It is now official - my friend Dietmar Aust is an Oracle ACE. Congratulations. Well deserved.
Saturday 1 December 2012
APEX - Statement of Direction
The new Statement of Direction is touching a couple of interesting things. Here are the three most important:
I think this is quite exciting and I can hardly wait to see it working. Theses are of course only the most important details. We will probably see a lot of other smaller things changing and improving.
I would like to add a couple of wishes to the list if not too late:
- New Multi-Row Edit Region Type – Define a new region type with a modern UI for updating multiple rows of data and allow multiple regions on one page
- Master / Detail / Detail – Provide a wizard interface to define declarative master/detail/detail regions.
- Multiple Interactive Reports – Allow any number of Interactive Reports to be defined on a single page.
I think this is quite exciting and I can hardly wait to see it working. Theses are of course only the most important details. We will probably see a lot of other smaller things changing and improving.
I would like to add a couple of wishes to the list if not too late:
- a wizard for creating tabular forms based on collections
- a wizard for creating single record forms managed by a procedure (package)
- an additional page element feature - update session state on change
- a new page element - simple checkbox
Monday 5 November 2012
Package for Creating Custom Code
Sometimes you will need to create your own processes for fetching values, validating and updating tables in a form. In some situations the wizard generated form will not be good enough to cover all you need. In that case you need to write your own code. Some programs like TOAD have a routine which generates update or delete procedures for you. However, you need to extend that and it is quite a bit of work. In my Demo Application I made the code available, which does almost all the work for you. This package has a couple of functions able to generate the code which requires only some minor changes. If you ever need to go away from the standard APEX form, you can do that this way:
1. Create the package "create_pkg_from_table" in your schema by running the code from the page I mentioned,
2. Create a form using wizard,
3. Remove the automatic processes and change the standard settings in the page items and use the following setting:
a) Set the "Source Used" to "Only when current..."
b) Set the "Source Type" to "Static Assignment..."
4. Create the custom package related to the table you reference in your form, for fetching, validating, updating and deleting records by running this SQL and executing the output:
1. Create the package "create_pkg_from_table" in your schema by running the code from the page I mentioned,
2. Create a form using wizard,
3. Remove the automatic processes and change the standard settings in the page items and use the following setting:
a) Set the "Source Used" to "Only when current..."
b) Set the "Source Type" to "Static Assignment..."
4. Create the custom package related to the table you reference in your form, for fetching, validating, updating and deleting records by running this SQL and executing the output:
SELECT create_pkg_from_table.create_package ('EMP', 'EMPNO', 1) FROM DUAL;5. Finally, run the following SQL to create the calls to the package functions and procedures you will need in your page processes and validations:
SELECT create_pkg_from_table.create_plsql_block ('EMP', 'EMPNO', 1) FROM DUAL;The only thing you need to do now is to format that code and paste it in the appropriate process.
Friday 26 October 2012
Goodbye apexblogs.info
http://www.apexblogs.info was a place I visited daily. A couple of days ago this domain was moved to http://www.odtug.com/apex. I am not sure I understand why but it doesn't matter. The only thing is that from the usability perspective this is now at least two steps back.
The current layout of the page is displaying a couple of logos, advertisements and some general information and the content is not in the focus - 75% of the page is not showing that, what you would actually expect. You need to scroll down to find the content and you need to scroll a lot. There are all together three scrollable regions including the page and if you don't watch you will easily loose the orientation.
Now, the question to ODTUG people would be if this is going to change in the near future. Hopefully there are plans to improve the usability of this popular resource. Otherwise the whole action doesn't make a lot of sense.
Sunday 14 October 2012
APEX Reporting on Comment Columns
This function may help you if you need to report on columns with a lot of text. It will get rid of the carriage return and will help not to break your reports imported into Excel:
CREATE OR REPLACE FUNCTION x_rep (p_string IN VARCHAR2) RETURN VARCHAR2 IS v_string VARCHAR2 (4000); BEGIN v_string := REPLACE (TRANSLATE (p_string, 'x' || CHR (10) || CHR (13), 'x'), ';', '/' ); RETURN v_string; EXCEPTION WHEN OTHERS THEN RETURN NULL; END x_rep; /
Monday 1 October 2012
My Demo Application
The link to My Demo Application on apex.oracle.com has been changed from
http://apex.oracle.com/pls/otn/f?p=31517:1
to
https://apex.oracle.com/pls/apex/f?p=31517:1
While trying to open the old link you will receive a funny message:
Sunday 2 September 2012
APEX 4.2
Today, apex.oracle.com was updated to 4.2. My first impression was good - I haven't seen the early adopter this time. If you have an account at apex.oracle.com you can have a look at the new layout of the apex builder. There are a lot of new features to explore in this version. The focus of this version is mobile development. Enjoy.
Sunday 26 August 2012
Highlight Search Term
APEX can highlight the search string in a report if you enter the substitution string in the column property of your report - Highlight Words. Unfortunatelly it will higlight the first occurence only. If you want to highlight more then only one occurence then you can use this function. The only limitation is the number of characters you can return per column (4000):
FUNCTION get_string_highlight (p_string IN VARCHAR2, p_highlight IN VARCHAR2) RETURN VARCHAR2 IS v_string VARCHAR2 (4000); v_substring VARCHAR2 (4000); v_trailingstring VARCHAR2 (4000); v_newstring VARCHAR2 (32000); v_position NUMBER := 0; v_length NUMBER := LENGTH (p_highlight); v_span_start VARCHAR2 (400) := '<span style="color:red;font-weight:bold">'; v_span_end VARCHAR2 (400) := '</span>'; BEGIN IF p_highlight IS NOT NULL THEN v_string := p_string; FOR i IN 1 .. 20 LOOP v_position := INSTR (UPPER (v_string), UPPER (p_highlight)); IF v_position > 0 THEN v_substring := SUBSTR (v_string, 1, v_position + v_length); v_substring := SUBSTR (v_string, 1, v_position - 1) || v_span_start || SUBSTR (v_string, v_position, v_length) || v_span_end; v_string := SUBSTR (v_string, v_position + v_length); v_newstring := v_newstring || v_substring; END IF; EXIT WHEN v_position = 0; END LOOP; v_newstring := v_newstring || v_string; ELSE v_newstring := p_string; END IF; RETURN v_newstring; END get_string_highlight;
Sunday 8 July 2012
Count Checked Rows in a Tabular Form
This is a quite simple but still frequently asked question. Here is an example on how to count checked rows in a tabular form. You may need this functionality prior to processing. For example, if you want to inform your user that they didn't select any rows after pressing the "Delete" button.
