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SQL 2005 Transcation : is .net transaction default to read commited?is this why can't read from table where insert is done until commit?

Posted on 2013-05-30
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Last Modified: 2013-06-01
I set up a .net transcation where I inserted into Table1
then Updated Table2, then commited.

Immediately after the insert was done into Table1 (before the commit), I could not read from Table1 - it was locked for reading any record until commit/rollback.

Is this because the default .net isolation level is "READ COMMITTED"?
Will READ COMMITTED cause this behaviour?

Now because of this I did the transaction in a SQL Stored Proc.
The default behaviour is different here - I can read after the Insert , and before the commit.
What is the default isolation level then for SQL Server 2005? Same/Different than .net? Can anyone comment on this please?

E.g.
 USE AdventureWorks
 BEGIN TRAN
Insert into Person.Address(AddressLine1,City,StateProvinceID,PostalCode,rowguid,ModifiedDate¿¿) select '1973 Napa Ct.','Bothell',79,'98011','9AADCB0D-36CF-483F-84D8-585C2D4EC6E3',getdate()

select * from Person.Address

ROLLBACK
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Question by:jxharding
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Accepted Solution

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Marten Rune earned 500 total points
ID: 39210135
This is why. Either use isolation level read uncommitted, or use the hint in the Querys: With NOLOCK
As select * from table tblMyTable WITH (NOLOCK) where bla bla.
There is also the option to alter database set snapshot isolation mode on, then you can use the snapshot isolation, wich basically prevents locks by keeping a snapshot of the data so it Always presents transactionally consistent data to the Querys.

Ragards Marten
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Author Closing Comment

by:jxharding
ID: 39212803
Thanks, I can't figure out yet why, even though I did not indicate in the SQL Server Proc any change to the default isolation level (read committed) - I still can read from the table before I commit. After I rollback then, the rows which I just viewed are gone.

Is there a way to, in the middle of a transaction, view the isolation level perhaps? I dont think one can set the default isolation level on a DB? Yet somehow this happens without setting the isolation level to read uncommitted
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