Directory File List in PL/SQL (Oracle 10g)

UTL_FILE, unfortunately, does not allow you to query the contents of a directory.

If you’re on Oracle 11g you can use the method described here: listing files with the external table preprocessor in 11g.

If you’re on Oracle 10g another option is to create a java routine. Note: this is not my code – a colleague sent the basics to me and I just modified it somewhat to suit my purpose at the time.

CREATE OR REPLACE AND RESOLVE
JAVA SOURCE NAMED "DirectoryLister" AS
import java.io.File;
import java.util.Arrays;
public class DirectoryLister
{
  public static String getFileList(String idir, String sep)
  {
    File aDirectory = new File(idir);
    File[] filesInDir = aDirectory.listFiles();
    String result = "";
    for ( int i=0; i<filesInDir.length; i++ )
    {
        if ( filesInDir[i].isFile()
             && !filesInDir[i].isHidden() )
        {
            result = result + sep + filesInDir[i].getName();
        }
    }
    return result;
  }
};
/

CREATE OR REPLACE
FUNCTION dirlist_csv
(p_dir IN VARCHAR2, p_sep IN VARCHAR2) RETURN VARCHAR2
AS LANGUAGE JAVA NAME
'DirectoryLister.getFileList
  (java.lang.String, java.lang.String)
  return String';
/

BEGIN
  DBMS_JAVA.grant_permission('USER',
    'java.io.FilePermission', '<>', 'read');
  DBMS_JAVA.grant_permission('USER',
    'SYS:java.lang.RuntimePermission',
    'writeFileDescriptor', '');
  DBMS_JAVA.grant_permission('USER',
    'SYS:java.lang.RuntimePermission',
    'readFileDescriptor', '');
END;
/

(replace “USER” in the above commands with the user name)

CREATE OR REPLACE
FUNCTION get_path (dir IN VARCHAR2) RETURN VARCHAR2 IS
  o_path ALL_DIRECTORIES.directory_path%TYPE;
BEGIN
  SELECT directory_path INTO o_path
  FROM ALL_DIRECTORIES d
  WHERE  d.directory_name = dir;
  RETURN o_path;
END get_path;

Sample script:

DECLARE
  csv VARCHAR2(32767);
  filename VARCHAR2(1000);
BEGIN
  csv := dirlist_csv(get_path('MYDIR'), ',');
  LOOP
    EXIT WHEN csv IS NULL;
    filename := SUBSTR(csv, INSTR(csv, ',', -1) + 1);
    dbms_output.put_line(filename);
    csv := SUBSTR(csv, 1, INSTR(csv, ',', -1) - 1);
  END LOOP;
END;
/

Note: If the number of files is expected to be large, it would be better to get the java program to insert the file names into a global temporary table, then query that, instead of returning the list as a CSV string.


Purge all Recyclebins without SYSDBA

Want to purge all the recyclebins for all users in your database?

Can’t (or don’t want to) log in as each user individually to run this, one by one:

PURGE RECYCLEBIN

You could log in as SYSDBA and run:

PURGE DBA_RECYCLEBIN

But, what if you don’t have SYSDBA access? (Yes, this has happened to me, with a client-supplied VM – they told me the SYSTEM password but not the SYS password)

You can use the PURGE TABLESPACE x USER y option – run this to generate the commands to run, then run the output as a script:

SELECT DISTINCT
       REPLACE(REPLACE('PURGE TABLESPACE "#TS#" USER "#OWNER#";'
       ,'#TS#',ts_name)
       ,'#OWNER#',owner)
FROM dba_recyclebin
WHERE ts_name IS NOT NULL;
PURGE TABLESPACE "USER_DATA" USER "SCOTT";
PURGE TABLESPACE "USER_DATA" USER "LARRY";

WARNING: this command will result in irreversible loss of data for all users on your database.

Tested on Oracle 10gR2.


Forms Library: PKG_DEBUG

This is just a post to document a standard utility functions that I like to create in a Oracle Forms library, if equivalents are not already available. Suggestions or critiques are welcome.

“No warranty is express or implied about the suitability of this code for any purpose.”

This package could do with some improvements:

  • use a database table type (instead of one defined in the forms package) so that we can just send it straight to the database package

  • perhaps a “level” for each log message (Debug/Info/Warning/Error/Fatal) plus the ability to switch the level up or down for each session

Database Objects

CREATE TABLE DEBUG_LOG
(
  log_id      NUMBER(12,0)   NOT NULL
 ,ts          TIMESTAMP      NOT NULL
 ,text        VARCHAR2(4000)
 ,sid         NUMBER
    DEFAULT SYS_CONTEXT('USERENV','SID')
 ,sessionid   NUMBER
    DEFAULT SYS_CONTEXT('USERENV','SESSIONID')
 ,module      VARCHAR2(48)
    DEFAULT SYS_CONTEXT('USERENV','MODULE')
 ,action      VARCHAR2(32)
    DEFAULT SYS_CONTEXT('USERENV','ACTION')
 ,client_info VARCHAR2(64)
    DEFAULT SYS_CONTEXT('USERENV','CLIENT_INFO')
 ,username    VARCHAR2(30)
    DEFAULT SYS_CONTEXT('USERENV','SESSION_USER')
)
CREATE SEQUENCE DEBUG_LOG_SEQ;
CREATE OR REPLACE PACKAGE DB_FORMS_DEBUG IS

TYPE logtable_type IS TABLE OF VARCHAR2(4000)
  INDEX BY BINARY_INTEGER;
TYPE date_table_type IS TABLE OF DATE
  INDEX BY BINARY_INTEGER;

PROCEDURE msg
  (text IN VARCHAR2
  ,ts IN TIMESTAMP := NULL);

PROCEDURE insert_form_debug_log
  (logtable IN logtable_type
  ,date_table IN date_table_type
  ,username IN VARCHAR2
  ,module IN VARCHAR2
  );

