Multiple Go in stored procedure - sql-server

I'd like to write a stored procedure and store it in a SQL Server database. The procedure is supposed to remove all tables regardless of dependency constraints.
CREATE PROCEDURE sp_clear_db AS
BEGIN
EXEC sp_MSForEachTable 'ALTER TABLE ? NOCHECK CONSTRAINT ALL';
EXEC sp_MSForEachTable 'DROP TABLE ?';
END
However, when I call sp_helptext #objname = 'dbo.sp_clear_db', only the first exec statement is shown. I assume in order to execute the first function, a GO has to be called. But a GO as part of the stored procedure definition won't work either. Does anyone know a way to fix this? Maybe there is another better option to achieve the same...
Cheers,
Max

You can't have "GO" in a stored procedure. (http://msdn.microsoft.com/en-us/library/ms188037.aspx) GO is used by SQL Query analyser to separate statements into "Batches" which are then sent to SQL server. So you'd need to make two separate calls, one for the ALTER calls and one for the DROP.
Ideally you would just call "DROP DATABASE" unless you were trying to keep your stored procs and then re-create the tables.
Another solution would be to use a cursor to loop through each row in sys.tables where type='U' and generate some dynamic sql to remove the contraints and drop the table.

Don't use sp_helptext. Use OBJECT_DEFINITION or sys.sql_modules

Related

Sharing stored procedure across database using synonyms

I have two different SQL Server databases (on the same server - if it helps) that need to share the same stored procedure logic. The solution I'm trying to achieve looks like this:
Database1
Table: TestTable
Synonym: sp_MyProc pointing at SharedDatabase.dbo.sp_MyProc
Database2
Table: TestTable
Synonym: sp_MyProc pointing at SharedDatabase.dbo.sp_MyProc
SharedDatabase
Proc: sp_MyProc which runs queries against TestTable
My hope was to use the synonyms so that if I execute sp_MyProc while in the context of Database1, it would use Database2.TestTable. And if I execute sp_MyProc while in the context of Database2, it would go against Database2.TestTable. However, when I execute sp_MyProc through either of the synonyms, it ignores the context of the synonym and executes looking for a local copy of TestTable, which is not found.
Is there a way to implement a shared stored procedure that executes against different copies of tables in different databases, either through synonyms or some other mechanism?
Edit
I should mention that in my case I am looking to do this with a large set of existing tables and procs, so any solution that requires modifying the procs or tables themselves are not ideal.
Something like this would work for the definition of the procedure. Be sure to guard against SQL injection since this is built dynamically.
CREATE PROCEDURE [dbo].dosomething
#databaseName sysname,
#schema sysname,
#tableName sysname
as
declare #cmd as nvarchar(max)
set #cmd = N'select * from ' + quotename(#schema) + N'.' + quotename(#tableName)
exec sp_executesql #cmd
Then use it like this:
dosomething 'SampleDb', 'dbo', 'sampleTable'
If the stored proc is in the SharedDatabase, then it will always run in context of SharedDatabase. To accomplish what you are trying to do to centralize code, I would maybe pass in a parameter to designate which server it is coming from, so then you can execute the query against that specific TestTable. Basically, you will need to refer to each table using their fully qualified name - i.e. Database1.dbo.TestTable
USE SharedDatabase
CREATE PROCEDURE [dbo].sp_MyProc
#dbsource varchar(50)
as
if(#dbsource == 'DB1')
begin
select * from Database1.dbo.TestTable
end
else
begin
select * from Database2.dbo.TestTable
end
GO
The other alternative is to make a view in SharedDatabase, which will be called TestTableComposite, with an extra column to identify where the source data is. And then pass that in as the parameter, and your SP on SharedDatabase will always be in context of that DB.

How can I create a new database with schema within a stored procedure?

