Why can't INSERT EXEC Stored procedures be nested? - sql-server-2005

I found a pretty good article detailing how to go about passing table data around and it mentions that the INSERT EXEC style table data sharing (http://www.sommarskog.se/share_data.html#INSERTEXEC) has the drawback of not being allowed to be nested?
In other words [in SQL Server 2005 at least], in the pseudocode below PROC1's INSERT EXEC would error out at runtime. I was wondering if anyone knows why this is.
CREATE PROC1
AS
--Fill table variable with data from somewhere
INSERT INTO #tbl EXECUTE spI_Return_Data
-- Do some stuff to the data
-- 'Return' it
SELECT * FROM #tbl
GO
CREATE PROC2
AS
--Fill table variable with data from PROC1
INSERT INTO #tbl EXECUTE PROC1
-- Do some stuff to the data
-- 'Return' it
SELEC * FROM #tbl
GO

Internal implementation restrictions.
If you need to capture the output of stored procedures, then those procedures should be a table valued function to start with. Ultimately you can work around the restriction by using CLR procedures.

Related

Insert stored procedure results into temp table

I have a stored procedure that returns this result:
The way I call the stored procedure is:
Exec uspGetStandardUsingRoleandPhase '1908003'
I want to store these results into a temp table so I used insert into like this:
IF OBJECT_ID(N'tempdb.dbo.#tmp', N'U') IS NOT NULL
DROP TABLE #tmp
CREATE TABLE #tmp
(
startDate DATE,
endDate DATE,
strPhase NVARCHAR(50),
strBadgeNumber NVARCHAR(30)
)
INSERT INTO #tmp (startDate, endDate, strPhase, strBadgeNumber)
EXEC uspGetStandardUsingRoleandPhase '1908003'
But I get an error like this:
INSERT EXEC failed because the stored procedure altered the schema of the target table.
Hard to say without seeing the code to the stored procedure, but my guess is that the procedure also creates a temp table named #tmp. Try creating a temp table with a different name and running your INSERT EXEC into that, or post the code to the procedure so we can see it.
Worth noting this can also come up in SQL 2016 if you're using Query Store, and it happens to run a clean up during the procedure's execution. They suggest increasing the Query Store size to reduce the likelihood, but other than that, they're not planning to fix it for SQL 2016 (it's fixed in 2017)
https://support.microsoft.com/en-us/help/4465511/error-556-insert-exec-failed-stored-procedure-altered-table-schema

Using results of one stored procedure in another stored procedure - SQL Server

Is there any way to use the results of one stored procedure in another stored procedure without using a table variable or temp table? The logic is as follows:
IF (#example = 1)
BEGIN
DECLARE #temp TABLE (Id INT);
INSERT INTO #temp
EXEC [Procedure1] #ItemId = #StockId
set #Cost = (select top 1 id from #temp)
Ideally i would like to know if there is a way to do this without having to use a temp table. Looked around online but can't find anything that works. Any advice would be great.
In general, if you want to use user-defined code in a SELECT, then it is better to phrase the code as a user-defined function rather than a user-defined procedure.
That is, procedures should be used for their side effects and functions should be used for their return values.
That said, you can use openquery (documented here) to run an exec on a linked server. The linked server can be the server you are running on.

sp_executesql with user defined table type not working with two databases [duplicate]