END DB_FORMS_DEBUG;
CREATE OR REPLACE PACKAGE BODY DB_FORMS_DEBUG IS

PROCEDURE msg
  (text IN VARCHAR2
  ,ts IN TIMESTAMP := NULL) IS
PRAGMA AUTONOMOUS_TRANSACTION;
BEGIN
  FOR i IN 0 .. LENGTH(text) / 4000 LOOP
    INSERT INTO DEBUG_LOG
      (log_id
      ,ts
      ,text)
    VALUES
      (DEBUG_LOG_SEQ.NEXTVAL
      ,NVL(ts, SYSTIMESTAMP)
      ,SUBSTR(text, i * 4000 + 1, 4000));
  END LOOP;
  COMMIT;
END msg;

PROCEDURE insert_form_debug_log
  (logtable IN logtable_type
  ,date_table IN date_table_type
  ,username IN VARCHAR2
  ,module IN VARCHAR2
  ) IS
PRAGMA AUTONOMOUS_TRANSACTION;
BEGIN
  FORALL i IN logtable.FIRST..logtable.LAST
    INSERT INTO DEBUG_LOG
      (log_id
      ,ts
      ,text
      ,module
      ,username)
    VALUES
      (DEBUG_LOG_SEQ.NEXTVAL
      ,date_table(i)
      ,logtable(i)
      ,insert_form_debug_log.module
      ,insert_form_debug_log.username);
  COMMIT;
END insert_form_debug_log;

END DB_FORMS_DEBUG;

Form Package Specification

PACKAGE PKG_DEBUG IS

-- store the log contents in a database table, then reset the log
PROCEDURE flush_to_table;
-- debug log message
PROCEDURE msg (text IN VARCHAR2);
-- spit out debug info when an unexpected error ocurs
PROCEDURE on_error;
-- spit out debug info when a message is issued to the user
PROCEDURE on_message;
--popup a window showing the contents of the debug log
PROCEDURE show_log;
-- log current useful status info
PROCEDURE status;

END PKG_DEBUG;

Form Package Body

PACKAGE BODY PKG_DEBUG IS

-- the debug log is a circular buffer of debug log messages
TYPE debug_log_table_type IS TABLE OF VARCHAR2(4000) INDEX BY BINARY_INTEGER;
TYPE log_ts_table_type IS TABLE OF DATE INDEX BY BINARY_INTEGER;
con_debug_log_size CONSTANT PLS_INTEGER := 200;
debug_log_table debug_log_table_type;
log_ts_table log_ts_table_type;
debug_log_pos PLS_INTEGER;

PROCEDURE flush_to_table IS
-- send the debug log buffer to database table DEBUG_LOG
  c INTEGER := 0;
  i INTEGER := 1;
  logtable DB_FORMS_DEBUG.logtable_type;
  ts_table DB_FORMS_DEBUG.ts_table_type;
BEGIN
  LOOP
    EXIT WHEN i IS NULL;
    c := c + 1;
    logtable(c) := debug_log_table(i);
    ts_table(c) := log_ts_table(i);
    i := i + 1;
    --wrap to the top of the buffer
    IF i = con_debug_log_size THEN
      i := 1;
    END IF;
    EXIT WHEN i = debug_log_pos OR NOT debug_log_table.EXISTS(i);
  END LOOP;
  IF logtable.COUNT > 0 THEN
    --this log message will only survive if the db call fails
    DB_FORMS_DEBUG.insert_form_debug_log
      (logtable => logtable
      ,date_table => ts_table
      ,module => NAME_IN('SYSTEM.CURRENT_FORM')
      ,username => [user name/id...]);
    debug_log_table.DELETE;
    log_ts_table.DELETE;
    debug_log_pos := NULL;
  END IF;
END flush_to_table;

PROCEDURE msg (text IN VARCHAR2) IS
-- add debug log message to the scrolling log
BEGIN                              
  debug_log_pos := MOD(NVL(debug_log_pos,0) + 1, con_debug_log_size);
  debug_log_table(debug_log_pos) := SUBSTR(text,1,4000);
  log_ts_table(debug_log_pos) := PKG_FORM.system_datetime;
END msg;

PROCEDURE on_error IS
-- Catch-all error handler for unexpected errors.
BEGIN
  -- This should only ever be called when an *unexpected* error occurs.
  --
  -- If an error is expected in some circumstance, it should be handled (e.g. by putting
  -- code in the on-error trigger to do something intelligent instead of calling this
  -- catch-all procedure).
  --
  msg('DBMS ERROR    : ' || DBMS_ERROR_CODE || ' ' || RTRIM(DBMS_ERROR_TEXT,CHR(10)));
  status;
  flush_to_table; -- so that support personnel may investigate
  PKG_MESSAGE.error(ERROR_TYPE || '-' || ERROR_CODE || ' ' || ERROR_TEXT, 'System Error ' || ERROR_TYPE || '-' || ERROR_CODE);
END on_error;

PROCEDURE on_message IS
BEGIN
  status;
  MESSAGE(SUBSTR(MESSAGE_TYPE || '-' || MESSAGE_CODE || ' ' || MESSAGE_TEXT, 1, 200), ACKNOWLEDGE);
END on_message;

