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What is the use of GO in SQL Server Management Studio & Transact SQL?

SQL Server Management Studio always inserts a GO command when I create a query using the right click "Script As" menu. Why? What does GO actually do?

@ChrisF -- that's not a duplicate, though the accepted answer also answers this question. That question is about using "GO" in a transaction -- it just turns out that it's not really a SQL command at all. This question is much more general and attempts to provide a definitive answer for questions about the GO command in SSMS.
Also take a look at this link: What are batching statements good for?
Microsoft documentation: SQL Server Utilities Statements - GO: The batch preceding GO will execute the specified number of times.

S
SQLMenace

https://imgur.com/TpChF.png


gbn make it SELECT and look at what happens :-)
Thanks! However then what is the point of the GO statement? This may sound stupid but what does 'batch of code' mean? msdn says after GO the variables' lifespan expire. Sounds nothing to do with transaction commitment right? Is there any circumstances where I should keep the GO statement in my scripts?
It means that all T-SQL prior to it will execute "at once". From what I understand, it is interchangeable with a semicolon (OLEDB/Oracle). For instance if you have a large post deployment script, a GO statement between lines may help memory used in the script.
This answer doesn't really explain "what it actually does" or the why
@Andrew i Agree... i still have no clue what is batch terminator supposed to mean in this context
M
MicSim

Since Management Studio 2005 it seems that you can use GO with an int parameter, like:

INSERT INTO mytable DEFAULT VALUES
GO 10

The above will insert 10 rows into mytable. Generally speaking, GO will execute the related sql commands n times.


Simplicity is the ultimate sophistication. Leonardo Da Vinci
What do you mean by "related sql commands"? Is it the command above? All commands above? The commands above until the previous GO if there is one?
t
tvanfosson

The GO command isn't a Transact-SQL statement, but a special command recognized by several MS utilities including SQL Server Management Studio code editor.

The GO command is used to group SQL commands into batches which are sent to the server together. The commands included in the batch, that is, the set of commands since the last GO command or the start of the session, must be logically consistent. For example, you can't define a variable in one batch and then use it in another since the scope of the variable is limited to the batch in which it's defined.

For more information, see http://msdn.microsoft.com/en-us/library/ms188037.aspx.


In what situation is batching things with GO actually useful?
so if 1 statement in the batch fails, do all fails?
C
Community

GO is not a SQL keyword.

It's a batch separator used by client tools (like SSMS) to break the entire script up into batches

Answered before several times... example 1


In my defense I did look through the suggested duplicates before I submitted the question -- and your example didn't show up, nor is it really a duplicate, though the answer is applicable.
It is hard to search for "GO" here :-)
M
Mykhailo Seniutovych

Just to add to the existing answers, when you are creating views you must separate these commands into batches using go, otherwise you will get the error 'CREATE VIEW' must be the only statement in the batch. So, for example, you won't be able to execute the following sql script without go

create view MyView1 as
select Id,Name from table1
go
create view MyView2 as
select Id,Name from table1
go

select * from MyView1
select * from MyView2

Also create procedures
This is the only answer that really addresses the first part of the OP's question "...always inserts a GO command.... Why?". It seems, most of the time, out of fear. The only time it's required is when a command must be in it's own batch.
This answer is why this GO command really matters
A
Adil H. Raza

Go means, whatever SQL statements are written before it and after any earlier GO, will go to SQL server for processing.

Select * from employees;
GO    -- GO 1

update employees set empID=21 where empCode=123;
GO    -- GO 2

In the above example, statements before GO 1 will go to sql sever in a batch and then any other statements before GO 2 will go to sql server in another batch. So as we see it has separated batches.


What does batch mean? The commands are executed in sequence?
Does this mean if you don't use "GO" you could get the updated employees although the select should be executed first?
A
AeroX
Use herDatabase
GO ; 

Code says to execute the instructions above the GO marker. My default database is myDatabase, so instead of using myDatabase GO and makes current query to use herDatabase


And why shouldn't it work without "GO"? I just tested it - there's no difference. "GO" seems to be redundant for the "USE" statement.
J
Jamshaid K.

I use the GO keyword when I want a set of queries to get committed before heading on to the other queries.

One thing I can add is, when you have some variables declared before the GO command you will not be able to access those after the GO command. i.e

DECLARE @dt DateTime = GETDATE();
UPDATE MyTable SET UpdatedOn = @dt where mycondition = 'myvalue';
GO

-- Below query will raise an error saying the @dt is not declared.
UPDATE MySecondTable SET UpdatedOn = @dt where mycondition = 'myvalue'; -- Must declare the scalar variable "@dt".
GO

Update

I see, people requesting when to use the Go command, so I thought, I should add why I use the Go command in my queries.

When I have huge updates in the tables and I usually run these updates while going off from work (which means, I wouldn't be monitoring the queries), since it is convenient to come the next day and find the tables ready for other operations.

I use Go command when I need to run long operations and want to separate the queries and complete part of the transactions such as:

-- First Query
Update MyBigTable SET somecol1='someval1' where somecol2='someval2'
GO
-- Second Query
Update MyBigTable1 SET somecol1='someval1' where somecol2='someval2'
GO
-- Third Query
Update MyBigTable3 SET somecol1='someval1' where somecol2='someval2'

Executing above queries will individually commit the modifications without resulting in huge roll-back logs formation. Plus if something fails on third query, you know first 2 queries were properly executed and nothing would be rolled-back. So you do not need to spend more time updating/deleting the records again for the previously executed queries.


so far the only answer that make sense. Thank you!
T
Thomas Oatman

One usage that I haven't seen listed is Error Resilience. Since only the commands between two GOs are run at a time, that means a compile error in one command can be separated from others. Normally any compile errors in a batch cause the entire thing to not be executed.

exec do.Something
GO
sel from table
print 'here'
GO
print 'there'

In above, 'here' will not be printed because of the error in the 'sel' statement.

Now, adding a GO in the middle:

exec do.Something
GO
sel from table
GO
print 'here'
GO
print 'there'

You get an error for 'sel' as before, but 'here' does get output.