Effect of not specifyin GO in SQL Server stored procedure - sql-server

I would like to know whether my stored procedure will get impacted without specifying Go
Here is the code flow:
Create or replace store_proc1
As
Begin
While loop
{SQL statements repeating itself until source table record count is 0}
End
"Go"
Here I have missed Go at the end of my stored procedure.. Will it impact the performance?

GO is not a SQL statement - it's a delimiter used only in SQL Server Management Studio.
So no, omitting GO will NOT in any way affect your stored procedure's ability to run, nor it performance.

Related

SQL Server - create stored procedure that runs several stored procedures sequentially

I'm not sure if this is possible but if so, my scenario would be about as simple as they come. Assuming I have 6 stored procedures called:
dbo.SyncSources
dbo.SyncData
dbo.UpdateStatistics
dbo.TruncateSourceTable
dbo.ValidateData
dbo.SearchData
None of them require any variables to be input, they simply need to be executed in the order in which they appear above. Can I create one stored procedure that will run all of them, sequentially? Keep in mind that some of the middle ones in that list take several hours to run. Also, this is on an Azure Cloud database, so SQL Server Agent is unfortunately not an option.
You can try this
create procedure OneProcedureTorunThemAll
as
begin tran
exec dbo.SyncSources
exec dbo.SyncData
exec ...
commit
it could be nice to catch errors, verify return values, etc.

View executed sql from dynamic sql

I've inherited a complicated application that uses a lot of dynamic SQL. Many of the stored procedures construct and execute significantly different SQL statements depending on input parameters. Is there a way that I can see the executed SQL, without using SQL profiler - ideally from within SQL Server Manager Studio?
I did something more-or-less along the same lines by creating a table called 'WhatHappened' with an AutoInc BigInt as a primary key, and a big varchar(8000) field to hold the dynamically created SQL commands, and then simply wrote the dynamically created SQL into the table, and looked at it with Enterprise Manager later. I don't know if it's a great solution, but it was quick and simple and worked.
You can use PRINT statement
for exp.
IF ##OPTIONS & 512 <> 0
PRINT N'This user has SET NOCOUNT turned ON.';
ELSE
PRINT N'This user has SET NOCOUNT turned OFF.';
GO
use like
PRINT #YourDynamicSQLStatement
ref. https://msdn.microsoft.com/en-IN/library/ms176047.aspx

Possible to shadow/override a SQL Server stored procedure

Is there any built in way, in SQL Server, to override an existing stored procedure for a single transaction?
Say I have a stored procedure
prc_GetValidUsers
#param1 int
...
INSERT INTO *
........prc_GetIdFromString param3
...
...
Is it possible for a single transaction, to redefine what prc_GetIdFromString to be something else? Or is it impossible to do this?
If you are using SQL Server 2005, or later, you could use a SYNONYM to point at the correct code at run time. This would require moving the existing code to an SP with a new name - so the SYNONYM could have the name of the original SP (so that everything that referenced the original SP would not need to be changed). You'd also create another SP that performed the reduced functionality that you want. The SYNONYM could then be pointed at the SP that you want to run.

Errors: "INSERT EXEC statement cannot be nested." and "Cannot use the ROLLBACK statement within an INSERT-EXEC statement." How to solve this?