PROCEDURE show_log IS
  i INTEGER := debug_log_pos;
BEGIN
  -- fill the onscreen item CONTROL.DEBUGLOG starting
  -- with the most recent debug line, and go backwards until
  -- it is filled or there are no more debug log messages to show
  -- It would be better for this to be done in a separate
  -- form specifically for this purpose, to avoid problems
  -- when we want to show the debug log without
  -- firing validation triggers.
  :CONTROL.debuglog := NULL;
  LOOP
    EXIT WHEN i IS NULL;
      -- "64K should be enough for everybody"
      IF :CONTROL.debuglog IS NOT NULL THEN
        :CONTROL.debuglog := SUBSTR(CHR(10) || :CONTROL.debuglog, 1, 65534);
        EXIT WHEN LENGTH(:CONTROL.debuglog) = 65534;
      END IF;
      :CONTROL.debuglog := SUBSTR(
        TO_CHAR(i,'FM0000')
        || ' ' || TO_CHAR(log_ts_table(i),'HH24:MI:SS')
        || ' ' || debug_log_table(i)
        || :CONTROL.debuglog
        , 1, 65534);
      EXIT WHEN LENGTH(:CONTROL.debuglog) = 65534;
      i := i - 1;
      --wrap to the top of the buffer
      IF i = 0 THEN
        i := con_debug_log_size - 1;
      END IF;
      EXIT WHEN i = debug_log_pos OR NOT debug_log_table.EXISTS(i);
  END LOOP;
  GO_ITEM('CONTROL.debuglog');
  check_package_failure;
END show_log;

PROCEDURE status IS
BEGIN
  msg('FORM STATUS   : ' || :SYSTEM.FORM_STATUS);
  msg('RECORD STATUS : ' || :SYSTEM.RECORD_STATUS);
  msg('TRIGGER ITEM  : ' || NVL(:SYSTEM.TRIGGER_ITEM, :SYSTEM.TRIGGER_BLOCK)
    || ' RECORD #' || :SYSTEM.TRIGGER_RECORD);
  msg('CURSOR ITEM   : ' || :SYSTEM.CURSOR_ITEM
    || ' RECORD #' || :SYSTEM.CURSOR_RECORD);
END status;

END PKG_DEBUG;

Forms Library: General bits and pieces

This is just a post to document a standard utility functions that I like to create in a Oracle Forms library, if equivalents are not already available. Suggestions or critiques are welcome.

“No warranty is express or implied about the suitability of this code for any purpose.”

I’ll only create those things which I find become generally useful for a particular site. If something’s not used, get rid of it. That said, most of these things I’ve created because I use them frequently.

PROCEDURE assert (truth IN BOOLEAN, module IN VARCHAR2) IS
BEGIN
  IF truth THEN
    NULL;
  ELSE --truth may be null or false
    PKG_MESSAGE.error('Assertion failed in ' || module);
  END IF;
END assert;
PROCEDURE check_package_failure IS
-- (this is generated automatically by Oracle Forms when a block
-- relation is created)
-- This should be called after various builtins that, instead of
-- doing the honourable thing (raising an exception), set
-- FORM_SUCCESS. These builtins are*:
--  CALL_FORM CALL_QUERY CANCEL_QUERY CLEAR_BLOCK CLEAR_FORM
--  CLEAR_ITEM CLEAR_RECORD COUNT_QUERY DELETE_RECORD DOWN
--  DO_KEY DUPLICATE_ITEM DUPLICATE_RECORD EDIT_TEXTITEM ENTER
--  ENTER_QUERY EXECUTE_QUERY EXECUTE_TRIGGER EXIT_FORM
--  FETCH_RECORDS FIRST_RECORD FORMS_DDL GO_BLOCK GO_FORM
--  GO_ITEM GO_RECORD HOST INSERT_RECORD LAST_RECORD
--  LIST_VALUES LOCK_RECORD LOGON LOGON_SCREEN LOGOUT
--  NEW_FORM NEXT_BLOCK NEXT_ITEM NEXT_FORM NEXT_KEY
--  NEXT_RECORD NEXT_SET OPEN_FORM PREVIOUS_BLOCK
--  PREVIOUS_FORM PREVIOUS_ITEM PREVIOUS_BLOCK UP
-- * if you notice any builtins missing from, or that should not be
--    included in this list - please let me know!
BEGIN
  IF NOT ( Form_Success ) THEN
    RAISE Form_Trigger_Failure;
  END IF;
END check_package_failure;
PROCEDURE msg (text IN VARCHAR2) IS
-- just a convenient wrapper for PKG_DEBUG.msg
BEGIN
  PKG_DEBUG.msg(text);
END msg;

PKG_DEBUG definition

Form-level trigger: pre-select

msg(:SYSTEM.LAST_QUERY);

Form-level trigger: on-error

msg('on-error ' || ERROR_TYPE || '-' || ERROR_CODE || ' ' || ERROR_TEXT);
-- add handlers here for errors that we don't want to spit the dummy on (i.e. handle gracefully)
CASE
WHEN ERROR_TYPE||'-'||ERROR_CODE IN
  ('FRM-41105' --"You cannot query records without a saved parent record."
  ) THEN
  -- the default message is a little obtuse - give a standard response
  MESSAGE('That function is not allowed here.', ACKNOWLEDGE);
  RAISE FORM_TRIGGER_FAILURE;

WHEN ERROR_TYPE||'-'||ERROR_CODE IN
  ('FRM-40202' --"Field must be entered."
  ,'FRM-40203' --"Field must be entered completely."
  ,'FRM-40207' --"Must be in range x to y"
  ,'FRM-40209' --"Field must be of form x."
  ,'FRM-40212' --"Invalid value for field x."
  ,'FRM-40356' --"Invalid number in example record. Query not issued."
  ,'FRM-40357' --"Invalid string in example record. Query not issued."
  ,'FRM-40358' --"Invalid date in example record. Query not issued."
  ,'FRM-40359' --"Invalid date or time in example record. Query not issued."
  ,'FRM-40501' --"ORACLE error: unable to reserve record for update or delete."
  ,'FRM-40654' --"Record has been updated by another user. Re-query to see change."
  ,'FRM-40657' --"Record changed or deleted by another user."
  ,'FRM-41106' --"You cannot create records without a parent record."
  ) THEN
  -- show the error message in a popup and raise FTF
  PKG_FORM.error(ERROR_TEXT);

WHEN ERROR_TYPE||'-'||ERROR_CODE
  BETWEEN 'FRM-50000' AND 'FRM-51000' THEN
  -- almost all the FRM-5xxxx errors are to do with data format issues, e.g. date
  -- fields, numbers, etc
  PKG_FORM.error(ERROR_TEXT);

