Error declarations for error reporting to the Client

Question

Hi,
I am trying to standardize the error reporting from PL/SQL for our project.
I created a package to define these errors and want to declare them as constants.
Unfortunately i'm running into some restrictions.
Option1:
Declare the ErrCd as a constant (-20000 To -20999) and then use an associative array with the ErrCd as index and the text as the value.
Option 2:
Declare a Record type with the ErrCd and ErrText as fields. Associate the errormessage with a position eg errIdx := 1; This will then be the position in the nested table. The procedures will then reference the correct errorRec through the ErrIdx.
The problem is that i want to do all this in the package spec. I don't want to work through a function to first build up the table and then return the correct error record etc.
I cannot build the associative array in the declaration since it doesn't have a constructor.
Nested tables seemed like the one to use since i could build up its content through its constructor. But i cannot construct the errRecord in a similar way.
SUBTYPE ErrIdxType    IS INTEGER;
  SUBTYPE ErrCdType     IS INTEGER;
  SUBTYPE ErrTxtType    IS VARCHAR2(300);
  ERR_CD_BASE           CONSTANT ErrCdType := -19999;
  ERR_CD_MAX            CONSTANT ErrCdType := -20999;
  TYPE ERR_REC IS RECORD
    errCd   ErrCdType,
    errTxt  ErrTxtType
-- Error 1 tester
  ERR_ERR1_IDX        CONSTANT ErrIdxType := 1;
  ERR_ERR1_CD         CONSTANT ErrCdType  := ERR_CD_BASE - ERR_ERR1_IDX;
  ERR_ERR1_TXT        CONSTANT ErrTxtType := 'Error ERR1 occured.';
  -- Error 2 tester
  ERR_ERR2_IDX        CONSTANT ErrIdxType := 2;
  ERR_ERR2_CD         CONSTANT ErrCdType  := ERR_CD_BASE - ERR_ERR2_IDX;
  ERR_ERR2_TXT        CONSTANT ErrTxtType := 'Error ERR2 occured.';
  TYPE ErrTableType IS TABLE OF ERR_REC;
errTable ErrTableType :=
    ErrTableType
      ERR_REC(ERR_ERR1_CD, ERR_ERR1_TXT),
      ERR_REC(ERR_ERR2_CD, ERR_ERR2_TXT)
    );I suppose the java still has a strong grip on me here.
What is the correct way to manage these error definitions?
Since i am trying to establish the error/exception handling strategy for the project i would also greatly appreciate a couple of pointers to examples/packages/docs on the error /exception reporting mechanisms available.
Thanks
Buks

Answer 1

That looks like data to me. Now if only PL/SQL had some kind of a database that came with it so you put that data in a table ;)
Error messages change and so are not good candidates for constants. What you could find useful to declare in a package is some exceptions. You will find more about them in the PL/SQL Guide.
You should also check this series of Oracle Magazine articles written by Steven Feuerstein (Whom God Preserve).
Cheers, APC