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Using ADO problem

Posted on 2002-04-30
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Last Modified: 2010-05-02
I use ADO to do database manipulation(DB access2000). First I open the connection, then import records to "mytable" from a text file. Then I CLOSE this recordset. Try to query "my table" using "select * from my table". But sometimes, I got "rst.eof" is true, some times is false. The result is not consistant. I opened the table, the records are there. I am wondering if the database status is not refreshed after I import records from text file? How should I refresh it? The wierd thing is if I use "debug" to step into every process without changing code, the "rst.eof" will always "false"???

Any help will be appreicated!

Thanks!

Lucy
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Question by:llucy88
9 Comments
 
LVL 18

Expert Comment

by:bobbit31
ID: 6981198
can you post some code please?
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Expert Comment

by:HobbitHouse
ID: 6981259
try this after the import and before the query:

mytable.MoveFirst

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LVL 3

Expert Comment

by:cmgarnett
ID: 6981335
Try using BeginTrans and CommitTrans on your ADO record writing code.

Sometimes ADO seems to lag behind and using the BeginTrans and CommitTrans makes the program wait for the ADO processing to be completed.
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LVL 1

Expert Comment

by:S2
ID: 6981426
Are you closing the connection between the import and the opening of the record set, if you are that might be the problem.
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LVL 1

Expert Comment

by:magoo2
ID: 6981436
Also try adding DoEvents after closing your original recordset.
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Author Comment

by:llucy88
ID: 6981532
Too much code for me to put here.

my table.movefirst, doevents, not working.


As files importing tables are for multiple tables. I am using the "begintrans" here to utilize the "rollback" feature in case one of the file format is not right. I defined differenct DB connections for "importing" and "manipulation". Between them, I closed the importing connection. Maybe the reason is  S2's comments. I just don't understand why? Do I have to change them same connection? why sometimes the process is right?

Thanks!

Lucy
0
 
LVL 5

Expert Comment

by:rkot2000
ID: 6981534
this sample should work for you
(the source for the problem is the same)
you can find some code to flush changes to the database from client pc.

http://support.microsoft.com/default.aspx?scid=kb;en-us;Q240317

cn.Properties("Jet OLEDB:Transaction Commit Mode") = 1

SUMMARY
Because the Microsoft Jet database engine has a read cache and lazy writes, you can get duplicate values in your custom counter field if two applications add records in less time than it takes for the cache to refresh and the lazy-write mechanism to flush to disk. This article presents a method that takes these factors into account.



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Accepted Solution

by:
BBaron earned 100 total points
ID: 6982989
Hi,
just a little comment....
I had the exact same problem about a year ago when I was
importing from anouther database, using update querys. If I put a pause of say 1 sec before the requery it would be ok, if not then on the update I got duplicate error.
I fixed the problem by closing and reopening the connection to the target database. This obviously decreased efficiency drastically but seemed to work. Still dont know how to fix properly though. Glad to see some other poor fool has the same stupid problems as me ;-))

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Author Comment

by:llucy88
ID: 6983271
Thanks a lot!

fool
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