WHEN ERROR_TYPE||'-'||ERROR_CODE IN
  ('FRM-40100' --"At first record."
  ,'FRM-40102' --"Record must be entered or deleted first."
  ,'FRM-40110' --"At first block."
  ,'FRM-40111' --"At last block."
  ,'FRM-40200' --"Field is protected against update."
  ,'FRM-40201' --"Field is full. Can't insert character."
  ,'FRM-40401' --"No changes to save."
  ,'FRM-40405' --"No changes to apply."
  ,'FRM-41026' --"Field does not understand operation." (e.g. F9 on item with no list)
  ,'FRM-41050' --"You cannot update this record."
  ,'FRM-41051' --"You cannot create records here."
  ) THEN
  -- just display the default error message on the status bar (or popup if >1 message in quick succession)
  MESSAGE(ERROR_TEXT, ACKNOWLEDGE);
  RAISE FORM_TRIGGER_FAILURE;
ELSE
  PKG_DEBUG.on_error;
END CASE;

Form-level trigger: on-message

msg('on-message ' || MESSAGE_TYPE || '-' || MESSAGE_CODE || ' ' || MESSAGE_TEXT);
-- trap some messages and replace with more user-friendly message
CASE
WHEN MESSAGE_TYPE||'-'||MESSAGE_CODE IN
  ('FRM-40350' --"Query caused no records to be retrieved."
  ) THEN
PKG_FORM.note('No matching receipts found.', 'Search Results');
WHEN MESSAGE_TYPE||'-'||MESSAGE_CODE IN
  ('FRM-41800' --"List of Values not available for this field."
  ,'FRM-40400' --"Transaction complete: %s records applied and saved."
  ) THEN
  -- the default message is user-friendly enough to show on the status bar
  MESSAGE(MESSAGE_TEXT, ACKNOWLEDGE);
ELSE
  PKG_DEBUG.on_message;
END CASE;

Forms Library: PKG_MESSAGE

This is just a post to document the standard library that I like to create in Oracle Forms, if equivalents are not already available. Suggestions or critiques are welcome.

“No warranty is express or implied about the suitability of this code for any purpose.”

Forms Package Specification: PKG_MESSAGE

PACKAGE PKG_MESSAGE IS

PROCEDURE error
  (message IN VARCHAR2
  ,popup_title IN VARCHAR2 := 'Error');
PROCEDURE note
  (message IN VARCHAR2
  ,popup_title IN VARCHAR2 := 'Note');
PROCEDURE warning
  (message IN VARCHAR2
  ,popup_title IN VARCHAR2 := 'Warning');

END PKG_MESSAGE;

Forms Package Body: PKG_MESSAGE

PACKAGE PKG_MESSAGE IS

PROCEDURE error
  (message IN VARCHAR2
  ,popup_title IN VARCHAR2 := 'Error') IS
-- requires a suitable alert called "ERROR"
  n NUMBER;
BEGIN
  msg('PKG_MESSAGE.error('''||message||''','''||popup_title||''')');
  SET_ALERT_PROPERTY('ERROR', TITLE, popup_title);
  SET_ALERT_PROPERTY('ERROR', ALERT_MESSAGE_TEXT, message);
  n := SHOW_ALERT('ERROR');
  RAISE FORM_TRIGGER_FAILURE;
END error;

PROCEDURE note
  (message IN VARCHAR2
  ,popup_title IN VARCHAR2 := 'Note') IS
--requires a suitable alert "NOTE"
  n NUMBER;
BEGIN
  msg('PKG_MESSAGE.note('''||message||''','''||popup_title||''')');
  SET_ALERT_PROPERTY('NOTE', TITLE, popup_title);
  SET_ALERT_PROPERTY('NOTE', ALERT_MESSAGE_TEXT, message);
  n := SHOW_ALERT('NOTE');
END note;

PROCEDURE warning
  (message IN VARCHAR2
  ,popup_title IN VARCHAR2 := 'Warning') IS
-- requires a suitable alert "WARNING"
  n NUMBER;
BEGIN
  msg('PKG_MESSAGE.warning('''||message||''','''||popup_title||''')');
  SET_ALERT_PROPERTY('WARNING', TITLE, popup_title);
  SET_ALERT_PROPERTY('WARNING', ALERT_MESSAGE_TEXT, message);
  n := SHOW_ALERT('WARNING');
END warning;

END PKG_MESSAGE;

The Templating Way

Today, grasshopper, you will learn the Way of the Template. The Templating Way is the path by which complex output is produced in a harmonious fashion.

The Templating Way does not cobble a string together from bits and pieces in linear fashion.

htp.p('<HTML><HEAD><TITLE>'||:title
||'</TITLE></HEAD><BODY>'
||:body||'</BODY></HTML>');

The Templating Way separates the Template from the Substitutions; by this division is harmony achieved.

DECLARE
  template VARCHAR2(200)
  := q'[
       <HTML>
        <HEAD>
         <TITLE> #TITLE# </TITLE>
        </HEAD>
        <BODY> #BODY# </BODY>
       </HTML>
      ]';
BEGIN
  htp.p(
    REPLACE( REPLACE( template
    ,'#TITLE#', :title)
    ,'#BODY#',  :body)
    );
END;

It is efficient – each substitution expression is evaluated once and once only, even if required many times within the template.

The Templating Way makes dynamic SQL easy to write and debug. It makes bugs shallower.