I'm using SQL Server 2008.
How can I pass Table Valued parameter to a Stored procedure across different Databases, but same server?
Should I create the same table type in both databases?
Please, give an example or a link according to the problem.
Thanks for any kind of help.
In response to this comment (if I'm correct and that using TVPs between databases isn't possible):
What choice do I have in this situation? Using XML type?
The purist approach would be to say that if both databases are working with the same data, they ought to be merged into a single database. The pragmatist realizes that this isn't always possible - but since you can obviously change both the caller and callee, maybe just use a temp table that both stored procs know about.
I don't believe it's possible - you can't reference a table type from another database, and even with identical type definitions in both DBs, a value of one type isn't assignable to the other.
You don't pass the temp table between databases. A temp table is always stored in tempdb, and is accessible to your connection, so long as the connection is open and the temp table isn't dropped.
So, you create the temp table in the caller:
CREATE TABLE #Values (ID int not null,ColA varchar(10) not null)
INSERT INTO #Values (ID,ColA)
/* Whatever you do to populate the table */
EXEC OtherDB..OtherProc
And then in the callee:
CREATE PROCEDURE OtherProc
/* No parameter passed */
AS
SELECT * from #Values
Table UDTs are only valid for stored procs within the same database.
So yes you would have to create the type on each server and reference it in the stored procs - e.g. just run the first part of this example in both DBs http://msdn.microsoft.com/en-us/library/bb510489.aspx.
If you don't need the efficency you can always use other methods - i.e. pass an xml document parameter or have the s.p. expect a temp table with the input data.
Edit: added example
create database Test1
create database Test2
go
use Test1
create type PersonalMessage as TABLE
(Message varchar(50))
go
create proc InsertPersonalMessage #Message PersonalMessage READONLY AS
select * from #Message
go
use Test2
create type PersonalMessage as TABLE
(Message varchar(50))
go
create proc InsertPersonalMessage #Message PersonalMessage READONLY AS
select * from #Message
go
use Test1
declare #mymsg PersonalMessage
insert #mymsg select 'oh noes'
exec InsertPersonalMessage #mymsg
go
use Test2
declare #mymsg2 PersonalMessage
insert #mymsg2 select 'oh noes'
exec InsertPersonalMessage #mymsg2
Disadvantage is that there are two copies of the data.
But you would be able to run the batch against each database simultaneously.
Whether this is any better than using a table table is really down to what processing/data sizes you have - btw to use a temp table from an s.p. you just access it from the s.p. code (and it fails if it doesn't exist).
Another way to solve this (though not necessarily the correct way) is to only utilize the UDT as a part of a dynamic SQL call.
USE [db1]
CREATE PROCEDURE [dbo].[sp_Db2Data_Sync]
AS
BEGIN
/*
*
* Presumably, you have some other logic here that requires this sproc to live in db1.
* Maybe it's how you get your identifier?
*
*/
DECLARE #SQL VARCHAR(MAX) = '
USE [db2]
DECLARE #db2tvp tableType
INSERT INTO #db2tvp
SELECT dataColumn1
FROM db2.dbo.tblData td
WHERE td.Id = ' + CAST(#YourIdentifierHere AS VARCHAR) '
EXEC db2.dbo.sp_BulkData_Sync #db2tvp
'
EXEC(#SQL)
END
It's definitely not a purist approach, and it doesn't work for every use case, but it is technically an option.

