With (nolock), (nolock), nolock differences?

Question

I know that with(nolock)they (nolock)are the same or almost the same. REF: with (nolock) or (nolock) - Is there a difference?

but what about nolock? You can use any of these in select, and the only noticeable difference that I see is to use an alias that you can write:

select * from table1 as mytable with(nolock)

or

select * from table1 as mytable (nolock)

but you cannot write:

select * from table1 as mytable nolock

PS : I do not discuss nolockgood or bad here :)

Answer 1

The difference is that you must use the syntax WITH (NOLOCK)(or WITH (<any table hint>)). Why?

• WITH . MSDN:

  WITH : Microsoft SQL Server. , .

• from table1 nolock - . :

  SELECT nolock.name FROM sys.objects nolock ORDER BY nolock.name;
  

  , nolock . .

• from table1 as mytable nolock SQL Server.

  Msg 1018, 15, 1, 12
  "nolock". , A WITH . . SQL Server Books Online .

SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED, , 15 WITH (NOLOCK), . (, RCSI, , READ UNCOMMITTED IMHO), - .

, , OP, , nolock, , :

• : NOLOCK
• (Paul White)

Answer 2

:

WITH  ( <table_hint> [ [, ]...n ] )

http://technet.microsoft.com/en-us/library/ms187373.aspx