SELECT REPLACE(REPLACE(REPLACE(q'[
  CREATE OR REPLACE TRIGGER #OWNER#.#TABLE#_BI
  BEFORE INSERT ON #OWNER#.#TABLE#
  FOR EACH ROW
  BEGIN
    IF :NEW.#COLUMN# IS NULL THEN
      SELECT #TABLE#_SEQ.NEXTVAL
      INTO :NEW.#COLUMN#
      FROM DUAL;
    END IF;
  END;
]', '#OWNER#', USER)
  , '#TABLE#', cc.table_name)
  , '#COLUMN#', cc.column_name) AS ddl
FROM user_constraints c, user_cons_columns cc
WHERE c.constraint_type = 'P'
AND c.constraint_name = cc.constraint_name
AND cc.column_name like '%NO';

The Templating Way is simple, but looks complex to the uninitiated. It is readable, and affords maintainability.


Current Record Visual Attribute problem

If you have a multi-record block, and you use the handy Current Record Visual Attribute (CRVA) to set, say, a different background colour on all the items in the currently selected record, you may have run into this problem.

If you want to conditionally switch the visual attribute for certain items, at the item instance (i.e. record) level, this causes the CRVA to be overwritten, and the current record won’t be consistently highlighted. To get around this problem, a bit more code is required.

For example, let’s say you have a multi-record block called EMP, and it has two items that are sometimes gray, sometimes white – SALARY and ROLE. You have defined the following visual attributes:
EDITABLE_ITEM – white background
READONLY_ITEM – gray background
CURRENT_RECORD – blue background

Package Specification

PACKAGE EMP_BLOCK IS
PROCEDURE highlight_current_record;
PROCEDURE when_clear_block;
PROCEDURE when_remove_record;
END EMP_BLOCK;

Package Body

PACKAGE EMP_BLOCK IS

record_highlighted INTEGER;

PROCEDURE highlight_current_record IS
  rec INTEGER := GET_BLOCK_PROPERTY('EMP', CURRENT_RECORD);
  PROCEDURE set_visattr
    (itemn IN VARCHAR2
    ,rec IN NUMBER
    ,visattr IN VARCHAR2) IS
  BEGIN
    IF visattr IS NULL THEN
      -- (we could, if needed, make this more intelligent about
      -- detecting whether the record is NEW/INSERT/CHANGED,
      -- and examine the INSERT_ALLOWED/UPDATE_ALLOWED
      -- properties accordingly)
      IF GET_ITEM_INSTANCE_PROPERTY
        (itemn
        ,record_highlighted
        ,UPDATE_ALLOWED) = 'TRUE' THEN
        set_visattr(itemn, record_highlighted, 'EDITABLE_ITEM');
      ELSE
        set_visattr(itemn, record_highlighted, 'READONLY_ITEM');
      END IF;
    ELSE
      SET_ITEM_INSTANCE_PROPERTY
        (itemn
        ,rec
        ,VISUAL_ATTRIBUTE
        ,visattr);
    END IF;
  END set_visattr;
BEGIN
  -- Note: if record_highlighted is null, then no record
  -- is currently highlighted
  IF rec != record_highlighted THEN
    --un-highlight the record that was highlighted
    set_visattr('EMP.SALARY', record_highlighted);
    set_visattr('EMP.ROLE', record_highlighted);
  END IF;
  --highlight the newly selected record
  set_visattr('EMP.SALARY', rec, 'CURRENT_RECORD');
  set_visattr('EMP.ROLE', rec, 'CURRENT_RECORD');
  record_highlighted := rec;
END highlight_current_record;

PROCEDURE when_clear_block IS
BEGIN
  record_highlighted := NULL;
END when_clear_block;

PROCEDURE when_remove_record IS
BEGIN
  IF record_highlighted = :SYSTEM.TRIGGER_RECORD THEN
    record_highlighted := NULL;
  END IF;
END when_remove_record;

END EMP_BLOCK;

Block-level triggers on EMP:

when-new-record-instance

EMP_BLOCK.highlight_current_record;

when-clear-block

EMP_BLOCK.when_clear_block;

when-remove-record

EMP_BLOCK.when_remove_record;

Also, whenever your code modifies the UPDATE_ALLOWED property on SALARY or ROLE, it must then call EMP_BLOCK.highlight_current_record again.


Forms Library: PKG_FORM

This is just a post to document a standard library that I like to create in Oracle Forms, if equivalents are not already available. Suggestions or critiques are welcome.

“No warranty is express or implied about the suitability of this code for any purpose.”

Specification

PACKAGE PKG_FORM IS

PROCEDURE centre_window (windown IN VARCHAR2);
PROCEDURE check_record_is_saved;
PROCEDURE commit;
FUNCTION current_record (blockn IN VARCHAR2) RETURN INTEGER;
FUNCTION current_record_status (blockn IN VARCHAR2) RETURN VARCHAR2;
PROCEDURE delay_action (timern IN VARCHAR2);
PROCEDURE set_current_record_status
  (blockn IN VARCHAR2
  ,istatus IN NUMBER);
PROCEDURE set_mdi_window_title (clock IN BOOLEAN := TRUE);

-- gets the date/time from the app server
FUNCTION system_datetime RETURN DATE;

END PKG_FORM;

Package Body

PACKAGE PKG_FORM IS

cAPP_TITLE CONSTANT VARCHAR2(100) := '[insert app title here]';

PROCEDURE centre_window (windown IN VARCHAR2) IS
  cMAIN_WINDOW CONSTANT VARCHAR2(100) := '[insert main window name here]';
  x NUMBER;
  y NUMBER;
  main_win WINDOW := FIND_WINDOW(cMAIN_WINDOW);
  window_id WINDOW := FIND_WINDOW(windown);
BEGIN
  x := GET_WINDOW_PROPERTY(main_win,X_POS)
     + (GET_WINDOW_PROPERTY(main_win,WIDTH )
        - GET_WINDOW_PROPERTY(window_id,WIDTH )) / 2;
  y := GET_WINDOW_PROPERTY(main_win,Y_POS)
     + (GET_WINDOW_PROPERTY(main_win,HEIGHT)
        - GET_WINDOW_PROPERTY(window_id,HEIGHT)) / 2;
  SHOW_WINDOW(window_id, x, y);
END centre_window;

