Maintaining Variable After EXEC

[Chip Mayan]

Hello,

I am fairly new at stored procedures. I have created some that will
go through a table and return a start date and an end date that is
dependent upon the fiscal period you want, but I then need to use
those dates in another stored procedure to retrieve the information I
need. My stored procedure looks like this.

================================================== ====================

CREATE PROCEDURE dbo.R920ExtTotal
@MthsBack Decimal OUTPUT
AS

DECLARE @sSQL AS NVARCHAR(255), @StartDate as SMALLDATETIME, @EndDate
as SMALLDATETIME

Exec @StartDate = GetMthStart @MthsBack

Exec @EndDate = GetMthEnd @MthsBack

SET @sSQL = 'Select count(extension) as Total From r920f00 Where
([date] BETWEEN "' +
CONVERT(nvarchar, @StartDate) +
'" and "' +
CONVERT(nvarchar, @EndDate) +
'")'

Select @sSQL

EXEC (@sSQL)

Return
GO

================================================== ===============

The problem is my variables @StartDate and @EndDate do not retain
their values after the EXEC statement and revert to 01/01/1900. How
can I get around this problem?

Thanks!!!!

Chip

[Steve Jorgensen]

Variables are only available in the scope within which they are declared. If
you need to move values out of a stored procedure, you must use output
parameters for all of them. Also, why are you building dynamic SQL in your
procedure? You can use the variables directly in SQL queries - there is no
need to convert them to strings, and insert them into a SQL string.

On 6 Jan 2004 11:05:01 -0800, cm****@lesliecontrols.com (Chip Mayan) wrote:

Hello,

I am fairly new at stored procedures. I have created some that will
go through a table and return a start date and an end date that is
dependent upon the fiscal period you want, but I then need to use
those dates in another stored procedure to retrieve the information I
need. My stored procedure looks like this.

================================================= =====================

CREATE PROCEDURE dbo.R920ExtTotal
@MthsBack Decimal OUTPUT
AS

DECLARE @sSQL AS NVARCHAR(255), @StartDate as SMALLDATETIME, @EndDate
as SMALLDATETIME

Exec @StartDate = GetMthStart @MthsBack

Exec @EndDate = GetMthEnd @MthsBack

SET @sSQL = 'Select count(extension) as Total From r920f00 Where
([date] BETWEEN "' +
CONVERT(nvarchar, @StartDate) +
'" and "' +
CONVERT(nvarchar, @EndDate) +
'")'

Select @sSQL

EXEC (@sSQL)

Return
GO

================================================= ================

The problem is my variables @StartDate and @EndDate do not retain
their values after the EXEC statement and revert to 01/01/1900. How
can I get around this problem?

Thanks!!!!

Chip

[Erland Sommarskog]

Chip Mayan (cm****@lesliecontrols.com) writes:

I am fairly new at stored procedures. I have created some that will
go through a table and return a start date and an end date that is
dependent upon the fiscal period you want, but I then need to use
those dates in another stored procedure to retrieve the information I
need. My stored procedure looks like this.

================================================= =====================

CREATE PROCEDURE dbo.R920ExtTotal
@MthsBack Decimal OUTPUT
AS

DECLARE @sSQL AS NVARCHAR(255), @StartDate as SMALLDATETIME, @EndDate
as SMALLDATETIME

Exec @StartDate = GetMthStart @MthsBack

Exec @EndDate = GetMthEnd @MthsBack

SET @sSQL = 'Select count(extension) as Total From r920f00 Where
([date] BETWEEN "' +
CONVERT(nvarchar, @StartDate) +
'" and "' +
CONVERT(nvarchar, @EndDate) +
'")'

Select @sSQL

EXEC (@sSQL)

Return
GO

I'm afraid that there are a couple of errors or strange things in this
procedure.

First: there is absolutely no reason to use dynamic SQL here. Just write:

SELKCT count(extension) AS Total
FROM r920f00
WHERE [date] BETWEEN @StartDate AND @EndDate

Second: the calls to set @StartDate and @EndDate looks funny. If
GetMthStart and GetMthEnd are user-defined functions it would be alright,
but you indicated that they were stored procedures. The return value from
a stored procedure is always an integer value, so you cannot return a
date here. And I would strongly recommend you to use return values solely
for indication of success/failure (with 0 meaning success, and about
everything else meaning failure.) So you would have to make the output
parameters:

EXEC GetMthStart @MthsBack, @StartDate OUTPUT

Third: the @MthsBack parameter is declared as output, but you never assign
it any value, you only seem to use it for input.

--
Erland Sommarskog, SQL Server MVP, so****@algonet.se

Books Online for SQL Server SP3 at
http://www.microsoft.com/sql/techinf...2000/books.asp