Board index » cppbuilder » Re: Invalid Variant Operation

2003-07-03 07:52:53 AM
cppbuilder84
Wrong newsgroup. You have posted in the newsgroup for the old Borland C++
compiler but your question is about the C++ Builder compiler. Look for
newsgroups with the word 'cppbuilder' in the name. A list of newsgroups is
on Borland's newsgroups page:
info.borland.com/newsgroups
I wish I could tell you the solution but I've no idea what is wrong here :-(
. Ed

generate a MAP file., give them a new EXE copy.
when the error comes up. have them give you the
address location.
find that in the map file and a near location then you
will know what functions are failing to assign a Variant.
Rick Chronister wrote:

I have a stored procedure in SQL Server 2000 that I am calling from a D5
app.
The SP starts a transaction, updates various tables and then commits the
transaction.
When I am testing this with 2 client PC's calling this same SP at exactly
the same time, every now and again if the timimg is just right, one of the
PC's get a message saying 'Invalid Variant Operation' and the update is
rolled back. The updates on the other PC get committed fine.
This error will only ever occur in the above scenario so seems to be some
sort of contention problem.
Can anyone help me out with this?
Thanks for any advice.
Matthew
 

{smallsort}

I have a stored procedure in SQL Server 2000 that I am calling from a D5
app.
The SP starts a transaction, updates various tables and then commits the
transaction.
When I am testing this with 2 client PC's calling this same SP at exactly
the same time, every now and again if the timimg is just right, one of the
PC's get a message saying 'Invalid Variant Operation' and the update is
rolled back. The updates on the other PC get committed fine.
This error will only ever occur in the above scenario so seems to be some
sort of contention problem.
Can anyone help me out with this?
Thanks for any advice.
Matthew
 

I have a stored procedure in SQL Server 2000 that I am calling from a D5
app.
The SP starts a transaction, updates various tables and then commits the
transaction.
When I am testing this with 2 client PC's calling this same SP at exactly
the same time, every now and again if the timimg is just right, one of the
PC's get a message saying 'Invalid Variant Operation' and the update is
rolled back. The updates on the other PC get committed fine.
This error will only ever occur in the above scenario so seems to be some
sort of contention problem.
Can anyone help me out with this?
Thanks for any advice.
Matthew
 

Hi Brain,
Thanks for your help. You were correct, I was trying to access the return
parameter as an integer.
I have removed that logic and I am now receiving a message saying that a
deadlock occurred and the transaction was rolled back. Could you please help
with the best way to check for this so I could re-try the stored procedure
without the user having to know?
Regards,
Matthew
"Brian Bushay TeamB" < XXXX@XXXXX.COM >wrote in message

Matthew Pascoe wrote:
a NULL value from a field to a variable (like a string).
--
jc
Remove the -not from email
 

Hi Brian,
Many thanks, you have solved my problems yet again.
The code you suggested is working perfectly.
Regards,
Matthew
"Brian Bushay TeamB" < XXXX@XXXXX.COM >wrote in message

Hi Brian,
Just a quick question on the return paramter bing null.
I am trying to figure out how to check for a null value so I don't create an
error.
The only way I seem to be able to access the value is
'proc1.Parameters.ParamByName('@RETURN_VALUE').Value'
It won't let me use AsInteger, AsString, or the IsNull option instead of the
'Value' property?
Thanks & Regards,
Matthew
"Matthew Pascoe" < XXXX@XXXXX.COM >wrote in message

Hi Jeremy,
Thanks, you were correct. The return value from the SP was null.
Regards,
Matthew
"Jeremy Collins" < XXXX@XXXXX.COM >wrote in message

Matthew Pascoe wrote:
it's sometimes a good idea to wrap the result (for strings)
in VarToStr(), which won't raise an exception but returns
an empty string instead. It's a bit neater than wrapping
everything in
if VarIsNull(...) then
...
statements.
For integers and floats etc you can roll your own versions,
for example I have two overloaded funtions like this:
function VarToFloat(Value : Variant) : Extended;
begin
Result := VarToFloat(Value, 0);
end;
function VarToFloat(Value : Variant; Default : Extended) : Extended;
begin
if VarIsNull(Value) then
Result := Default
else
Result := Value;
end;
But you have to be careful, since a "default" value in place of
a NULL number is not always appropriate.
--
jc
Remove the -not from email
 

I use:
If VarIsNull(proc1.Parameters.ParamByName('@RETURN_VALUE').Value) then
...
just add Variants to your uses if not already there.
hth,
brian
 

Hi Brian,
Thanks, thats what I was looking for.
Sorry for the delay in replying, I have been away.
Matthew
"Brian Hollister" <bhollisterATfuturaintlDOTcom>wrote in message

Hi Brian,
Sorry for the delay in replying, I have been away. Thanks again for your
help.
I am having quite a few problems with timeouts and deadlocks.
I have been doing some reading about locking but am finding it hard to
understand exactly what will cause a lock and what does not cause a lock.
Can you suggest a good resource? (I am using SQL Server 2000 and D5 with
ADO)
A couple of other stupid questions:
1) Can a select statement cause a lock on the records that it reads?
2) I have a SP that makes updates to several tables. It seems to be able to
cause a deadlock when 2 users run it at the same time even though they would
definitely not be trying to update the same records (same tables but not
same records). What sorts of things do I need to look out for?
3) Cursors - I have read they are evil and to be avoided. However, our
application lets the user set up 'rules' that each contains steps the system
should follow when processing an order, etc. We need to load the rule and
process each step one after the other. Is there a better way than a cursor
or are cursors justified in this case?
Thanks in advance for any help.
Regards,
Matthew
"Brian Bushay TeamB" < XXXX@XXXXX.COM >wrote in message

Brian,
Thanks once again. I will implement your suggestions and see how it goes.
I do have a couple of other questions that have just popped up:
1) In D5 does setting the command timeout on the ADOConnection component
work or does it have to be done in the ADOCommand component?
2) In a SP, does a lock timeout cause the SP to exit without completing the
rest of the statements? It is my understanding that a deadlock will exit the
SP immediately, was wondering if lock timeouts are the same?
Matthew
"Brian Bushay TeamB" < XXXX@XXXXX.COM >wrote in message