
UNION ALL
SELECT #MinTransport AS VALUE
) AS TEMPS