24.4 Managing Legacy Tabular Forms

Tabular forms created using wizards include automatic DML processes. These wizards create a form that performs update, insert, and delete operations on multiple rows in a database table. Alternatively, you can build a tabular form manually either by creating a updatable report region or standard report region with updatable columns with custom PL/SQL page processes to process the tabular form data.

When running a tabular form, data is rendered as a report having updatable columns shown using various form elements (including text fields, text areas, date pickers, select lists, radio groups, and so on).

Description of the illustration GUID-DF73F35B-30C2-400A-BCBC-C5504DA571AF-default.png

By default, date columns are created using the Date Picker item type. If user interface defaults are defined, other columns can be automatically created as select lists based on lists of values, or numeric fields and large text areas.

For numeric and date fields, you can also pre-define date and number format masks, or apply those format masks after generating the initial form.

Each report also includes a check box column (called a row selector). Users use this row selector to select one or more columns and update or delete data. To add a row, users click Add Row.

Tabular forms are based on a SQL query in which the query columns are tied to the underlying table columns. Unlike a single record from, tabular forms do not store data in session state. When a tabular form page is submitted, the tabular form data is processed using built-in data manipulation language (DML), or a custom PL/SQL page processes.

A tabular form with automatic DML has two processes for multi-row operations:

• A Multi Row Update (MRU) process performs create and update operations.

• Multi Row Delete (MRD) process deletes requests on one or more rows.

MRU and MRD processes reference the underlying table name and the primary key columns. The primary key columns must be part of the tabular form SQL query, and the report columns must be either hidden or display-only (save state) in order for the DML processes to be able to identify the correct records. For new records, the primary key values must be NULL to be identified as new records. Delete operations are performed by referencing row number of the row to be deleted. Users can check one or more rows on the current page and when they click the Delete button, the row numbers identify the corresponding primary key value(s) and the matching rows are deleted.

Wizard generated tabular forms built-in DMLinclude a checksum column to prevent lost updates. Using a method called optimistic locking, a checksum is computed for each row when rendering a tabular form. This checksum is stored in an extra hidden tabular form column. Upon submission of the form for update, an additional set of checksums is computed on the then current data stored in the database. The new checksums are compared to those built when the tabular form was first rendered, and if there are any mismatches, the update is rejected, because the data in the database was either modified by another user or anther process in the time between the tabular form was rendered and the time the data was submitted.

Wizard generated tabular forms also automatically create validations for some columns. Validations are created for columns that are set to NOT NULL in the underlying table and columns of type NUMBER, DATE or TIMESTAMP. Note that validations are not created for columns if the column is set to read-only, either based on the user's selection, or defined user interface defaults.

1. On the Workspace home page, click the App Builder icon.
2. Select an application.
3. Click Create Page.
4. For Create a Page:
   1. User Interface - Select a user interface for the page.
   2. Select Legacy Page.
   3. Click Next.
5. Select Tabular Form and click Next.

   The Create Tabular Form Wizard appears.

6. For Page Attributes:
   1. Implementation - Select the report implementation type.
   2. Report Page Number - If you identify a new page number, the wizard creates a new page. If you identify an existing page number, the wizard adds the component to that page.
   3. Report Page Name - Enter the title of the page that will contain the report.
   4. Form Page Mode - Identify the page mode. See field-level Help for more information.
   5. Breadcrumb - Select whether you want to use a breadcrumb navigation control on your page, and which breadcrumb navigation control you want to use.
   6. Click Next.
7. For Navigation Menu, select how you want this page integrated into the Navigation Menu and click Next. See field-level Help for more information.
8. For Data Source:
   1. Table/View Owner - Select the table or view owner on which to base the tabular form.
   2. Table/View Name - Select the table or view which contains the columns to be included in the tabular form region.
   3. Select Column(s) to be shown in Report - Select one or more columns to be included in the tabular form. In the pages that follow you define which columns should be updatable.
   4. Click Next.

   Next, define a primary key. Tabular forms perform insert, update and delete operations on table rows in the database. You identify the rows by using either a primary key defined on the table, or the ROWID pseudo column, which uniquely identifies a row in a table.

9. For Form Page, select one of the following for Primary Key :

   • Managed by Database (ROWID) - The tabular form uses the ROWID pseudo column to identify rows to update and delete.

   • Select Primary Key Column(s) - The tabular form uses the source table's primary key column(s).

10. If you select Managed by Database (ROWID), click Next to continue.
11. If you select Select Primary Key Column(s):
    1. Primary Key Column 1 - Select the first column of the primary key.
    2. Primary Key Column 2 - If you have a compound primary key, specify the second primary key column in this attribute. This attribute is optional.
    3. For Source for Primary Key Column1, select the method by which the primary key is populated:

       • Existing trigger - Select this option if a before-insert trigger populates the primary key. You can also select this option if you plan on specifying the primary key column source later after completing the form.

       • Existing sequence - Select this option to pick the sequence from a list of sequences available in the selected schema.

    4. Click Create.

1. On the Workspace home page, click the App Builder icon.
2. Select the application.
3. Select a page containing the tabular form.
4. View the page in Component View.
5. To access the Report Attributes page, click the Report link next to the Tabular Form region.
6. From Tasks, select Synchronize Column Order with Region Source.
7. Click Synchronize.