ABout SELECT Syntax?

Hi,everyone.

Today I met with a interesting problem. According to Microsoft SQL SERVER 2005 BOOKS ONLINE, there is following SELECT Syntax:

(1) SELECT @local_variable (Transact-SQL)

For example:

DECLARE @i int
SELECt @i=100

(2) SELECt QUERY statement:

SELECT [ ALL | DISTINCT ]
[ TOP expression [ PERCENT ] [ WITH TIES ] ]
<select_list>
<select_list> ::=
.....

For example,

[AdventureWorks]
SELECT * FROM DatabaseLog


To my surprise, in the given project, I met this kind of SELECT statement,

DECLARE @w_type varchar(10), @i varchar(30)
SELECT @i='3'
SELECT @w_type='OLTPNORMAL' WHERE @i IN ('0','1','2','3','4','5','9',)
SELECT @w_type

The result is:

OLTPNORMAL

However, I have not met with the kind of SELECT statement before. Please give me some advice. Thank you in advance.