Stored procedure with conversion date - sql-server

Question

I have a stored procedure that takes on range of dates:
Create Procedure Search_PO
(
#usersID CHAR(10),
#poNo VARCHAR(20),
#poDateFrom Date,
#poDateTo Date,
)
As
Begin
If (#poNo = '')
Begin
Set #poNo = Null
End
If (#poDateFrom = '01/01/0001')
Begin
Set #poDateFrom = Null
End
If (#poDateTo = '01/01/0001')
Begin
Set #poDateTo = Null
End
Select * From PurchaseOrder p, Users u, Warehouse w
Where p.warehouseID = w.warehouseID
and w.usersID = u.usersID
and u.usersID = #usersID
and ((p.poNo like '%' + #poNo + '%') or #poNo Is Null)
and (p.poDate >= convert(date, #poDateFrom, 103) Or #poDateFrom Is Null)
and (p.poDate <= convert(date, #poDateTo, 103) Or #poDateTo Is Null)
End
This worked normally when I had selected dates where it was below 12(number of months), it throws me back an error of conversion from varchar into date
I believe this is due to the fact that:
Date format in SQL Server is mm/dd/yyyy
Date format in Visual Studio is dd/mm/yyyy
I tried using this code as a standalone code to check if my conversion is working:
select * from PurchaseOrder where poDate <= convert(date,'31/5/2017',103)
It does work, but when I execute my stored procedure:
exec Search_PO 'US00000001','','1/1/0001','31/5/2017'
It returns me the conversion error again. Thank you in advance for any kind of help.

Answer 1

I think the problem is in
exec Search_PO 'US00000001','','1/1/0001','31/5/2017'
You should pass date type parameter on yyyymmdd or yyyy-mm-dd format, not dd/mm/yyyy.
Change it to:
exec Search_PO 'US00000001','','1/01/01','2017/05/31'
And you don't need to convert convert(date, #poDateFrom, 103), its type is DATE already.
just
and (p.poDate >= #poDateFrom Or #poDateFrom Is Null)
and (p.poDate <= #poDateTo Or #poDateTo Is Null)

Answer 2

Can you send the dates as text variables and then make the conversion in the stored procedure? You can use SET DATEFORMAT dmy to aling SQL Server and Visual Studio date formats.
With this modification your SP would be like this:
Create Procedure Search_PO
(
#usersID CHAR(10),
#poNo VARCHAR(20),
#poDateFrom_Chr VARCHAR(10),
#poDateTo_Chr VARCHAR(10),
)
As
Begin
DECLARE #poDateFrom DATE
DECLARE #poDateTo DATE
SET DATEFORMAT dmy
SET #poDateFrom = #poDateFrom_Chr
SET #poDateTo = #poDateTo_Chr
SET DATEFORMAT mdy
If (#poNo = '')
Begin
Set #poNo = Null
End
If (#poDateFrom = '01/01/0001')
Begin
Set #poDateFrom = Null
End
If (#poDateTo = '01/01/0001')
Begin
Set #poDateTo = Null
End
Select * From PurchaseOrder p, Users u, Warehouse w
Where p.warehouseID = w.warehouseID
and w.usersID = u.usersID
and u.usersID = #usersID
and ((p.poNo like '%' + #poNo + '%') or #poNo Is Null)
and (p.poDate >= convert(date, #poDateFrom, 103) Or #poDateFrom Is Null)
and (p.poDate <= convert(date, #poDateTo, 103) Or #poDateTo Is Null)
End
Hope it helps.

Answer 3

You are currently converting your two date paramenters twice - once in the procdeure declaration (implicitly) and once in your select statement (explicitly). Your procedure is failing at the point where the #poDateFrom and #poDateTo parameters are being implicitly cast as date in the stored procedure declaration. If you're not in control of the format of the date being passed to your procedure you should change the parameter type to varchar.
i.e.
ALTER Procedure Search_PO
(
#usersID CHAR(10),
#poNo VARCHAR(20),
#poDateFrom VARCHAR(10),
#poDateTo VARCHAR(10),
)
This will avoid the implicit conversion and rely only on your explicit conversion (i.e. convert(date, #poDateFrom, 103) ) which, as you've already shown, will work for string value '31/5/2017'