Stored procedure with temporary tables, Entity Framework updating the stored procedure not working - SET FMTONLY OFF - sql

I have a stored procedure which has multiple temporary tables, when I tried importing it in Entity Framework it didn't create the complex type and I get this error:
The selected stored procedure or function returns no columns
When I googled, I found adding this piece of code SET FMTONLY OFF in the stored procedure will create the complex type in my EDMX. I was able to do it.
Everything works well in Entity Framework now after adding SET FMTONLY OFF.
Now my question is, is there a security threat by adding this piece of code to my stored procedure which contains multiple temp tables ?
Thank you.

You don't want to just SET FMTONLY OFF, as that could have unintended consequences, but you could return an empty result set of the right shape, then turn FMTONLY OFF and RETURN at the beginning of your stored procedure.
eg
if 1=0 --this will only run in FMTONLY is ON
begin
select cast(1 as decimal(12,0) a, cast('x' as nvarchar(20)) b -- . . .
set fmtonly off
return;
end
Since FMTONLY ignores control flow statements it will run the code in the begin/end. The client will get an empty resultset, then the procedure exists. You have to turn off FMTONLY or else the return will not be executed, and you will get an error with your temp tables later.
When this stored procedure is run without FMTONLY the if 1=0 will be evaluated, and that block skipped.
However switching out the stored procedure for one without temp tables when you update the EF model is a valid alternative.

Related

Check number of stored procedures from a different database

I am trying to fix a stored procedure that we have created to count number of running procedures with a certain name.
What I am trying to do is get the number of running stored procedures that match a specific title and it works fine when the Stored Procedure executing the query is in the same Database as the procedures I am trying to count as running. But I don't understand how I can count the number of running procedures matching a name running in a different Database. I assume the dbid parameter has to be used in some way, but I don't understand how.
The database I want to count in is called "ScheduledJobs" rather than MySampleDB where I have to put the stored procedure (I can't move it to the other DB for different reasons).
Any suggestions are welcome. Here is my code:
USE [MySampleDB]
GO
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER procedure [dbo].[sp_CheckRuns2]
#RowsAffected INT OUTPUT
AS
BEGIN
SELECT
object_name(st.objectid) as ProcName
FROM
sys.dm_exec_connections as qs
CROSS APPLY sys.dm_exec_sql_text(qs.most_recent_sql_handle) st
WHERE
object_name(st.objectid) is not null and OBJECT_NAME(st.objectid) like '%sp_UPDATER'
END
select #RowsAffected = ##rowcount
RETURN #RowsAffected
Just pass in dbid as an extra parameter
WHERE OBJECT_NAME(st.objectid, st.dbid) like '%sp_UPDATER'
Side note: You should remove RETURN #RowsAffected. It is not necessary, as you are anyway passing back an OUTPUT parameter. Note also that most client APIs will give the rowcount in any case.

Stored procedure with multiple 'INSERT INTO Table_Variable EXECUTE stored_procedure' statements [duplicate]

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"

Stored proc in Execute SQL Task not persisting changes to database

I have an Execute SQL Task using an Update statement that I would like to change to a stored procedure.
My stored procedure works fine in SSMS, however when I try and use the stored proc in the Execute SQL Task, the component doesn't fail, however it doesn't persist the Updated changes to the Database.
The Connection managers are solid as the Update statement works and it wouldn't even be able to call the stored proc if the Connection manager was wrong anyway.
I have tried deleting and recreating the component but that did not help. It almost seems like the query is being executed, succeeds, and then the changes are rolled back.
I would start by checking the pstream variable type.
Your stored proc expects an INT and you are passing a NUMERIC.
I am guessing that the parcing doesn't work as expected.
Try to have your SSIS variable 'USER::Pstream' as Int32 and the Sql task parameter type as LONG
i have tried the following and works for me.
CREATE TABLE dbo.TestTable(
[BucketName] NVARCHAR(250),
[DBName] NVARCHAR(250),
[Pstream] INT
)
GO
CREATE PROCEDURE dbo.UpdateBucket
#BucketName NVARCHAR(250),
#DbName NVARCHAR(250),
#PStream INT
AS
BEGIN
UPDATE dbo.TestTable
SET BucketName = #BucketName
where DBName = #DbName and Pstream = #PStream
END
GO
INSERT INTO dbo.TestTable VALUES ('A bucket', 'A database', 100)
Add a breakpoint before the task executes so that you can inspect the variables before it executes. Once your package stops at the breakpoint, use the Watch window to see what the current values are that will be used in your stored proc. I suspect that you will find they are different than expected. If you have never used Watch, this should get you going:
Watch variables during SSIS Debug

Stored Procedure returning duplicate results where as firing the sql it runs directly doesn't

We have got a stored procedure in SQL Server 2005 with a complicated bit of single select query. Recently in one environment, we noticed that for a small subset of the results returned by the stored proc, there were duplicate records. When we ran the sql query directly, we got the correct set of records without any duplicates. The stored procedure uses a lot of views and joins (inner join/left join). One theory I have is that somehow the stored procedure is using some cached execution plans as we have modified some views recently, but I don't have enough SQL expertise to be sure of that. Does any one have any idea?
Thanks for your help,
Ashish
Different results might be caused by different connection settings (e.g. ansi_nulls, arith_abort etc.).
Run sp_recompile on the stored procedure to clear the procedure cache for that stored procedure.
To clear the entire procedure cache execute
DBCC FREEPROCCACHE
Here's an example of recompiling if you want to put it in a re-usable script:
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
/****** Object: Maintenance - StoredProcedure [Sample].[SampleSearch] Script Date: 07/28/2011 14:15:15 ******/
IF (EXISTS (SELECT * FROM INFORMATION_SCHEMA.ROUTINES WHERE ROUTINE_SCHEMA = 'Sample' AND ROUTINE_NAME = 'Sampleearch'))
BEGIN
PRINT 'Marking procedure [Sample].[SampleSearch] for recompile'
EXEC sp_recompile 'Sample.SampleSearch'
PRINT 'Finished marking procedure [Sample].[SampleSearch] for recompile'
END
GO
However, if the query is returning different results, maybe turn on SQL tracing or debug the call from the code to ensure the same in and out parameters are being used in both cases.

What are the consequences of a blanket update of stored procedures to include SET NOCOUNT ON

We have introduced a new data access framework for calling SQL Stored procedures. When calling a stored procedure that returns a recordset, we've run into problems where that stored procedure also performs an update (insert/update/delete) of some sort:
Cannot change the ActiveConnection
property of a Recordset object which
has a Command object as its source.
The solution to this is to add 'SET NOCOUNT ON' to the top of the stored procedure. This works just fine, and, of course, it also has a touted performance enhancement.
We are recommending to developers that when they want to write code to call an existing stored procedure, they must also refactor the stored procedure itself to include SET NOCOUNT ON.
But, this got me into wondering, what would be the potential consequences/risks of performing a blanket update of all stored procedures to include SET NOCOUNT ON. Under what scenarios would this break an SPs functionality? (given that ##ROWCOUNT function is updated even when SET NOCOUNT is ON)
Help, as always, much appreciated.
I think the main danger would be if any of your existing processes look for and/or assume that the rowcount will be returned without explicitly querying the value of ##ROWCOUNT.
It's possible that somewhere in your code is a stored proc that gets executed, and the application waits for the return row value to know that it completed, in which case the app would hang indefinitely.