How to lock down a row in a database table immediately after a particular column has been updated.

brgdotnet
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I need to somehow lock down a row in a database table immediately afer a particular column in that row has been changed. I need to lock it down in the sense that the row can be read but not updated. The lock down will only need to occur for about 2 seconds. The objective is to prevent two different people from updating the column at nearly the same time. Is there a way to do this in Sql Server?
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Have you tried setting transaction isolation? That way, no other transactions would be able to modify data that is already being modified by another transaction, but only read it. See below for an example, mabye this helps to get your result:

Try adding the TRANSACTION ISOLATION LEVEL

SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;

BEGIN TRANSACTION;

    select * from ...

    update ...

COMMIT TRANSACTION;

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Serializable is the highest isolation level used.

SERIALIZABLE Specifies the following:

Statements cannot read data that has been modified but not yet committed by other transactions.

No other transactions can modify data that has been read by the current transaction until the current transaction completes.

Other transactions cannot insert new rows with key values that would fall in the range of keys read by any statements in the current transaction until the current transaction completes.

There are, however, other levels of isolation. Check this link for more information: https://msdn.microsoft.com/en-us/library/ms173763.aspx
brgdotnetcontractor

Author

Commented:
I haven't tried anything sir. I wanted to consult with the experts before attemtping it, and doing it the wrong way. I will look into the suggestions you posted. Thanks.
Senior DBA
Most Valuable Expert 2018
Top Expert 2014
Commented:
Use HOLDLOCK (or SERIALIZABLE) hint to keep lock on that specific table's row(s) only.  Also, since 2 secs is a very long lock in SQL terms, you'll want to explicitly delay the completion of the trans to allow that time to pass.  HOLDLOCK seems more naturally understandable to me, but of course you can use SERIALIZABLE if you prefer:


BEGIN TRANSACTION;
...
UPDATE ... WITH ( HOLDLOCK ) ...
WAITFOR DELAY '00:00:02' --wait two seconds with lock in place

COMMIT TRANSACTION;
brgdotnetcontractor

Author

Commented:
Thank you.

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