Oracle Application - Alert

Every time you use the Alert manager to disable and enable an alert the database trigger associated with the alert got recreated and inside the database trigger there's a submit to a concurrent request to perform the actions associated with the alert.
You can check those concurrent request from the Alert Manager responsibility - Request - View.
If the alert action is not working check the parameters that passed to the concurrent request on the database trigger.

dividing by zero

If you are dividing to a column or sum in your select statement, and there's a chance that the column or the sum result might be a zero an error is going to occur on your select statement; to prevent the error and get a null result you can do the following

select sum(x)/sum(y) from dual; ----- result an error if sum(y) is zero

select sum(x)/decode (sum(y),0,null,sum(y)) from dual --- result is null if sum(y) is zero.

By using the decode, in case of zero the null is going to replace the zero or otherwise take the sum. dividing by null is null.

Graduation

I finally graduated from Marshall University www.marshall.edu college of information technology and engineering
I earned my masters degree in information systems after four years of part time study, full time employement and having two babies.

APEX Application Presentation

I presented my capstone project for defense. The project used Orace XE and APEX 3.2 to build a reference management system for students, faculty and researchers in a university environment. I'll post more about the application.

Making html button behave like hyperlink

I was trying to do so today for my eSurvey pages and I found it very simple

you just put the hyperlink before the button:



<p>
<a href="http://your link">
<input type="button" name="test">
</p>

Radio Group

• Radio groups are logical containers of radio buttons, so it doesn’t appear in the canvas only the radio buttons would appear in the canvas.
• Selection of one radio button deselects the previously selected button.
• To assign a NULL value, leave the radio button value property blank
• If the database column has a value that not one of the radio button value we should include this extra value in the Mapping OF Other values property even if it’s null otherwise when we execute query no records are returned.
• Can be database item or non-database item.

List Item

• Short list of values that the user can choose from.
• Once value can be selected.
• Can be a database or non-database item
• Each List Box must have an associated list of values (which can be hard-coded into the list box item, or dynamically attached from a Record Group).
• Properties:
• Element in list: the display value and database value pairs for the list.
• Mapping of Other Values Controls how records queried in the database will be handled if the value in the list column does not match the value of an item currently in the list.
• List item values: how each item in the list is represented in the database?
• Initial Value: must be one of list item values
• List Boxes come in several flavors
• Pop list the standard list box, which initially displays a single value that can be expanded to view the rest of the list
• T-List Can be sued when there are only a few items to display.
• Combo Box They are like the Pop list but they allow the user to type in a value that is not in the list and have that value saved to the database

Check Box

• Check boxes are useful for storing Yes/No, True/False, and On/Off-type values.
• It is not appropriate to use a check box to enable entry and update of more than two values in an item.
• Properties:
• Value when checked
• Value when unchecked
• Check box mapping of Other Values

Difference between LOV and list item

• LOVs open in a separate window , list items are positioned on a canvas
• LOVs are suited for many rows, list items should be limited to 15 rows.
• LOVs show multiple columns, list items show only one.

SHOW_LOV built in

SHOW_LOV built in is also used to display LOV , but its functionality is slightly different from the at of LIST_VALUES. It does not require that the LOV be attached to an item and it allows you to call an LOV explicitly by name.

LIST_VALUES built in

o LIST_VALUES displays the list of values for the current item, as long as the input focus is in a text item that has an attached LOV. Will only work if there is an LOV attached to the current item. The cursor must be in an item that has an LOV attached to it for LIST_VALUES to work. If we put LIST_VALUE inside when_button_presses an error is reported, if we want to put LIST_VALUES inside a button we need to have the Mouse Navigate Property set to NO so Oracle forms won’t perform navigation to the item when the end user activates the item with a mouse in this case of click on the button the triggers WHEN-BUTTON-PRESSED will fire but the input focus remains in the current item.
 It has the parameters NO_RESTRICT: Specifies that Oracle Forms will not use the automatic search and complete feature.
 Restrict: Specifies that Oracle Forms will use the automatic search and complete feature.

Set LOV properties

o Column Mapping Properties: Defines which columns will be displayed and each column’s return item (which item on the form the LOV column will populate_ and the width and title for the LOV column.
o Automatic Refresh Property: to refresh the record group data before displaying LOV.
o Filter Before display: If set to Yes, this property will present the user with a small filter window to let them filter the values returned to the LOV.
o Automatic Position property will positions the LOV just below the item that the LOV is attached to.