Creating Procedures with Transactions using PGAdmin 4 - pgadmin-4

I'm coming from a long history with SQL Server and trying to learn PL/PGSQL. I've recently discovered the PG11 feature CREATE PROCEDURE which allows for internal transactions inside their body.
As a learning exercise, I've created this:
DROP PROCEDURE IF EXISTS test_proc();
CREATE PROCEDURE test_proc()
LANGUAGE plpgsql
AS $$
BEGIN
DROP TABLE IF EXISTS a;
CREATE TABLE a (aid int);
COMMIT;
END;
$$;
call test_proc();
It works fine in PSQL, however when I execute it in PGAdmin 4's Query Tool, it errors with
ERROR: invalid transaction termination
CONTEXT: PL/pgSQL function test_proc() line 5 at COMMIT
SQL state: 2D000
Can someone please explain what's going on? I'm guessing that the PROCEDURE is in fact valid and the issue might be in the query tool might be incorrectly processing the contained COMMIT.
Are there any suggestions for working around this?
Thanks!

In Pgadmin CREATE PROCEDURE as FUNCTION
please try this by Replace PROCEDURE with Function and add Return type also and it will work
DROP FUNCTION IF EXISTS test_proc();
CREATE FUNCTION test_proc()
RETURNS VOID
LANGUAGE plpgsql
AS $$
BEGIN
DROP TABLE IF EXISTS a;
CREATE TABLE a (aid int);
COMMIT;
END;
$$;

Can you please try unchecking auto commit & auto rollback options in pgAdmin4?
You can find drop down near Execute button in the query tool.

Related

Oracle Stored Procedure not working, likely because of syntax

I know I am an idiot.. But I have been trying to create this simple stored procedure in my Oracle database for some time now and I keep getting the error "procedure created with compilation errors". I can't seem to find anything wrong with it and I am following the syntax I have found online. I am using an Oracle xe 11g server with pl/sql 11. Please help!
CREATE OR REPLACE PROCEDURE hr.countEmployee(passin IN NUMBER)
IS
BEGIN
SELECT COUNT(*) FROM hr.mitch_employee_motors WHERE hr.mitch_employee_motors.deptno = hr.countemployee.passin;
END;
Aleksej hit the nail on the head and I follow up with the code that reflects his comment.
CREATE OR REPLACE PROCEDURE hr.countemployee (passin IN NUMBER)
IS
l_count INTEGER;
BEGIN
SELECT COUNT (*) INTO l_count
FROM hr.mitch_employee_motors
WHERE hr.mitch_employee_motors.deptno = hr.countemployee.passin;
DBMS_OUTPUT.PUT_LINE (l_count);
END;
What are you using the write and execute your SQL and PL/SQL? I encourage you to try out SQL Developer. It would have helped you a whole lot in diagnosing the issue.
You can try:
CREATE OR REPLACE PROCEDURE hr.countEmployee(passin IN NUMBER,OUT_CURSOR OUT sys_refcursor)
IS
BEGIN
OPEN OUT_CURSOR FOR
SELECT COUNT(*) FROM hr.mitch_employee_motors WHERE hr.mitch_employee_motors.deptno = hr.countemployee.passin;
END;

How to change schema of tables used in stored procedure

I have procedure dbo.GetData:
Create procedure dbo.GetData
As
Begin
Select * from dbo.tblName
End
And I also created a schema [ABC], table ABC.tblName
So, I would like to change schema [dbo] of table in procedure dbo.GetData into [ABC] by using another stored procedure.
And, the result is:
Create procedure dbo.GetData
As
Begin
Select * from [ABC].tblName
End
How can I do it?
Thank you everyone.
I'm not sure I understand what you're asking, but I think you simply want to change the code being executed in the stored procedure. If so, a simple ALTER PROCEDURE would do the trick to change the code, but not the name:
ALTER PROCEDURE dbo.GetData
AS
BEGIN
SELECT * FROM [ABC].tblName
END
Full syntax of [ALTER PROCEDURE] 1 (for SQL Server)
If this is not what you're after, please clarify the question.
Update:
The only real solution I see is that you script out your procs, and then use a text-editor to replace the dbo. values with [ABC]. values.
I just attempted to try and do this through updating the system tables, but in SQL Server 2012 (which I use), it simply gets far too complex for that.
Try this hope this may help you!
ALTER SCHEMA NewSchemaName TRANSFER OldSchemaName.ObjectName