PROCEDURE check_record_is_saved IS
BEGIN
  IF :SYSTEM.FORM_STATUS = 'CHANGED' THEN
    PKG_MESSAGE.error('Please save or cancel your changes first.');
  END IF;
END check_record_is_saved;

PROCEDURE commit IS
  msglevel VARCHAR2(2) := :SYSTEM.MESSAGE_LEVEL;
BEGIN
  msg('PKG_FORM.commit');
  -- set message level to avoid FRM-40401 "No changes to save."
  :SYSTEM.MESSAGE_LEVEL := '5';
  COMMIT_FORM;
  :SYSTEM.MESSAGE_LEVEL := msglevel;
  IF :SYSTEM.FORM_STATUS != 'QUERY' THEN
    PKG_MESSAGE.error('Unable to save changes.');
  END IF;
END commit;

FUNCTION current_record (blockn IN VARCHAR2) RETURN INTEGER IS
BEGIN
  RETURN GET_BLOCK_PROPERTY(blockn, CURRENT_RECORD);
END current_record;

FUNCTION current_record_status (blockn IN VARCHAR2) RETURN VARCHAR2 IS
BEGIN
  RETURN GET_RECORD_PROPERTY(
    GET_BLOCK_PROPERTY(blockn, CURRENT_RECORD),
    blockn,
    STATUS);
END current_record_status;

PROCEDURE delay_action (timern IN VARCHAR2) IS
-- requires a suitable WHEN-TIMER-EXPIRED form-level trigger
  timer_id TIMER;
BEGIN
  IF ID_NULL(FIND_TIMER(timern)) THEN
    msg('CREATE_TIMER('||timern||')');
    timer_id := CREATE_TIMER(timern,1,NO_REPEAT);
  END IF;
END delay_action;

PROCEDURE set_current_record_status
  (blockn IN VARCHAR2
  ,istatus IN NUMBER) IS
BEGIN
  SET_RECORD_PROPERTY(
     GET_BLOCK_PROPERTY(blockn, CURRENT_RECORD),
     blockn,
     STATUS,
     istatus);
END set_current_record_status;

PROCEDURE set_mdi_window_title (clock IN BOOLEAN := TRUE) IS
  --scaling factor is the number of milliseconds in a second
  cSCALING_FACTOR CONSTANT NUMBER := 1000;
  --don't update the time more than once every 10 seconds
  cMIN_UPDATE_FREQUENCY CONSTANT NUMBER := 10;
  date_time DATE;
  timer_id TIMER;
  seconds PLS_INTEGER;
  ms PLS_INTEGER;
BEGIN
  IF clock THEN
    date_time := system_datetime;
    SET_WINDOW_PROPERTY(FORMS_MDI_WINDOW, TITLE,
	        cAPP_TITLE || ' - '
	        || TO_CHAR(date_time,'Dy FMDD Mon YYYY HHFM:MIpm'));
    IF ID_NULL(FIND_TIMER('CLOCK')) THEN
      --get the seconds portion of the current time
      seconds := (date_time - TRUNC(date_time,'MI')) * 86400;
      --update the time at the end of the minute (or thereabouts)
      ms := GREATEST((61 - seconds) * cSCALING_FACTOR
	         ,cMIN_UPDATE_FREQUENCY * cSCALING_FACTOR);
      timer_id := CREATE_TIMER('CLOCK', ms, NO_REPEAT);
    END IF;
  ELSE
    SET_WINDOW_PROPERTY(FORMS_MDI_WINDOW, TITLE, cAPP_TITLE);
  END IF;
END set_mdi_window_title;

FUNCTION system_datetime RETURN DATE IS
-- gets the date/time from the app server
-- should perform better than calling SYSDATE all the time
-- WARNING: this assumes that the builtin date format includes the time component!
BEGIN
  RETURN TO_DATE(:SYSTEM.EFFECTIVE_DATE,
    GET_APPLICATION_PROPERTY(BUILTIN_DATE_FORMAT));
END system_datetime;

END PKG_FORM;

Example form-level trigger: when-timer-expired

DECLARE
  timern VARCHAR2(100) := GET_APPLICATION_PROPERTY(TIMER_NAME);
BEGIN
  msg('when-timer-expired ' || timern);
  CASE timern
    WHEN 'CLOCK' THEN
      PKG_FORM.set_mdi_window_title;
    WHEN 'PKGNAME_XYZ' THEN
      PKGNAME.xyz;
    -- ... etc. ...
  ELSE
    PKG_MESSAGE.error('Unexpected timer name: ' || timern, 'System Error');
  END CASE;
END;

Forms Library: PKG_ITEM

This is just a post to document a standard library that I like to create in Oracle Forms, if equivalents are not already available. Suggestions or critiques are welcome.

“No warranty is express or implied about the suitability of this code for any purpose.”

Specification
The main point of this package is to (a) easily make form items more proactive regarding business requirements, e.g. by making it simple to make items conditionally editable, readonly or mandatory; and (b) mitigate the pain of diagnosing bugs with the way items work (by logging when most of these procedures are called).

