Invalid Data for Numeric when EXEC returns empty row

Hi, whenever the underlying query being called by EXEC in the following
has an empty result set I get the following error -- Invalid Data for
'Numeric' when EXEC returns empty row. However if I call the query
without using REPLACE (which I'm forced to do, because openquery does
not allow variables), I get just an empty result set. Whenever the
underlying query returns a non-empty result set, the code works without
error (regardless of wether there are nulls in the numeric column).

set @.switch ='5707550'
set @.start_date = '01-JAN-2006'
set @.end_date = '27-JAN-2006'
set @.month = 1
set @.year = 2006

set @.sql_str='
SELECT * FROM
(select MSC_KEY,
to_char(trunc(TSTAMP), ''yyyy-Mon-dd'') as "Timestamp",
ROUND( NVL(SUM(SUNRGMMSCBHCP1.XASUTIL),0) / DECODE (
NVL(SUM(SUNRGMMSCBHCP1.XASNXFR),0),0,NULL,NVL(SUM( SUNRGMMSCBHCP1.XASNXFR),0)
), 5)
as "PER_CPU_UTIL"
FROM NOR_GSM_COMPOSITE_MSC1_BHCPP SUNRGMMSCBHCP1,mscs_view v
WHERE SUNRGMMSCBHCP1.gsm_msc_key = v.msc_key and v.MSC_KEY in (' +
@.switch + ')
and SUNRGMMSCBHCP1.TSTAMP between to_date(''' + @.start_date + '
00:00:00'', ''DD-MON-YYYY HH24:MI:SS'') and
to_date(''' + @.end_date + ' 23:59:00'', ''DD-MON-YYYY
HH24:MI:SS'')

group by MSC_KEY, trunc(tstamp)
)
WHERE rownum < 10000'

SET @.sql_str = N'select * from OPENQUERY(VISION, ''' +
REPLACE(@.sql_str, '''', ''') + ''')'

EXEC (@.sql_str);

Is there anyway to prevent this error?

Thanks,

CrazyCrazy Cat wrote:
> Hi, whenever the underlying query being called by EXEC in the following
> has an empty result set I get the following error -- Invalid Data for
> 'Numeric' when EXEC returns empty row. However if I call the query
> without using REPLACE (which I'm forced to do, because openquery does
> not allow variables), I get just an empty result set. Whenever the
> underlying query returns a non-empty result set, the code works without
> error (regardless of wether there are nulls in the numeric column).

code deleted to save space ...

> Is there anyway to prevent this error?
> Thanks,
> Crazy

Found the problem -- apparently one of the keys was of type numeric and
I wasn't converting it to varchar before selecting it -- funny it
worked when the result set was non-empty.

Thanks,

Crazy

Invalid attempt to read when no data is present using SQLdatareader

I'm trying to determine if the record is NULL/empty or is valid from the datareader.

objReader = strCMD.ExecuteReader
objReader.Read()
if objReader.IsDBNull(0) = true then...

If NULL/Empty, display no records found. If records are found, display "1 or more records have been found". I keep getting the error "Invalid attempt to read when no data is present". I'm not sure what I am doing wrong here.Do While objReader.Read()
' your code.
Loop|||Use the HasRows property of a DataReader:

objReader = strCMD.ExecuteReader
If objReader.HasRows() Then
' Display 1 or more rows found
Else
' Display no rows found
End If

The reason your code was failing was because the "objReader.Read()" line attempts to access the next element in the DataReader, and so if it's empty then it becomes an invalid access, like trying to access one more index past the end of an array. If all you need is whether or not the DataReader contains any information, then HasRows is your easiest bet.|||And if what you need to do is access the info datareader contains, and are getting this error, and have a do while loop, what's the next thing to try?|||Look at why the SQL isn't returning anything!