I want to use an alias for the following SQL query in SQL Server:

```
      a.client_id, a.name, b.address_line_1, a.address_id, a.contact_id
    , b.address_id, c.email, c.mobile_number, c.telephone_number, c.contact_id
    , c.contact_first_name 
 from client a, address b, contact c 
where a.address_id = b.address_id and a.contact_id = c.contact_id 

```

I tried this but am getting an exception

```
SELECT a.client_id AS a.ClientId
    ,a.NAME AS a.NAME
    ,a.address_id AS a AddressId
    ,a.contact_id AS a.ContactId
    ,b.address_line_1 AS b.AddressLine1
    ,b.address_id AS b.AddressId
    ,c.email AS c.Email
    ,c.mobile_number AS c.MobileNumber
    ,c.telephone_number AS c.TelephoneNumber
    ,c.contact_id AS c.ContactId
    ,c.contact_first_name AS c.ContactFirstName
FROM client a
    ,address b
    ,contact c
WHERE a.address_id AS a.AddressId = b.address_id AS b.AddressId
    AND a.contact_id AS a.ClientId = c.contact_id AS c.ClientId

```