I have three stored procedures Sp1, Sp2 and Sp3.
The first one (Sp1) will execute the second one (Sp2) and save returned data into #tempTB1 and the second one will execute the third one (Sp3) and save data into #tempTB2.
If I execute the Sp2 it will work and it will return me all my data from the Sp3, but the problem is in the Sp1, when I execute it it will display this error:
INSERT EXEC statement cannot be nested
I tried to change the place of execute Sp2 and it display me another error:
Cannot use the ROLLBACK statement
within an INSERT-EXEC statement.
This is a common issue when attempting to 'bubble' up data from a chain of stored procedures. A restriction in SQL Server is you can only have one INSERT-EXEC active at a time. I recommend looking at How to Share Data Between Stored Procedures which is a very thorough article on patterns to work around this type of problem.
For example a work around could be to turn Sp3 into a Table-valued function.
This is the only "simple" way to do this in SQL Server without some giant convoluted created function or executed sql string call, both of which are terrible solutions:
create a temp table
openrowset your stored procedure data into it
EXAMPLE:
INSERT INTO #YOUR_TEMP_TABLE
SELECT * FROM OPENROWSET ('SQLOLEDB','Server=(local);TRUSTED_CONNECTION=YES;','set fmtonly off EXEC [ServerName].dbo.[StoredProcedureName] 1,2,3')
Note: You MUST use 'set fmtonly off', AND you CANNOT add dynamic sql to this either inside the openrowset call, either for the string containing your stored procedure parameters or for the table name. Thats why you have to use a temp table rather than table variables, which would have been better, as it out performs temp table in most cases.
OK, encouraged by jimhark here is an example of the old single hash table approach: -
CREATE PROCEDURE SP3 as
BEGIN
SELECT 1, 'Data1'
UNION ALL
SELECT 2, 'Data2'
END
go
CREATE PROCEDURE SP2 as
BEGIN
if exists (select * from tempdb.dbo.sysobjects o where o.xtype in ('U') and o.id = object_id(N'tempdb..#tmp1'))
INSERT INTO #tmp1
EXEC SP3
else
EXEC SP3
END
go
CREATE PROCEDURE SP1 as
BEGIN
EXEC SP2
END
GO
/*
--I want some data back from SP3
-- Just run the SP1
EXEC SP1
*/
/*
--I want some data back from SP3 into a table to do something useful
--Try run this - get an error - can't nest Execs
if exists (select * from tempdb.dbo.sysobjects o where o.xtype in ('U') and o.id = object_id(N'tempdb..#tmp1'))
DROP TABLE #tmp1
CREATE TABLE #tmp1 (ID INT, Data VARCHAR(20))
INSERT INTO #tmp1
EXEC SP1
*/
/*
--I want some data back from SP3 into a table to do something useful
--However, if we run this single hash temp table it is in scope anyway so
--no need for the exec insert
if exists (select * from tempdb.dbo.sysobjects o where o.xtype in ('U') and o.id = object_id(N'tempdb..#tmp1'))
DROP TABLE #tmp1
CREATE TABLE #tmp1 (ID INT, Data VARCHAR(20))
EXEC SP1
SELECT * FROM #tmp1
*/
My work around for this problem has always been to use the principle that single hash temp tables are in scope to any called procs. So, I have an option switch in the proc parameters (default set to off). If this is switched on, the called proc will insert the results into the temp table created in the calling proc. I think in the past I have taken it a step further and put some code in the called proc to check if the single hash table exists in scope, if it does then insert the code, otherwise return the result set. Seems to work well - best way of passing large data sets between procs.
This trick works for me.
You don't have this problem on remote server, because on remote server, the last insert command waits for the result of previous command to execute. It's not the case on same server.
Profit that situation for a workaround.
If you have the right permission to create a Linked Server, do it.
Create the same server as linked server.
in SSMS, log into your server
go to "Server Object
Right Click on "Linked Servers", then "New Linked Server"
on the dialog, give any name of your linked server : eg: THISSERVER
server type is "Other data source"
Provider : Microsoft OLE DB Provider for SQL server
Data source: your IP, it can be also just a dot (.), because it's localhost
Go to the tab "Security" and choose the 3rd one "Be made using the login's current security context"
You can edit the server options (3rd tab) if you want
Press OK, your linked server is created
now your Sql command in the SP1 is
insert into #myTempTable
exec THISSERVER.MY_DATABASE_NAME.MY_SCHEMA.SP2
Believe me, it works even you have dynamic insert in SP2
I found a work around is to convert one of the prods into a table valued function. I realize that is not always possible, and introduces its own limitations. However, I have been able to always find at least one of the procedures a good candidate for this. I like this solution, because it doesn't introduce any "hacks" to the solution.
I encountered this issue when trying to import the results of a Stored Proc into a temp table, and that Stored Proc inserted into a temp table as part of its own operation. The issue being that SQL Server does not allow the same process to write to two different temp tables at the same time.
The accepted OPENROWSET answer works fine, but I needed to avoid using any Dynamic SQL or an external OLE provider in my process, so I went a different route.
One easy workaround I found was to change the temporary table in my stored procedure to a table variable. It works exactly the same as it did with a temp table, but no longer conflicts with my other temp table insert.
