ODBC universal way to get deleted rows in trigger - sql

Is there any universal way to get the deleted/inserted/updated rows in trigger? I want to create one trigger (I mean one pice of code in my application), which should work on Oracle, Sql Server and Postgres. Is it possible? I'm using odbc drivers to connect to different dbs.
It's working in SQL Server, but not in Oracle.
CREATE TRIGGER schema.trg_nameON schema.table_name
FOR DELETE
AS
BEGIN
DECLARE #id BIGINT;
SELECT #id = d.ID
FROM deleted d
DELETE
FROM schema.table_name
WHERE TOP_ID = #id;
END

no, each RDMS will have its own syntax. The syntax you used is a sql server syntax.
what do you mean by create trigger on the application? Please provide us with more info

Related

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"

creating a trigger that updates row in a linked mysql server

i created a linked Mysql server on SQL server 2008 r2. i'm trying to create a trigger on sql table that automatically updates a field in the linked server table, i have a table called "QFORCHOICE" in sql that has fields "Prodcode,prodname and avqty" and a table "que_for_choie" in mysql that has fields "procode,proname and avqty"
i want the trigger to update the value of "procode" in the linked server if the value of "prodcode" in sql server changes. this is what i have so far but it has errors,
create trigger [QFORCHOICE]
ON dbo.QFORCHOICE
FOR INSERT
AS
DECLARE #prodcode numeric(18,0)
DECLARE #prodname varchar(50)
DECLARE #avqty numeric(18,0)
BEGIN
SELECT
#procode = procode,
#proname = proname,
#avqty = avqty
FROM inserted
update [LINKED_MYSQL].[que_for_choice]
SET prodname=#prodname,avqty=#avqty
WHERE prodcode = #prodcode
end
can anybody please help.
thanks in advance
1- From within a trigger, you shouldn't attempt to access anything external to the current database. It will severely slow down any insert activity, and if there are any networking issues or the remote server is down for any reason, you'll then cause the original transaction to roll back. This is rarely the right thing to do
2- you're making the reliability of your system dependent on the reliability of two servers rather than one (say they both have 99% reliability - your system that ties them together with a trigger now has 98% overall reliability).

Insert value to another sqlserver db

I have 2 SQL Servers:
temp1 XX.13.23.2
temp2 XX.23.45.6
The temp1 server has a database called db1 and contains a procedure called p1.
I want that procedure to insert the value on Temp2 server Database name db2 on table T1.
Is it possible to use procedure to insert value on another server's database?
If this is this possible then can someone provide me with an idea or some examples on how to achieve this?
Yes, please look into linked servers:
http://msdn.microsoft.com/en-us/library/ms188279%28SQL.90%29.aspx
You can call a remote stored procedure from the instance you want to insert to:
exec [RemoteServer].DatabaseName.DatabaseOwner.StoredProcedureName
You need to have the RemoteServer set up as a linked server.
Another option, especially if you're going to have a development version of the procedure where you're going to want to do tests and you don't want touching a production environment, would be to use SQL Server synonyms: http://technet.microsoft.com/en-us/library/ms177544.aspx.
I personally like using them because once the proc is initially setup to use them, you won't have to change the SQL in the procedure.

Link Server Optimization Help

I have this code in a trigger.
if isnull(#d_email,'') <> isnull(#i_email,'')
begin
update server2.database2.dbo.Table2
set
email = #i_email,
where user_id = (select user_id from server2.database2.dbo.Table1 where login = #login)
end
I would like to update a table on another db server, both are MSSQL. the query above works for me but it is taking over 10 seconds to complete. table2 has over 200k records. When I run the execution plan it says that the remote scan has a 99% cost.
Any help would be appreciated.
First, the obvious. Check the indexes on the linked server. If I saw this problem without the linked server issue, that would be the first thing I would check.
Suggestion:
Instead of embedding the UPDATE in the server 1 trigger, create a stored procedure on the linked server and update the records by calling the stored procedure.
Try to remove the sub-query from the UPDATE:
if isnull(#d_email,'') <> isnull(#i_email,'')
begin
update server2.database2.dbo.Table2
set email = #i_email
from server2.database2.dbo.Table2 t2
inner join
server2.database2.dbo.Table1 t1
on (t1.user_id = t2.user_id)
where t1.login = #login
end
Whoa, bad trigger! Never and I mean never, never write a trigger assuming only one record will be inserted/updated or deleted. You SHOULD NOT use variables this way in a trigger. Triggers operate on batches of data, if you assume one record, you will create integrity problems with your database.
What you need to do is join to the inserted table rather than using a varaible for the value.
Also really updating to a remote server may not be such a dandy idea in a trigger. If the remote server goes down then you can't insert anything to the orginal table. If the data can be somewaht less than real time, the normal technique is to have the trigger go to a table on the same server and then a job pick up the new info every 5-10 minutes. That way if the remote server is down, the records can still be inserted and they are stored until the job can pick them up and send them to the remote server.

Trigger to capture schema changes in the Server

Is it possible to implement something like the following trigger
CREATE TRIGGER [tr_AU_ddl_All_Server] ON DATABASE
WITH EXECUTE AS self
FOR DDL_DATABASE_LEVEL_EVENTS
AS
DECLARE
#data XML
, #rc INT
SET #data = EVENTDATA()
EXEC #rc = __AU.dbo.AU_DDLLog #data
GO
BUT on the whole server. My idea is to capture all schema changes across all the databases in the server.
As far as im concerned this is not possible in SQL Server 2005, but I'd like to know if anyone got something like this to work. I'd like to avoid having to implement a trigger in every single database.
Yes, SQL Server 2005 introducted the "DDL Triggers" - read an excellent article on it here at SQL Team.
This article shows nicely that they are two scopes for DDL triggers - server-wide, or database-wide. Those that are database-wide cannot be applied to the whole server - you'd have to set them up in each database.
Marc