PACKAGE PKG_ITEM IS

-- set item to value, without changing item state if possible
PROCEDURE assign (itemn IN VARCHAR2, value IN VARCHAR2);

FUNCTION current_record (itemn IN VARCHAR2) RETURN INTEGER;
PROCEDURE disable_button (itemn IN VARCHAR2);
PROCEDURE enable_button (itemn IN VARCHAR2);
PROCEDURE go_next (itemn IN VARCHAR2);
PROCEDURE go_prev (itemn IN VARCHAR2);
PROCEDURE hide (itemn IN VARCHAR2);
FUNCTION is_navigable (itemn IN VARCHAR2) RETURN BOOLEAN;
PROCEDURE set_editable
  (itemn    IN VARCHAR2
  ,rec      IN INTEGER  := NULL
  ,editable IN BOOLEAN  := TRUE
  ,set_null IN BOOLEAN  := FALSE);
PROCEDURE set_readonly (itemn IN VARCHAR2, rec IN INTEGER := NULL);
PROCEDURE set_required (itemn IN VARCHAR2, rec IN INTEGER := NULL);
PROCEDURE set_valid (itemn IN VARCHAR2);
PROCEDURE set_visattr (itemn IN VARCHAR2, currec IN BOOLEAN);
PROCEDURE show (itemn IN VARCHAR2);

END PKG_ITEM;

Package Body

PACKAGE PKG_ITEM IS

cVISATTR_NORMAL CONSTANT VARCHAR2(100) := 'NORMAL_ITEM';
cVISATTR_CURRENT CONSTANT VARCHAR2(100) := 'CURRENT_RECORD';
cVISATTR_DISPLAY CONSTANT VARCHAR2(100) := 'DISPLAY_ITEM';
cVISATTR_REQUIRED CONSTANT VARCHAR2(100) := 'REQUIRED_ITEM';

PROCEDURE assign (itemn IN VARCHAR2, value IN VARCHAR2) IS
-- set item to value, without changing item state if possible
BEGIN
  IF NAME_IN(itemn) != value
    OR (NAME_IN(itemn) IS NULL AND value IS NOT NULL)
    OR (NAME_IN(itemn) IS NOT NULL AND value IS NULL) THEN
    PKG_DEBUG.msg(itemn || ':=' || value);
    COPY(value, itemn);
  END IF;
END assign;

FUNCTION current_record (itemn IN VARCHAR2) RETURN INTEGER IS
--gets the record number for the block for the given item
BEGIN
  RETURN GET_BLOCK_PROPERTY
    (SUBSTR(itemn,1,INSTR(itemn,'.')-1)
    ,CURRENT_RECORD);
END current_record;

PROCEDURE disable_button (itemn IN VARCHAR2) IS
BEGIN
  msg('PKG_ITEM.disable_button('||itemn||')');
  IF :SYSTEM.CURSOR_ITEM = UPPER(itemn) THEN
    DO_KEY('NEXT_ITEM');
    check_package_failure;
  END IF;
  SET_ITEM_PROPERTY(itemn, ENABLED, PROPERTY_FALSE);
END disable_button;

PROCEDURE enable_button (itemn IN VARCHAR2) IS
  item_id ITEM := FIND_ITEM(itemn);
BEGIN
  msg('PKG_ITEM.enable_button('||itemn||')');
  SET_ITEM_PROPERTY(item_id, ENABLED, PROPERTY_TRUE);
  SET_ITEM_PROPERTY(item_id, NAVIGABLE, PROPERTY_TRUE);
END enable_button;

PROCEDURE go_next (itemn IN VARCHAR2) IS
--This is used when doing a GO_ITEM in order to implement a NEXT_ITEM.
--This will issue a NEXT_ITEM if the item we've just gone to
--is not currently navigable on the current record.
BEGIN
  msg('PKG_ITEM.go_next('||itemn||')');
  GO_ITEM(itemn);
  check_package_failure;
  IF GET_ITEM_INSTANCE_PROPERTY(:SYSTEM.CURSOR_ITEM
	,GET_BLOCK_PROPERTY(:SYSTEM.CURSOR_BLOCK, CURRENT_RECORD)
	,NAVIGABLE) = 'FALSE' THEN
    NEXT_ITEM;
    check_package_failure;
  END IF;
END go_next_if_not_navigable;

PROCEDURE go_prev (itemn IN VARCHAR2) IS
--This is used when doing a GO_ITEM in order to implement a PREVIOUS_ITEM.
--This will issue a PREVIOUS_ITEM if the item we've just gone to
--is not currently navigable on the current record.
BEGIN
  msg('PKG_ITEM.go_prev('||itemn||')');
  GO_ITEM(itemn);
  check_package_failure;
  IF GET_ITEM_INSTANCE_PROPERTY(:SYSTEM.CURSOR_ITEM
	,GET_BLOCK_PROPERTY(:SYSTEM.CURSOR_BLOCK, CURRENT_RECORD)
	,NAVIGABLE) = 'FALSE' THEN
    PREVIOUS_ITEM;
    check_package_failure;
  END IF;
END go_prev_if_not_navigable;

PROCEDURE hide (itemn IN VARCHAR2) IS
BEGIN
  msg('PKG_ITEM.hide('||itemn||')');
  IF :SYSTEM.CURSOR_ITEM = UPPER(itemn) THEN
    NEXT_ITEM;
    check_package_failure;
  END IF;
  SET_ITEM_PROPERTY(itemn, VISIBLE, PROPERTY_FALSE);
END hide;

FUNCTION is_navigable (itemn IN VARCHAR2) RETURN BOOLEAN IS
BEGIN
  RETURN GET_ITEM_PROPERTY(itemn, NAVIGABLE) = 'TRUE';
END is_navigable;

