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

Chapter 11: Writing Scripts and Batches
the parser becomes somewhat confused:
Msg 102, Level 15, State 1, Line 1
Incorrect syntax near ‘GO’.
Each Batch Is Sent to the Server Separately
Because each batch is processed independently, an error in one batch does not prevent another batch
from running. To illustrate, take a look at some code:
USE AdventureWorks2008;
DECLARE @MyVarchar varchar(50); --This DECLARE only lasts for this batch!
SELECT @MyVarchar = ‘Honey, I’’m home...’;
PRINT ‘Done with first Batch...’;
GO
PRINT @MyVarchar; --This generates an error since @MyVarchar
--isn’t declared in this batch
PRINT ‘Done with second Batch’;
GO
PRINT ‘Done with third batch’; -- Notice that this still gets executed
-- even after the error
GO
If there were any dependencies between these batches, then either everything would fail — or, at the
very least, everything after the point of error would fail — but it doesn’t. Look at the results if you run
the previous script:
Done with first Batch...
Msg 137, Level 15, State 2, Line 2
Must declare the scalar variable “@MyVarchar”.
Done with third batch
Again, each batch is completely autonomous in terms of runtime issues. Keep in mind, however, that
you can build in dependencies in the sense that one batch may try to perform work that depends on the
first batch being complete — we’ll see some of this in the next section when I talk about what can and
can’t span batches.
GO Is Not a T-SQL Command
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Thinking that GO is a T-SQL command is a common mistake. GO is a command that is only recognized by
the editing tools (Management Studio, sqlcmd). If you use a third-party tool, then it may or may not
support the GO command, but most that claim SQL Server support will.