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Are records locked during update, insert and delete

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edp

ARe records locked during inserts, updates and deletes ?

I know that they are if I put them inside transactions, but are they if I don't ??

Also, what happens if the two users try to lock the same record at the same time. Is it first-come-first-serve, with the later one waiting, or is an exception thrown. If so, what exception is thrown ??

Does anyone have any information on this ???

Is it always better to place updates, deletes and inserts inside transactions ??

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Reply to this message...

Minh Truong

> ARe records locked during inserts, updates and deletes ?

"Locking" has different meanings in middle layers like ADO & ADO.NET than it
does at the SQL Server level (which is something you shouldn't have to worry
about). With ADO.NET, you can't "lock" a record & hold on to it like you can
in ADO.

[Original message clipped]

Reply to this message...

Russ McClelland

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Reply to this message...

Brian Espey

when the SDK documentation talks about optimistic
concurrency and the absence of locks, I think that's
only referring to using dataadapters with datasets
(correct me if i'm wrong). if you use command objects
to issue insert, update, or delete statements, or to
call sproc's, i'm pretty sure you end up acquiring
locks just like always.

so even if you're not in a transaction and you use a
command object to execute "update table1 set field1 =
value1", an exclusive lock is acquired on those
records where field1 = value1 (blocks if an exclusive
or any shared locks are held, and waits for the locks
to be released). the locks are released when the
update statement completes if you're not in an
explicit transaction. the select behavior of course
depends on your transaction isolation level, but if
you use the default of read committed, you'll still
see shared locks acquired and released (even with
ADO.NET I think, but please correct me if I'm wrong).

Brian

--- Minh Truong <Click here to reveal e-mail address> wrote:
[Original message clipped]

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