I want to write a TSQL stored procedure that creates a database with a specified name, and pre-populates it with some schema.
So I use lots of EXEC statements:
EXEC('CREATE TABLE ' + #dbName + '.dbo.MyTable (...)');
etc, along with some CREATE PROCEDURE, CREATE FUNCTION etc. However, the problem comes from when I want to create a type, as CREATE TYPE statements can't have the database specified, and you can't have USE #dbName within the stored procedure.
How can I create a type in another database in a stored procedure?
There are certain commands that can't use used as ssarabando suggests, among them is CREATE SCHEMA, which throws Msg 111 when used in with that technique.
The work around is to nest dynamic SQL blocks as follows:
exec('use tempdb; exec sp_executesql N''create schema test'' ')
The outer block does nothing except change the database, so that the inner block has the correct context when it is executed.
Notice that the inner parameter to sp_executesql needs two single quotes.
You may want to take a look at sp_addtype instead. You can execute this in the database you want.
You could also use this, for example:
EXEC('use ' + #dbName + ';create type somename from int not null;')
That'll select the correct database before creating the type.

SQL Server Dynamic Stored Procedure

I am having the stored procedure. For that i need to pass the Database name as the paramters from another application or another SP. I know the approach of dynamic SQL, something like,
Create procedure mysp(#dbname varchar(20))
as
begin
declare #sql varchar(max)
set #sql='select * from '+#dbname+'.dbo.table'
end
exec mysp 'mydb'
But i dont want the SQL statements as a string. Because in my SP, i have many Sql statements are coming (Not like this only SELECT statement). so can i use,
USE DatabaseName
inside the stored procedure, so that i can use the db name in the sql statements directly without making it as string. Or any other approach is there.
My requirements, only for db name, i dont want the entire the sql statement to be dynamic...
please help me out.
Thanks in advance.
You can add the USE instruction to the dynamic query you are creating. Then you can work with that database's tables and other objects without the qualifier (within the dynamic query):
Create procedure mysp(#dbname varchar(20))
as
begin
declare #sql varchar(max)
set #sql='use '+#dbname;
set #sql=#sql + ';select ... from dbo.table1';
set #sql=#sql + ';update dbo.table2...';
set #sql=#sql + ';insert into dbo.table3...';
...
exec(#sql);
end
exec mysp 'mydb'
However, while you can do that, it's not something that you should do, unless you really have to. You are probably trying to avoid creating the same procedure in different DBs, but you may be getting you other problems with this approach, or robbing yourself of some advantages you might otherwise have without resorting to dynamic queries in SPs.
No, USE isn't allowed in stored procedures, functions and triggers.
A stored procedure is supposed to be local to the database. To access another database, there is one way (as far as I know), and it's the one you used.

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"

how to create utility stored procedure and run it like other sp_... utilities

I need to create a stored procedure one time and in one place only on my database server, but be able to run it from any database. However, I don't want to have to type database.schema.procedure_name every time I run it. I'd like to be able to use it like the built in procedures: sp_... is there any way to do this?
here is the procedure that I'm trying to create:
--actual procedure is more complex
CREATE PROCEDURE TestProcedure
AS
select * from sys.dm_exec_requests
go
here is how I'd like to run it from SQL Server Management Studio:
EXEC TestProcedure
--or
TestProcedure
however, you you get this error:
Msg 2812, Level 16, State 62, Line 1
Could not find stored procedure 'TestProcedure'.
everything runs fine if I run it with:
EXEC master.dbo.TestProcedure
--or
master.dbo.TestProcedure
you can run system procedures like this without any errors:
EXEC sp_help
--or
sp_help
Just create it in the master database and give it the sp_ prefix and it will work. SQL Server always checks the master database first for stored procedures (and other types of objects as well) with this prefix.
It will handle the datbase context for you as well as below.
USE master
create proc [dbo].[sp_test] as
select db_name()
GO
USE YourDB
EXEC master..sp_test /*Returns "master"*/
EXEC sp_test /*Returns "YourDB"*/
Edit:
Just following up Cade's comment to mark it as a system procedure. This seems like it might well be required in some circumstances. In SQL 2005+ you would use
EXEC sys.sp_MS_marksystemobject 'dbo.sp_test'

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