Select Values From SP And Temporary Tables

I have a Stored Procedure in MSSQL 2008, inside of this i've created a Temporary Table, and then i executed several inserts into the temporary Table.
How can i select all the columns of the Temporary Table outside the stored procedure? I Mean, i have this:
CREATE PROCEDURE [dbo].[LIST_CLIENTS]
CREATE TABLE #CLIENT(
--Varchar And Numeric Values goes here
)
/*Several Select's and Insert's against the Temporary Table*/
SELECT * FROM #CLIENT
END
In another Query i'm doing this:
sp_configure 'Show Advanced Options', 1
GO
RECONFIGURE
GO
sp_configure 'Ad Hoc Distributed Queries', 1
GO
RECONFIGURE
GO
SELECT *
INTO #CLIENT
FROM OPENROWSET
('SQLOLEDB','Server=(local);Uid=Cnx;pwd=Cnx;database=r8;Trusted_Connection=yes;
Integrated Security=SSPI',
'EXEC dbo.LIST_CLIENTS ''20110602'', NULL, NULL, NULL, NULL, NULL')
But i get this error:
Msg 208, Level 16, State 1, Procedure LIST_CLIENTS, Line 43
Invalid object name '#CLIENT'.
I've tried with Global Temporary Tables and It doesn't work.
I know that is the scope of the temporary table, but, how can i get the table outside the scope of the SP?
Thanks in advance
I think there is something deeper going on here.
One idea is to use a table variable inside the stored procedure instead of a #temp table (I have to assume you're using SQL Server 2005+ but it's always nice to state this up front). And use OPENQUERY instead of OPENROWSET. This works fine for me:
USE tempdb;
GO
CREATE PROCEDURE dbo.proc_x
AS
BEGIN
SET NOCOUNT ON;
DECLARE #x TABLE(id INT);
INSERT #x VALUES(1),(2);
SELECT * FROM #x;
END
GO
SELECT *
INTO #client
FROM OPENQUERY
(
[loopback linked server name],
'EXEC tempdb.dbo.proc_x'
) AS y;
SELECT * FROM #client;
DROP TABLE #client;
DROP PROCEDURE dbo.proc_x;
Another idea is that perhaps the error is occurring even without using SELECT INTO. Does the stored procedure reference the #CLIENT table in any dynamic SQL, for example? Does it work when you call it on its own or when you just say SELECT * FROM OPENROWSET instead of SELECT INTO? Obviously, if you are working with the #temp table in dynamic SQL you're going to have the same kind of scope issue working with a #table variable in dynamic SQL.
At the very least, name your outer #temp table something other than #CLIENT to avoid confusion - then at least nobody has to guess which #temp table is not being referenced correctly.
Since the global temp table failed, use a real table, run this when you start your create script and drop the temp table once you are done to make sure.
IF OBJECT_ID('dbo.temptable', 'U') IS NOT NULL
BEGIN
DROP TABLE dbo.temptable
END
CREATE TABLE dbo.temptable
( ... )
You need to run the two queries within the same connection and use a global temp table.
In SQL Server 2008 you can declare User-Defined Table Types which represent the definition of a table structure. Once created you can create table parameters within your procs and pass them a long and be able to access the table in other procs.
I guess the reason for such behavior is that when you call OPENROWSET from another server it firstly and separately requests the information about procedure output structure (METADATA). And the most interesting thing is that this output structure is taken from the first SELECT statement found in the procedure. Moreover, if the SELECT statement follows the IF-condition the METADATA request ignores this IF-condition, because there is no need to run the whole procedure - the first met SELECT statement is enough. (By the way, to switch off that behavior, you can include SET FMTONLY OFF in the beginning of your procedure, but this might increase the procedure execution time).
The conclusions:
— when the METADATA is being requested from a temp table (created in a procedure) it does not actually exists, because the METADATA request does not actually run the procedure and create the temp table.
— if a temp table can be replaced with a table variable it solves the problem
— if it is vital for the business to use temp table, the METADATA request can be fed with fake first SELECT statement, like:
declare #t table(ID int, Name varchar(15));
if (0 = 1) select ID, Name from #t; -- fake SELECT statement
create table #T (ID int, Name varchar(15));
select ID, Name from #T; -- real SELECT statement
— and one more thing is to use a common trick with FMTONLY (that is not my idea) :
declare #fmtonlyOn bit = 0;
if 1 = 0 set #fmtonlyOn = 1;
set fmtonly off;
create table #T (ID int, Name varchar(15));
if #fmtonlyOn = 1 set fmtonly on;
select ID, Name from #T;
The reason you're getting the error is because the temp table #Client was not declared before you ran the procedure to insert into it. If you declare the table, then execute the list proc and use direct insert -
INSERT INTO #Client
EXEC LIST_CLIENTS

Is it possible to pass a table name into a stored proc and use it without the Exec Function?

I would like to create a SP or UDF where I supply a table and column name as a parameter and it does something to that target. I'm using Sql Server 2005
Trivial Example of what I'm trying to accomplish:
CREATE FUNCTION Example (#TableName AS VARCHAR(100))
RETURNS TABLE
AS
BEGIN
SELECT *
INTO #temp
FROM #TableName
RETURN #temp
END
The example is just something trivial to illustrate what I'm trying to accomplish in terms of passing the Table name as a parameter.
Is this possible to do w/o concatinating strings and calling the EXEC function?
Ultimately, I'm trying to convert the answer from this question into something reusable.
This reeks of SQL injection. You would still need to use EXEC to do this.
No. Can't do it. Sadly, there is no macro pre-complier in T-SQL. The closest you'll get is SQLCMD mode, but that's only for scripts, can't use it in object definitions.
Are you doing the same thing to the table each time?
You could dynamically redefine a synonym, but that still requires an EXEC and you lose concurrency. You could serialize execution with a queue, but at that point you may be better off w/ plain old dynamic SQL.
You might try temporary tables, not passed in as a variable, but created in the parent connection or calling procedure. eg.
create proc #proc as
select * from #table
go
create table #table (col1 int)
insert #table values (1)
insert #table values (2)
insert #table values (3)
go
exec #proc
go
For more ways to share data between stored procedures, see here: http://www.sommarskog.se/share_data.html