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Translate Pseudocode
into Code
Oracle Tips by
Burleson
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Code
Translating the pseudocode for the package into code is fairly
straightforward. Listing 6.14 contains the package spec and the
package body for the System_Errors package.
Listing 6.14 The package spec for the System_Errors
package.
PACKAGE System_Errors
IS
DELIMITER CONSTANT char (1) := '^';
PROCEDURE Build_Error (vModule IN varchar2,
vProcName IN varchar2,
iErrorNum IN integer,
vDataString IN varchar2,
vDisplayFlag IN varchar2);
PROCEDURE Next_Word (vDataString IN OUT varchar2,
vWord OUT varchar2);
END System_Errors;
PACKAGE BODY System_Errors
-- ******************************************************************
iNextPart integer := 1;
-- ******************************************************************
FUNCTION Next_String (vModule IN varchar2,
iErrorNum IN integer)
RETURN varchar2
IS
vNextStringPart ERROR_MESSAGES.error_text%TYPE;
BEGIN
SELECT error_text
INTO vNextStringPart
FROM ERROR_MESSAGES
WHERE module_name = vModule
AND error_number = iErrorNum
AND error_part = iNextPart;
iNextPart := iNextPart + 1;
RETURN vNextStringPart;
END Next_String;
-- ******************************************************************
PROCEDCURE Build_Error (vModule IN varchar2,
vProcName IN varchar2,
iErrorNum IN integer,
vDataString IN varchar2,
vDisplayFlag IN varchar2)
IS
MODULE CONSTANT varchar2 (6) := 'ERRORS';
PROCEDURE CONSTANT varchar2 (30) := 'Build_Error';
UNKNOWN_ERROR CONSTANT integer := 1;
bRecursion boolean := FALSE;
iSeverity integer;
vDataString varchar2 (200);
vNewMessage varchar2 (200);
vNextPart ERROR_MESSAGES.error_text%TYPE;
vNextWord varchar2 (30);
xRECURSION_ERROR EXCEPTION;
BEGIN
IF NOT bRecursion THEN
bRecursion := FALSE;
END IF;
vDataWords := vDataString;
vNewMessage := NULL;
iNextPart := 1;
--
-- If the module that was specified doesn't exist or the error for
-- the module can't be found, write an "UNKNOWN ERROR" message
-- here. This is combined with the retrieval of the severity_level
-- for the message.
--
BEGIN
SELECT severity_level
INTO iSeverity
FROM ERROR_SEVERITIES
WHERE module_name = vModule
AND error_number = iErrorNum;
EXCEPTION
WHEN NO_DATA_FOUND THEN
IF NOT bRecursion THEN
bRecursion := TRUE;
Build_Error (vModule => MODULE,
vProcName => PROCEDURE,
iErrorNum => UNKNOWN_ERROR,
vDataString => vModule || DELIMITER ||
iErrorNum || DELIMITER ||
vProcName || DELIMITER,
vDisplayFlag => 'Y');
ELSE
RAISE xRECURSION_ERROR;
END IF;
END;
--
-- Get the first part of the error message from the ERROR_MESSAGES
-- table.
--
vNextPart := Next_String (vModule => vModule,
iErrorNum => iErrorNum);
vNewMessage := vNewMessage || vNextPart;
WHILE (instr (vDataString, DELIMITER) > 0) LOOP
--
-- Get the next piece of data from the string.
--
Next_Word (vDataString => vDataWords,
vWord => vNextWord);
--
-- Put the next piece of the error message onto the
-- new message.
--
vNextPart := Next_String (vModule => vModule,
iErrorNum => iErrorNum);
vNewMessage := vNewMessage || vNextWord || vNextPart;
END LOOP;
INSERT
INTO SYSTEM_ERRORS
(error_number,
error_time,
error_text,
displayed)
VALUES (ERROR_SEQ.nextval,
SYSDATE,
vNewMessage,
vDisplayFlag);
END Build_Error;
-- ******************************************************************
PROCEDURE Next_Word (vDataString IN OUT varchar2,
vWord OUT varchar2)
IS
BEGIN
iDelimiterPos := instr (vDataString, DELIMITER);
vWord := substr (vDataString, 1, iDelimiterPos);
vDataString := substr (vDataString, (iDelimiterPos + 1));
END Next_Word;
END System_Errors;
Testing
In reality, packages are not tested; procedures and functions
within the package are tested individually from the lowest point on
the food chain to the highest. Testing a package requires every
subroutine inside the package to be tested thoroughly. References to
global variables, constants, and other constructs should be closely
examined during the test.
Testing private procedures and functions is somewhat difficult.
It’s often easier to test procedures and functions by making them
public for testing purposes, then removing the public definition of
the object from the package spec and then testing the security of the
private object.
Summary
Chapter 6 has discussed the fundamentals of grouping procedures and
functions using packages. At this point, you should be familiar with
the creation of packages and have some insights into designing your
own packages and testing the routines inside a package.
This is an excerpt from the book "High Performance Oracle
Database Automation" by Jonathan Ingram and Donald K.
Burleson, Series Editor. |