Just to head off the comment I know that a few of you are about to write, warning me off Table Variables as performance killers... All I can say to you is that in 2020 it pays dividends not to be afraid of Table Variables. If this was 2008 and my Database was hosted on a server with 16GB RAM and running off 5400RPM HDDs, I might agree with you. But it's 2020 and I have an SSD array as my primary storage and hundreds of gigs of RAM. I could load my entire company's database to a table variable and still have plenty of RAM to spare.
Table Variables are back on the menu!
I recommend to read this entire article. Below is the most relevant section of that article that addresses your question:
Rollback and Error Handling is Difficult
In my articles on Error and Transaction Handling in SQL Server, I suggest that you should always have an error handler like
BEGIN CATCH
IF ##trancount > 0 ROLLBACK TRANSACTION
EXEC error_handler_sp
RETURN 55555
END CATCH
The idea is that even if you do not start a transaction in the procedure, you should always include a ROLLBACK, because if you were not able to fulfil your contract, the transaction is not valid.
Unfortunately, this does not work well with INSERT-EXEC. If the called procedure executes a ROLLBACK statement, this happens:
Msg 3915, Level 16, State 0, Procedure SalesByStore, Line 9 Cannot use the ROLLBACK statement within an INSERT-EXEC statement.
The execution of the stored procedure is aborted. If there is no CATCH handler anywhere, the entire batch is aborted, and the transaction is rolled back. If the INSERT-EXEC is inside TRY-CATCH, that CATCH handler will fire, but the transaction is doomed, that is, you must roll it back. The net effect is that the rollback is achieved as requested, but the original error message that triggered the rollback is lost. That may seem like a small thing, but it makes troubleshooting much more difficult, because when you see this error, all you know is that something went wrong, but you don't know what.
I had the same issue and concern over duplicate code in two or more sprocs. I ended up adding an additional attribute for "mode". This allowed common code to exist inside one sproc and the mode directed flow and result set of the sproc.
what about just store the output to the static table ? Like
-- SubProcedure: subProcedureName
---------------------------------
-- Save the value
DELETE lastValue_subProcedureName
INSERT INTO lastValue_subProcedureName (Value)
SELECT #Value
-- Return the value
SELECT #Value
-- Procedure
--------------------------------------------
-- get last value of subProcedureName
SELECT Value FROM lastValue_subProcedureName
its not ideal, but its so simple and you don't need to rewrite everything.
UPDATE:
the previous solution does not work well with parallel queries (async and multiuser accessing) therefore now Iam using temp tables
-- A local temporary table created in a stored procedure is dropped automatically when the stored procedure is finished.
-- The table can be referenced by any nested stored procedures executed by the stored procedure that created the table.
-- The table cannot be referenced by the process that called the stored procedure that created the table.
IF OBJECT_ID('tempdb..#lastValue_spGetData') IS NULL
CREATE TABLE #lastValue_spGetData (Value INT)
-- trigger stored procedure with special silent parameter
EXEC dbo.spGetData 1 --silent mode parameter
nested spGetData stored procedure content
-- Save the output if temporary table exists.
IF OBJECT_ID('tempdb..#lastValue_spGetData') IS NOT NULL
BEGIN
DELETE #lastValue_spGetData
INSERT INTO #lastValue_spGetData(Value)
SELECT Col1 FROM dbo.Table1
END
-- stored procedure return
IF #silentMode = 0
SELECT Col1 FROM dbo.Table1
Declare an output cursor variable to the inner sp :
#c CURSOR VARYING OUTPUT
Then declare a cursor c to the select you want to return.
Then open the cursor.
Then set the reference:
DECLARE c CURSOR LOCAL FAST_FORWARD READ_ONLY FOR
SELECT ...
OPEN c
SET #c = c
DO NOT close or reallocate.
Now call the inner sp from the outer one supplying a cursor parameter like:
exec sp_abc a,b,c,, #cOUT OUTPUT
Once the inner sp executes, your #cOUT is ready to fetch. Loop and then close and deallocate.
If you are able to use other associated technologies such as C#, I suggest using the built in SQL command with Transaction parameter.
var sqlCommand = new SqlCommand(commandText, null, transaction);
I've created a simple Console App that demonstrates this ability which can be found here:
https://github.com/hecked12/SQL-Transaction-Using-C-Sharp
In short, C# allows you to overcome this limitation where you can inspect the output of each stored procedure and use that output however you like, for example you can feed it to another stored procedure. If the output is ok, you can commit the transaction, otherwise, you can revert the changes using rollback.
On SQL Server 2008 R2, I had a mismatch in table columns that caused the Rollback error. It went away when I fixed my sqlcmd table variable populated by the insert-exec statement to match that returned by the stored proc. It was missing org_code. In a windows cmd file, it loads result of stored procedure and selects it.
set SQLTXT= declare #resets as table (org_id nvarchar(9), org_code char(4), ^
tin(char9), old_strt_dt char(10), strt_dt char(10)); ^
insert #resets exec rsp_reset; ^
select * from #resets;
sqlcmd -U user -P pass -d database -S server -Q "%SQLTXT%" -o "OrgReport.txt"

