Need help - MS SQL Trigger for Oracle insert

  • Hi,

    is it possible to use a ms sql trigger to insert a row in Oracle Table ? I use this way an get error Error 7391: The operation could not be performed because the OLE DB provider 'SQLOLEDB' was unable to begin a distributed transaction. I reconfig the MSDTS on the Server and allow all connection in and out but still get the error !?

    Is there other way to do this ?? I want to write the triggered Data in to a Oracle Table.

    THX

    MS SQL Trigger !

    CREATE TRIGGER [dbo].[trg_log_changes_table]

    ON [dbo].[TEST]

    FOR INSERT, DELETE, Update

    AS

    Begin Tran

    BEGIN

    IF EXISTS(SELECT * FROM Inserted)

    BEGIN

    INSERT INTO OPENQUERY (

    [xxx],

    'select dt_status,prs_dt_birth, DS_TYPE,DW_DOC_ID,DW_ARCHIVE, DW_MOD_DATE from owner.T_SI_CHANGED')

    SELECT

    GETDATE () AS DT_Status,

    GETDATE () AS prs_dt_birth,

    'I' AS DS_TYPE,

    DWDOCID AS DW_DOC_ID,

    PRODUNIT AS DW_ARCHIVE,

    DWMODDATETIME AS DW_MOD_DATE

    FROM Inserted

    END

  • Triggers are hard to test and debug, have you tested the insert string outside of the trigger (obviously needs a bit of rewriting) ?

    Your problem sounds like less to do with the fact that it is in a trigger and more to do with the actual insert.

    I had a similar hiccup when trying to write to MySQL, turned out to be different data types related.

  • Hi,

    the Insert Statment works alone fine i have test it. I get the error with the Trigger !!

  • I think so in this style it would work but I have no idea with dynamic SQL can anyone help me here?

    What is missing in the trigger?

    CREATE TRIGGER [dbo].[trg_log_changes_france4]

    ON [dbo].[TEST]

    FOR INSERT, DELETE, Update

    AS

    declare @DWDOCID int

    declare @DWMODDATE DATETIME

    declare @DWPRODUNIT INT

    declare @TYPE CHAR(1)

    declare @DT_STATUS datetime

    declare @PRS_DT_BIRTH

    set @DWDOCID = (SELECT DWDOCID FROM inserted)

    set @DWMODDATE = (SELECT DWMODDATETIME FROM inserted)

    set @DWPRODUNIT = (SELECT PRODUNIT FROM inserted)

    IF EXISTS(SELECT * FROM Inserted)

    BEGIN

    declare @query NVARCHAR(500);

    set @query ='INSERT INTO OPENQUERY([VPHIN], 'select dt_status,prs_dt_birth, DS_TYPE,DW_DOC_ID,DW_ARCHIVE, DW_MOD_DATE from owner.T_SI_CHANGED'';

    SELECT @DT_STATUS=Getdata(), @PRD_DT_BIRTH=Getdata(), @DS_TYPE='I', @DWDOCID, @DWPRODUNIT, @DWMODDATE FROM Inserted

    execute sp_executesql @query

    End

  • This is not going to scale.

    This statement:

    'select dt_status,prs_dt_birth, DS_TYPE,DW_DOC_ID,DW_ARCHIVE, DW_MOD_DATE from owner.T_SI_CHANGED

    Is selecting ALL of the rows from T-SI_CHANGED.... before you even insert anything.

    So what happens after a month when T_SI_CHANGED has a zillion records and your trigger is run a dozen times to insert some records? It selects the entire T_SI_CHANGED table a dozen times on the Oracle side.

    Possible solutions to this:

    1. Change it to this, so that no rows need to be selected on the Oracle side

    'select dt_status,prs_dt_birth, DS_TYPE,DW_DOC_ID,DW_ARCHIVE, DW_MOD_DATE from owner.T_SI_CHANGED WHERE 1=0

    2. Use this instead (which does not even require a select on the Oracle side:

    INSERT INTO [VPHIN].owner.T_SI_CHANGED (col1,col2) SELECT COl1, Col2 from INSERTED

    However linked servers in general can unreliable, especially to Oracle are unreliable. So if this Oracle insert fails, your trigger fails, and then the change on the SQL Server side failes.

    I suggest that you instead write the changes to a log table on the SQL Server side, then use a scheduled job to send over the logged records to the Oracle table in a batch (via SSIS or linked servers). This disconnects the 'data transfer' part from the 'trigger' part, and will stop errors occuring when you insert on the SQL side (due to your trigger failing)

  • I'm pretty sure SQL Server 2005 onwards supports replication to Oracle, which is what you're trying to do.

    It looks complicated but it's the 'out of the box' way to do it.

    http://msdn.microsoft.com/en-us/library/ms151738(v=sql.90).aspx

  • Hi,

    you mean I should create a trigger with (Del, ins and the upd Option) on ms sql table and then write the data to the Oracle table.

    Just how can i do it, to write the data generated by the trigger to Oracle table over (SSIS-Package) ?

    Can you tell me how can I do that?

    THX

  • I suggest one of two options:

    A. Use out of the box SQL to Oracle replication

    OR

    B. Log the changes locally and send them over in batch:

    1. Create a log table on the SQL Server

    2. Your trigger should write to this log table (not to Oracle). This means you won't run the risk of an DML failing in your SQL Server database due to an unreliable trigger failure

    3. Create a job which periodically identifies the changed records in the log in the SQL Server and writes them accross to Oracle.

    This job might call a SSIS package, or it might call a stored procedure that inserts into an Oracle linked server.

    Niether of these are simple, but they will be more reliable than useing a trigger to write directly Oracle over a linked server.

    The problem is that if your insert over a linked server on Oracle fails (which it might for many reasons), then the INSERT on the SQL Server will also fail.

  • o.k thx i have create the trigger and stored procedure on ms sql side and run in period. the sp and it

    works fine thx 🙂

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