Beginning Microsoft SQL Server 2008 ... - S3 Tech Training

Chapter 5: Creating and Altering Tables
The ALTER Statement
OK, so now we have a database and a couple of nice tables — isn’t life grand? If only things always
stayed the same, but they don’t. Sometimes (actually, far more often than we would like), we get requests
to change a table rather than re-create it. Likewise, we may need to change the size, file locations, or some
other feature of our database. That’s where our ALTER statement comes in.
Much like the CREATE statement, our ALTER statement pretty much always starts out the same:
ALTER
This is totally boring so far, but it won’t stay that way. We’ll see the beginnings of issues with this statement
right away, and things will get really interesting (read: convoluted and confusing!) when we deal
with this even further in our next chapter (when we deal with constraints).
ALTER DATABASE
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Let’s get right into it by taking a look at changing our database. We’ll actually make a couple of changes
just so we can see the effects of different things and how their syntax can vary.
Perhaps the biggest trick with the ALTER statement is to remember what you already have. With that in
mind, let’s take a look again at what we already have:
EXEC sp_helpdb Accounting
Notice that I didn’t put the quotation marks in this time as I did when we used this stored proc earlier. That’s
because this system procedure, like many of them, accepts a special data type called sysname. As long as
what you pass in is a name of a valid object in the system, the quotes are optional for this data type.
So, the results should be just like they were when we created the database:
Name db_ size Owner dbid Created Status Compatibility_
level
Accounting 15.00
MB
sa 9 May 28
2000
Status=ONLINE, Updateability=READ_WRITE,
UserAccess=MULTI_USER,
Recovery=FULL,
Version=598,
Collation=SQL_Latin1_
General_CP1_CI_AS,
SQLSort-Order=52,
IsAutoCreateStatistics,
IsAutoUpdate-
Statistics,
IsFullTextEnabled
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