http://apex.oracle.com/pls/otn/f?p=31517:281
Thursday 28 June 2012
Text Area with Character Counter in a Tabular Form
This small example shows how to create a textarea in a tabular form with a character counter, similar to the one for the page item of type "Textarea":
http://apex.oracle.com/pls/otn/f?p=31517:276
APEX Tabular Form and ORA-01403: no data found
If you get the "ORA-01403: no data found" error after running your code while updating or validating a tabular form, you will need to find out which array is causing it. This error occurs if the referenced array does not exist - apex_application.g_f01..g_f50. For example, if you use a PL/SQL block similar to this:
1. Firefox
2. Firebug
Activate the firebug and use the HTML option to go over the elements (columns) in your tabular form. Firebug will show the associated array number and you can use that information to correct you code.
DECLARE vrow BINARY_INTEGER; BEGIN FOR i IN 1 .. apex_application.g_f01.COUNT LOOP vrow := apex_application.g_f01 (i); UPDATE dept SET dname = apex_application.g_f04 (vrow), loc = apex_application.g_f05 (vrow) WHERE empno = apex_application.g_f02 (vrow); END LOOP; END;The easiest way to debug is to use:
1. Firefox
2. Firebug
Activate the firebug and use the HTML option to go over the elements (columns) in your tabular form. Firebug will show the associated array number and you can use that information to correct you code.
Sunday 24 June 2012
Comparing Strings
I just received an interesting question regarding report filtering. The problem was the following:
1. There was a checkbox with multiple choices in the form.
2. The data would be saved as a concatenated string of values (String1:String2:String3).
3. The problem was in filtering that column since the filter would also be the same checkbox containing multiple values.
The solution for that is quite simple. All you need to do is to create a function which will compare the two strings and return something if it finds a match.
CREATE OR REPLACE FUNCTION compare_checkbox_strings ( p_checkbox IN VARCHAR2, p_column IN VARCHAR2 ) RETURN NUMBER IS l_vc_arr2 apex_application_global.vc_arr2; v_count NUMBER; BEGIN l_vc_arr2 := apex_util.string_to_table (p_checkbox); FOR i IN 1 .. l_vc_arr2.COUNT LOOP EXIT WHEN v_count > 0; v_count := INSTR (':' || p_column || ':', ':' || l_vc_arr2 (i) || ':'); END LOOP; IF v_count > 0 THEN RETURN 1; ELSE RETURN 0; END IF; END compare_checkbox_strings;Now, you can use it in your SQL Query like this:
SELECT * FROM your_table WHERE compare_checkbox_strings (:p1_your_checkbox, your_column) = 1;You can find a working example here: http://apex.oracle.com/pls/otn/f?p=31517:275
Monday 18 June 2012
BLOB over DB Link
Using a DB Link to query BLOB's from a remote database could be a problem. Recently, I had to show images comming from a remote server in an APEX application. Selecting from a remote table would result in an error. Creating a copy of the remote table by issuing the following statement worked without any problems:
After searching for a solution I found an interesting way to get it working:
Jiri's Microblog
Basically, all you need to do is to:
1. create a local copy of the table you get the data from as
2. create two types for storing the information
3. create a pipelined function to get the required row
Now, selecting from the function using the following SQL:
will get that BLOB for you.
INSERT INTO dbt_images SELECT * FROM dbt_images@remote_db WHERE ID = p_id;
After searching for a solution I found an interesting way to get it working:
Jiri's Microblog
Basically, all you need to do is to:
1. create a local copy of the table you get the data from as
CREATE TABLE dbt_images AS SELECT * FROM dbt_images@remote_db WHERE 1 = 2;
2. create two types for storing the information
CREATE OR REPLACE TYPE object_row_type AS OBJECT ( ID NUMBER, NAME VARCHAR2 (256), image BLOB, creator NUMBER, created DATE ); /
CREATE OR REPLACE TYPE object_table_type AS TABLE OF object_row_type; /
3. create a pipelined function to get the required row
CREATE OR REPLACE FUNCTION get_remote_blob (p_id IN NUMBER) RETURN object_table_type PIPELINED IS PRAGMA AUTONOMOUS_TRANSACTION; BEGIN INSERT INTO dbt_images SELECT * FROM dbt_images@remote_db WHERE ID = p_id; COMMIT; FOR cur IN (SELECT ID, NAME, image, creator, created FROM dbt_images) LOOP PIPE ROW (object_row_type (cur.ID, cur.NAME, cur.image, cur.creator, cur.created )); END LOOP; DELETE FROM dbt_images WHERE ID = p_id; COMMIT; RETURN; END get_remote_blob; /
Now, selecting from the function using the following SQL:
SELECT ID, image, NAME, DBMS_LOB.getlength (image) FROM TABLE (getblob (p_id));
will get that BLOB for you.
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