Multiple procs execution using row count in sql server - sql-server

Question

I have a proc in which I need to execute 4 different query based on the condition if the result from 1st query is 0 then it should execute the 2nd query and so on
I am using the ##RowCount to find the row count and then passing the value. Here is my code:
ALTER PROCEDURE FetchingValues #StartLocation Varchar(200),#EndLocation Varchar(200)
AS
DECLARE
#Count NUMERIC
BEGIN
if ##ROWCOUNT=0
BEGIN
select DISTINCT TOP 1 t1.Train_No,Max(t1.Distance) as TotalDistance,0 as Waiting_Time
from Rail t1
where t1.Source_Station_Name Like #StartLocation+'%'
and t1.Destination_Station_Name Like #EndLocation+'%'
GROUP BY t1.Train_No
Order BY TotalDistance ASC
SET #Count= (SELECT ##ROWCOUNT)
SELECT ##ROWCOUNT
END
ELSE if #Count <> 1
BEGIN
EXEC Connection1 #StartLocation,#EndLocation
SET #Count=(SELECT ##ROWCOUNT)
SELECT ##ROWCOUNT
END
ELSE if #Count <> 1
BEGIN
EXEC Connection2 #StartLocation,#EndLocation
SET #Count=(SELECT ##ROWCOUNT)
SELECT ##ROWCOUNT
END
ELSE
BEGIN
select DISTINCT TOP 1 (t1.Train_No+','+ t2.Train_No+','+t3.Train_No+','+t4.Train_No) as TrainSeq,
Max(t1.Distance)+Max(t2.Distance)+Max(t3.Distance)+Max(t4.Distance)as TotalDistance
from Rail t1
join Rail t2 on (t2.Source_Station_Name=t1.Destination_Station_Name)
Join Rail t3 on (t3.Source_Station_Name=t2.Destination_Station_Name)
Join Rail t4 on (t4.Source_Station_Name=t3.Destination_Station_Name)
where t1.Source_Station_Name Like #StartLocation+'%'
and t2.Destination_Station_Name Like #EndLocation+'%'
Group by t1.Train_No,T2.Train_No,t3.Train_No,t4.Train_No
ORDER BY TotalDistance ASC
END
I want to execute the query by passing 2 values then I should check through all the queries and should get the output

Answer 1

If you need to suppress empty resultsets then there is only one way - insert exec into temp table and check whethere there is anything or not. If there are records - no need to run next queries, just select from #.
BEGIN
select DISTINCT TOP 1 t1.Train_No,Max(t1.Distance) as TotalDistance,0 as Waiting_Time
into #t -- <<<<<<
from Rail t1
where t1.Source_Station_Name Like #StartLocation+'%'
and t1.Destination_Station_Name Like #EndLocation+'%'
GROUP BY t1.Train_No
if not exists(select 1 from #t)
BEGIN
insert #t
EXEC Connection1 #StartLocation,#EndLocation
END
if not exists(select 1 from #t)
BEGIN
insert #t
EXEC Connection2 #StartLocation,#EndLocation
END
if not exists(select 1 from #t)
...
/* finally */
select * from #t
Order BY TotalDistance ASC
END