What is the default transaction isolation level for SQL Server with ADO.NET?

Jonathan Allen picture Jonathan Allen · Apr 4, 2012 · Viewed 53.9k times · Source

What is the default transaction isolation level for SQL Server with ADO.NET? I am using a default installation of SQL Server and just the normal System.Data.SqlClient classes.

Answer

hkf picture hkf · Apr 4, 2012

READ COMMITTED is the default isolation level for the Microsoft SQL Server Database Engine.

Source:

Here is how it compares to other isolation levels:

The MSDN documentation for SqlConnection.BeginTransaction() also states Read committed

... To reset the isolation level to the default (READ COMMITTED) ...