Create database using a stored function

I am new to PostgreSQL and want to create a database using a stored function.
For ex:
CREATE OR REPLACE FUNCTION mt_test(dbname character varying)
RETURNS integer AS
$BODY$
Create Database $1;
Select 1;
$BODY$
LANGUAGE sql;
When I am trying to execute this function I get a syntax error.
Does Postgres support the CREATE DATABASE statement in stored functions?
This question is old, but for the sake of completeness ...
As has been pointed out in other answers, that's not simply possible because (per documentation):
CREATE DATABASE cannot be executed inside a transaction block.
It has also been reported that the restriction can be bypassed with dblink.
How to use (install) dblink in PostgreSQL?
What was missing so far is a proper function actually doing it:
CREATE OR REPLACE FUNCTION f_create_db(dbname text)
RETURNS integer AS
$func$
BEGIN
IF EXISTS (SELECT 1 FROM pg_database WHERE datname = dbname) THEN
RAISE NOTICE 'Database already exists';
ELSE
PERFORM dblink_exec('dbname=' || current_database() -- current db
, 'CREATE DATABASE ' || quote_ident(dbname));
END IF;
END
$func$ LANGUAGE plpgsql;
Checks if the db already exists in the local cluster. If not, proceed to create it - with a sanitized identifier. We would not want to invite SQL injection.
You can't create a database inside of a function because it's not possible to create a database inside a transaction.
But most probably you don't mean to create databases but schemas, which more closely resemble the MySQL's databases.
I found a tricky solution to this problem, but possible. After looking and reading almost in everywhere I tried something and it worked.
if the error is "CREATE DATABASE cannot be executed from a function or multi-command string" we can force a single command string using dblink. And make it to connect to itself.
Check for dblink installation instructions at dblink
PERFORM replication.dblink_connect('myconn','host=127.0.0.1 port=5432 dbname=mydb user=username password=secret');
PERFORM replication.dblink_exec('myconn', 'CREATE DATABASE "DBFROMUSER'||id||'" TEMPLATE "TEMPL'||type||'";',false);
PERFORM replication.dblink_disconnect('myconn');
In my case using different kinds of template.
Greetings
postgres=> create or replace function mt_test(dbname text)
returns void language plpgsql as $$
postgres$> begin
postgres$> execute 'create database '||$1;
postgres$> end;$$;
CREATE FUNCTION
postgres=> select work.mt_test('dummy_db');
ERROR: CREATE DATABASE cannot be executed from a function or multi-command string
CONTEXT: SQL statement "create database dummy_db"
PL/pgSQL function "mt_test" line 2 at EXECUTE statement
postgres=>
note the error message: CREATE DATABASE cannot be executed from a function or multi-command string
so the answer to the question:
Does postgresql support creating statement in stored function
is "no" (at least on 8.4 - you don't specify your version)

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 do I conditionally create a stored procedure in SQL Server?

As part of my integration strategy, I have a few SQL scripts that run in order to update the database. The first thing all of these scripts do is check to see if they need to run, e.g.:
if #version <> #expects
begin
declare #error varchar(100);
set #error = 'Invalid version. Your version is ' + convert(varchar, #version) + '. This script expects version ' + convert(varchar, #expects) + '.';
raiserror(#error, 10, 1);
end
else
begin
...sql statements here...
end
Works great! Except if I need to add a stored procedure. The "create proc" command must be the only command in a batch of sql commands. Putting a "create proc" in my IF statement causes this error:
'CREATE/ALTER PROCEDURE' must be the first statement in a query batch.
Ouch! How do I put the CREATE PROC command in my script, and have it only execute if it needs to?
Here's what I came up with:
Wrap it in an EXEC(), like so:
if #version <> #expects
begin
...snip...
end
else
begin
exec('CREATE PROC MyProc AS SELECT ''Victory!''');
end
Works like a charm!
SET NOEXEC ON is good way to switch off some part of code
IF NOT EXISTS (SELECT * FROM sys.assemblies WHERE name = 'SQL_CLR_Functions')
SET NOEXEC ON
GO
CREATE FUNCTION dbo.CLR_CharList_Split(#list nvarchar(MAX), #delim nchar(1) = N',')
RETURNS TABLE (str nvarchar(4000)) AS EXTERNAL NAME SQL_CLR_Functions.[Granite.SQL.CLR.Functions].CLR_CharList_Split
GO
SET NOEXEC OFF
Found here:
https://codereview.stackexchange.com/questions/10490/conditional-create-must-be-the-only-statement-in-the-batch
P.S. Another way is SET PARSEONLY { ON | OFF }.
But watch out for single quotes within your Stored Procedure - they need to be "escaped" by adding a second one. The first answer has done this, but just in case you missed it. A trap for young players.
Versioning your database is the way to go, but... Why conditionally create stored procedures. For Views, stored procedures, functions, just conditionally drop them and re-create them every time. If you conditionally create, then you will not clean-up databases that have a problem or a hack that got put in 2 years ago by another developer (you or I would never do this) who was sure he would remember to remove the one time emergency update.
Problem with dropping and creating is you lose any security grants that had previously been applied to the object being dropped.
This is an old thread, but Jobo is incorrect: Create Procedure must be the first statement in a batch. Therefore, you can't use Exists to test for existence and then use either Create or Alter. Pity.
It is much better to alter an existing stored proc because of the potential for properties and permissions that have been added AND which will be lost if the stored proc is dropped.
So, test to see if it NOT EXISTS, if it does not then create a dummy proc. Then after that use an alter statement.
IF NOT EXISTS(SELECT * FROM sysobjects WHERE Name = 'YOUR_STORED_PROC_NAME' AND xtype='P')
EXECUTE('CREATE PROC [dbo].[YOUR_STORED_PROC_NAME] as BEGIN select 0 END')
GO
ALTER PROC [dbo].[YOUR_STORED_PROC_NAME]
....
I must admit, I would normally agree with #Peter - I conditionally drop and then unconditionally recreate every time. I've been caught out too many times in the past when trying to second-guess the schema differences between databases, with or without any form of version control.
Having said that, your own suggestion #Josh is pretty cool. Certainly interesting. :-)
My solution is to check if the proc exists, if so then drop it, and then create the proc (same answer as #robsoft but with an example...)
IF EXISTS(SELECT * FROM sysobjects WHERE Name = 'PROC_NAME' AND xtype='P')
BEGIN
DROP PROCEDURE PROC_NAME
END
GO
CREATE PROCEDURE PROC_NAME
#value int
AS
BEGIN
UPDATE SomeTable
SET SomeColumn = 1
WHERE Value = #value
END
GO
use the 'Exists' command in T-SQL to see if the stored proc exists. If it does, use 'Alter', else use 'Create'
IF NOT EXISTS(SELECT * FROM sys.procedures WHERE name = 'pr_MyStoredProc')
BEGIN
CREATE PROCEDURE pr_MyStoredProc AS .....
SET NOCOUNT ON
END
ALTER PROC pr_MyStoredProc
AS
SELECT * FROM tb_MyTable

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