MyBatis and DBMS_OUTPUT

Question

I am using Oracle/MyBatis and trying to debug a stored procedure with an enormous amount of parameters. Inside the stored procedure I get a ORA-01438: value larger than specified precision allowed for this column

So my initial approach would be to do like dbms_output.put_line in the stored procedure to try to see what the values are right before the offending statement. Without MyBatis, I would ordinarily open up a sqlplus script and type set serveroutput on and then run my stored procedure at some later point to see all the debug messages come out. With MyBatis, I cannot figure out how (if possible) to get these debug statements.

I have the ibatis and sql debuggers set for DEBUG and I use log4j to log everything for my Tomcat 6 application.

Answer 1

The DBMS_OUTPUT package has a few other procedures that you could use. DBMS_OUTPUT.ENABLE functions much like the SQL*Plus command set serveroutput on in that it allocates a buffer for DBMS_OUTPUT.PUT_LINE to write to. DBMS_OUTPUT.GET_LINE can be used to fetch the data written to that buffer by previous calls to DBMS_OUTPUT.PUT_LINE. So it should be possible to call the ENABLE function, call the procedure which writes a number of lines to the buffer, and then call GET_LINE (or GET_LINES) to fetch the data that was written to the DBMS_OUTPUT buffer and write that data to your logs.

It may be simpler, however, to redirect the logging to an Oracle database table rather than trying to use DBMS_OUTPUT. One common approach is to create your own package that has a switch to determine whether to write to DBMS_OUTPUT or whether to write to a table. Something like

CREATE OR REPLACE PACKAGE p
AS
  procedure l( p_str IN VARCHAR2 );
END;

CREATE OR REPLACE PACKAGE BODY p
AS
  g_destination INTEGER;
  g_destination_table    CONSTANT INTEGER := 1;
  g_destination_dbms_out CONSTANT INTEGER := 2;  

  PROCEDURE l( p_str IN VARCHAR2 )
  AS 
  BEGIN
    IF( g_destination = g_destination_dbms_out )
    THEN
      dbms_output.put_line( p_str );
    ELSE
      INSERT INTO log_table ...
    END IF;
  END;

  BEGIN
    g_destination := <<determine which constant to set it to.  This
                       may involve querying a `SETTINGS` table, looking
                       at the environment, or something else>>
  END;
END;