Database Reference
In-Depth Information
It does not matter how you choose to connect, but it is important to be able to recognize each method. In
this topic, we use either
(local)
or
(local)\SQL2012
for most of our examples.
Use whichever works! Unfortunately, not all options work on all computers, so you will have to figure out
which one is able to connect on your machine. For example; localhost allows Randal to connect to SSIS, but the
alias (local) does not, even though they are supposedly equivalent. And Caryn connects in a different manner
altogether, because her only installation of SQL Server is a named instance. We discuss how to handle named
instances below.
To help you understand why some connection method's work and others do not, here is an overview of the
differences:
•
Localhost
: Allows you to connect using the network protocol TCP/IP. As you may know,
this is the protocol used throughout networks today. Localhost and the IP address
127.0.0.1 are equivalent to each other. They are both associated with TCP/IP, and each
acts as an alias for your computer name. Using the name localhost to connect to your SQL
Server works most of the time, but some configurations prevent this from working on all
computers. Although there are ways to fix these issues, the easiest thing to do is try one of
the other options.
•
(Local)
: Typing in the word
(local)
with parentheses will almost always connect when
localhost does not. This name gives you access using an older protocol called NetBIOS.
Microsoft originally used NetBIOS for networking and required NetBIOS on top of TCP/
IP for many years. This requirement is no longer mandatory; however, legacy items
remain, such as your ability to use (local) as an alias for your computer. Please note that
(local) is the only computer alias that uses parentheses. This can confuse new developers
into putting parentheses around aliases like
localhost
, leaving them unable to connect
because
localhost
, with parentheses, has no significant meaning in NetBIOS or TCP/IP.
•
A period “. ”
: If, for some reason, you still cannot connect, another option is to type a
single period as a server alias. This period symbol often works when no other selections
will. It originates from an even older Microsoft protocol called
Named Pipes
. Named
Pipes allows applications to talk to each other on a Windows machine and has been used
extensively over the years.
•
Your computer name
: You can always just type in your computer name. Keep in mind
that you can also connect to BI servers on a different computer by typing in its name. For
example, let's say your company has a development server named DevServer; you could
connect to it from your desk or laptop computer using its name, DevServer.
•
Computer Name or Alias\A_Named_Instance_on_Your_Server
: This allows you to connect
to additional named instances installed on a single computer. An example of this would
be (local)\SQLExpress or DevServer\SQLTestInstall. Keep in mind that you may only have
named SQL Server instances installed on a computer. If this is the case, attempting to
connect using the computer name is not enough. You must use the computer name or an
alias such as (local) or localhost followed by the backslash “\” followed by your instance
name—with no spaces in between.
What IS Up WIth NaMeD INStaNceS?
named instances may be confusing, but they are very convenient. Here is a brief history of how and when
they were added to SQL BI servers.
When SQL Server was first introduced by Microsoft, it could be installed only once per computer. In SQL
2000, this changed, and you could install the SQL database engine multiple times on the same machine.
