SQL Server Isolate Level

Format:

SET TRANSACTION ISOLATION LEVEL

    { READ UNCOMMITTED

    | READ COMMITTED

    | REPEATABLE READ

    | SNAPSHOT

    | SERIALIZABLE

    }

[ ; ]

1. READ UNCOMMITTED: can read the uncommit record in update tranaction;

2. READ COMMITTED: can not read the uncommit record in update tranaction; 

3. REPEATABLE READ: can not read the uncommit record in update tranaction AND other tranaction can not update current read record;

4. SNAPSHOT: can read the original record before the update tranaction;

5. SERIALIZABLIE: can not read the uncommit record in update tranaction AND other tranaction can not update, insert, delete current read record;