What is the difference between ; and GO in stored procedure in SQL Server?

What is the difference between ; and GO in stored procedure in SQL Server ?
Actually, if I have a stored procedure in SQL server and wanna to put t separate queries inside it which the first one just calculates number of records (count) and the second one selects some records based on some conditions, then what should I use between that two queries?
Go or ;
; just ends the statement.
GO is not a statement but a command to the server to commit the current batch to the Database. It creates a stop inside the transaction.
http://msdn.microsoft.com/en-us/library/ms188037.aspx
(Update, thanks for the comments):
GO is a statement intended for the Management studio as far as I know, maybe to other tools as well.
The semicolon separates queries, the GO command separates batches. (Also GO is not a T-SQL command, it's a command recognised by the sqlcmd and osql utilities and Management Studio.)
You can't use GO inside a stored procedure. If you would try, the definition of the procedure will end there, and the rest will be a separate batch.
A local variable has the scope of the batch, so after a GO command you can't use local variables declared before the GO command:
declare #test int
set #test = 42
GO
select #Test -- causes an error message as #Test is undefined
I know this thread is old but I thought these other uses/differences might be handy for other searches like myself regarding GO.
Anything after the GO will not wind up in your sproc because the GO will execute the CREATE/ALTER PROCEDURE command. For example, if you run this...
CREATE PROCEDURE X AS
SELECT 1 As X
GO
SELECT 2 As X
Then after running it you go back in to edit the procedure you will find that only the SELECT 1 As X is in there because the GO created the sproc and anything after it is assumed to be the next thing you are doing and not part of the sproc.
I'm surprised I haven't seen this mentioned much out there but the batch separator is not only specific to the program you are querying with but in the case of SSMS it is actually user editable! If I went into the settings and changed the batch separator from GO to XX then in my copy of SSMS, XX executes the batch not GO. So what would happen if I tried to execute a stored procedure that contained GO?
Think of GO as a way of telling SSMS to send whatever is above it to the server for execution. The server never receives the GO as that is just there to mark the end of a batch of command you want SSMS to send to the server.
If you have a scenario where you need to control execution flow in your stored procedure then you can use BEGIN TRANSACTION and COMMIT TRANSACTION for that and those are allowed in stored procedures.
GO is not a command to the server, it's the default batch separator for most of the client tools the MS supply. When the client tool encounters "GO" on a new line by itself, it sends whatever commands it has accumulated thus far to the server, and then starts over anew.
What this means is that any variables declared in one batch are not available in subsequent batches. And it also means that multi-line comments can't be placed around a "GO" command - because the server will see the first batch, and see an unterminated comment.
It marks the end of a batch in Query Analyzer and
therefore signals the end of a stored procedure definition in that batch.
As much as i know its not a part of sp.
GO isn't a TSQL command.
And ; just ends the statement.

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