SQL - Run second Query if count result = 0 - sql

Question

Both my SELECT queries work below and return values with as two separate results. What I would like to do is if the first SELECT statement returns a 0 and it will sometimes due to the nature of our work, I would like the second to run ignoring the first one that returns zero if possible. IF the first one returns a result greater than zero then I do not want the second to run.
I have been all over looking and tried different IF ELSE and such but because of the specific date/time formulas used I am thinking it may not be possible or I this may have to be re-written altogether. There is a purpose for this but I will not bore you. Thanks in advance!
Declare #StartDate as DateTime
Declare #EndDate as DateTime
Declare #TodaysDate as DateTime
Declare #Previous as DateTime
Declare #Previous2 as DateTime
set #TodaysDate = GETDATE()
set #Previous = DATEADD(day,-1,#TodaysDate)
set #Previous2 = DATEADD(day,-2,#TodaysDate)
-- SELECT Statetment one starts here
set #StartDate = cast(convert(varchar(4), datepart(yyyy, getdate())) + '-' +
convert(varchar(2), datepart(mm, #Previous)) + '-' +
convert(varchar(2), datepart(dd, #Previous)) + ' ' +
'05:00' as datetime)
set #EndDate = cast(convert(varchar(4), datepart(yyyy, getdate())) + '-' +
convert(varchar(2), datepart(mm, #Previous)) + '-' +
convert(varchar(2), datepart(dd, #Previous)) + ' ' +
'16:59' as datetime)
SELECT Count(*) as FirstShfitPrevious
FROM [TOL_PROD_DB].[dbo].[tblLOT_CTRL_Active_Component]
WHERE Close_Time_Stamp between #StartDate and #EndDate
-- Query 2 Starts, Declarations already made at beginning
set #StartDate = cast(convert(varchar(4), datepart(yyyy, getdate())) + '-' +
convert(varchar(2), datepart(mm, #Previous2)) + '-' +
convert(varchar(2), datepart(dd, #Previous2)) + ' ' +
'05:00' as datetime)
set #EndDate = cast(convert(varchar(4), datepart(yyyy, getdate())) + '-' +
convert(varchar(2), datepart(mm, #Previous2)) + '-' +
convert(varchar(2), datepart(dd, #Previous2)) + ' ' +
'16:59' as datetime)
SELECT Count(*) as FirstShfitPrevious2
FROM [TOL_PROD_DB].[dbo].[tblLOT_CTRL_Active_Component]
WHERE Close_Time_Stamp between #StartDate and #EndDate

Answer 1

You can try to store the value of your first query result in a variable and then then check the value like
declare #myVar int
SELECT #myVar = Count(*) as FirstShfitPrevious
FROM [TOL_PROD_DB].[dbo].[tblLOT_CTRL_Active_Component]
WHERE Close_Time_Stamp between #StartDate and #EndDate)
if(#myVar = 0)
//Here your second query logic
begin
set #StartDate = cast(convert(varchar(4), datepart(yyyy, getdate())) + '-' +
convert(varchar(2), datepart(mm, #Previous2)) + '-' +
convert(varchar(2), datepart(dd, #Previous2)) + ' ' +
'05:00' as datetime)
set #EndDate = cast(convert(varchar(4), datepart(yyyy, getdate())) + '-' +
convert(varchar(2), datepart(mm, #Previous2)) + '-' +
convert(varchar(2), datepart(dd, #Previous2)) + ' ' +
'16:59' as datetime)
SELECT Count(*) as FirstShfitPrevious2
FROM [TOL_PROD_DB].[dbo].[tblLOT_CTRL_Active_Component]
WHERE Close_Time_Stamp between #StartDate and #EndDate
end

Answer 2

use NOT Exists..
if NOT Exists
(Select 1 as FirstShfitPrevious--first query
FROM [TOL_PROD_DB].[dbo].[tblLOT_CTRL_Active_Component]
WHERE Close_Time_Stamp between #StartDate and #EndDate
)
Begin
SELECT Count(*) as FirstShfitPrevious2--second query
FROM [TOL_PROD_DB].[dbo].[tblLOT_CTRL_Active_Component]
WHERE Close_Time_Stamp between #StartDate and #EndDate
END
Else
Begin
--First query
End

Answer 3

or even that way:
SELECT TOP 1 Count(*) as FirstShfitPrevious2
FROM [TOL_PROD_DB].[dbo].[tblLOT_CTRL_Active_Component]
WHERE Close_Time_Stamp between #StartDate and #EndDate
GROUP BY CAST(Close_Time_Stamp AS DATE)
ORDER BY CAST(Close_Time_Stamp AS DATE) DESC
with period covering both date ranges.