PROCEDURE set_editable
  (itemn    IN VARCHAR2
  ,rec      IN INTEGER  := NULL
  ,editable IN BOOLEAN  := TRUE
  ,set_null IN BOOLEAN  := FALSE) IS
  item_id ITEM;
BEGIN
  msg('PKG_ITEM.set_editable('||itemn||','||rec||')');
  IF editable THEN
    item_id := FIND_ITEM(itemn);
    IF rec IS NULL THEN
      IF :SYSTEM.CURSOR_ITEM != UPPER(itemn) THEN
        SET_ITEM_PROPERTY(item_id, VISIBLE, PROPERTY_TRUE);
        SET_ITEM_PROPERTY(item_id, ENABLED, PROPERTY_TRUE);
      END IF;
      SET_ITEM_PROPERTY(item_id, NAVIGABLE, PROPERTY_TRUE);
      SET_ITEM_PROPERTY(item_id, INSERT_ALLOWED, PROPERTY_TRUE);
      SET_ITEM_PROPERTY(item_id, UPDATE_ALLOWED, PROPERTY_TRUE);
      SET_ITEM_PROPERTY(item_id, VISUAL_ATTRIBUTE, cVISATTR_NORMAL);
    ELSE
      SET_ITEM_INSTANCE_PROPERTY(item_id, rec, NAVIGABLE, PROPERTY_TRUE);
      SET_ITEM_INSTANCE_PROPERTY(item_id, rec, INSERT_ALLOWED, PROPERTY_TRUE);
      SET_ITEM_INSTANCE_PROPERTY(item_id, rec, UPDATE_ALLOWED, PROPERTY_TRUE);
      SET_ITEM_INSTANCE_PROPERTY(item_id, rec, VISUAL_ATTRIBUTE, cVISATTR_NORMAL);
    END IF;
  ELSE
    set_readonly(itemn, rec);
    --clear any data the user may have entered into the item (current record only)
    IF set_null AND NAME_IN(itemn) IS NOT NULL THEN
      msg(itemn||':=NULL');
      COPY(NULL, itemn);
    END IF;
  END IF;
END set_editable;

PROCEDURE set_readonly (itemn IN VARCHAR2, rec IN INTEGER := NULL) IS
  item_id ITEM := FIND_ITEM(itemn);
BEGIN
  msg('PKG_ITEM.set_readonly('||itemn||','||rec||')');
  IF rec IS NULL THEN
    SET_ITEM_PROPERTY(item_id, NAVIGABLE, PROPERTY_FALSE);
    SET_ITEM_PROPERTY(item_id, INSERT_ALLOWED, PROPERTY_FALSE);
    SET_ITEM_PROPERTY(item_id, UPDATE_ALLOWED, PROPERTY_FALSE);
    SET_ITEM_PROPERTY(item_id, VISUAL_ATTRIBUTE, cVISATTR_DISPLAY);
  ELSE
    SET_ITEM_INSTANCE_PROPERTY(item_id, rec, NAVIGABLE, PROPERTY_FALSE);
    SET_ITEM_INSTANCE_PROPERTY(item_id, rec, INSERT_ALLOWED, PROPERTY_FALSE);
    SET_ITEM_INSTANCE_PROPERTY(item_id, rec, UPDATE_ALLOWED, PROPERTY_FALSE);
    SET_ITEM_INSTANCE_PROPERTY(item_id, rec, VISUAL_ATTRIBUTE, cVISATTR_DISPLAY);
  END IF;
END set_readonly;

PROCEDURE set_required (itemn IN VARCHAR2, rec IN INTEGER := NULL) IS
BEGIN
  msg('PKG_ITEM.set_required('||itemn||','||rec||')');
  IF rec IS NULL THEN
    SET_ITEM_PROPERTY(itemn, REQUIRED, PROPERTY_TRUE);
    SET_ITEM_PROPERTY(itemn, VISUAL_ATTRIBUTE, cVISATTR_REQUIRED);
  ELSE
    SET_ITEM_INSTANCE_PROPERTY(itemn, rec, REQUIRED, PROPERTY_TRUE);
    SET_ITEM_INSTANCE_PROPERTY(itemn, rec, VISUAL_ATTRIBUTE, cVISATTR_REQUIRED);
  END IF;
END set_required;

PROCEDURE set_valid (itemn IN VARCHAR2) IS
BEGIN
  msg('PKG_ITEM.set_valid('||itemn||')');
  SET_ITEM_PROPERTY(itemn, ITEM_IS_VALID, PROPERTY_TRUE);
END set_valid;

PROCEDURE set_visattr (itemn IN VARCHAR2, currec IN BOOLEAN) IS
  rec INTEGER;
BEGIN
  msg('PKG_ITEM.set_visattr('||itemn||')');
  rec := item_current_record(itemn);
  IF currec THEN
    SET_ITEM_INSTANCE_PROPERTY(itemn, rec, VISUAL_ATTRIBUTE, cVISATTR_CURRENT);
  ELSE
    SET_ITEM_INSTANCE_PROPERTY(itemn, rec, VISUAL_ATTRIBUTE, cVISATTR_NORMAL);
  END IF;
END set_current_item_visattr;

PROCEDURE show (itemn IN VARCHAR2) IS
BEGIN
  msg('PKG_ITEM.show('||itemn||')');
  SET_ITEM_PROPERTY(itemn, VISIBLE, PROPERTY_TRUE);
END show;

END PKG_ITEM;

Example usage:

PKG_ITEM.set_editable('EMP.SALARY'
  ,rec      => PKG_FORM.current_record('MYBLOCK')
  ,editable => (:EMP.ROLE != 'CEO')
  );

The above example makes the SALARY item readonly if the employee’s role is ‘CEO’ – you would call this from the post-query trigger on the block, so on rows where the role is not ‘CEO’, SALARY will be editable.

Setting the visual attributes at the row level like this on multi-row blocks, however, has one side-effect. If you have a Current Record Visual Attribute (CRVA) set on the block (or the form), this code will overwrite that, so the CRVA will not be effective for these items. There is a workaround (to be published).


My favourite 11g thing

For too long I’ve muddled my way through using the built-in “explain plan” feature of the IDE-that-shall-remain-nameless provided by the client; but now that they’ve successfully upgraded from 9i to 11g, I’m now in a much better place. No longer will I wonder which table each step in a plan refers to, or what filters are being applied where.

DBMS_XPLAN is the best!

--get plan for a query
set pagesize 0 linesize 999 heading off feedback off echo on
explain plan for
SELECT bla FROM mytable WHERE bla;
set echo off
select * from table(dbms_xplan.display(format=>'ALL'));
--get plan for cursor in cache
set pagesize 0 linesize 999 heading off feedback off
select * from table(dbms_xplan.display_cursor(
sql_id=>'fnumywukcm2ng', cursor_child_no=> 0, format=>'ALL'));