Meranie casu v stored procedure

DECLARE @t1 DATETIME;
DECLARE @t2 DATETIME;

declare @client_ip nvarchar(50)
set @client_ip = CONVERT(varchar(50),(select SERVERPROPERTY('client_net_address')))


SET @t1 = GETDATE();
SELECT /* query one */ 1 ;
SET @t2 = GETDATE();

INSERT        
INTO              LogCommand( Date, CommandType, Result, CardUID,  InputParam, ElapsedMS)
VALUES        (getdate(),100,0,123,@client_ip,DATEDIFF(millisecond,@t1,@t2))