Default Frame Definitions
The default frame definition for an Append, Browse or Update frame contains the basic specifications that Vision needs to run the frame and to generate:
• The code for the frame, including:
– The database query for the frame
– The menu items to appear on the frame
• The form associated with the frame
The visual query window containing the default frame definition displays:
• The columns in the Master table
• The columns in the Detail table, if you have specified one
• The type of the Master and Detail tables (the table type corresponds to the frame type—Append, Browse, or Update)
The visual query window also displays these specifications of the default frame definition:
• The join columns between the Master and Detail tables
Vision draws a line between the first natural join (columns with the same name, data type and length) shared by the tables.
• The columns to include as fields on the frame's form and to use in the frame's database query
By default, Vision marks all columns with a "y" in the Display on Form field to indicate that it should generate fields on the form for these columns and include them in the query.
The only columns not marked as "y" are the join columns in the Detail table. You cannot display these columns as fields on the form, because they are duplicates of the same columns in the Master table.
• For Update frames, the default rules for inserting new records and deleting records. By default, Vision allows:
– Insertions in the Detail table
– Deletions in both the Master and Detail tables
Vision also sets the frame behaviors for Browse and Update frames as part of the default frame definition. The default frame behaviors are:
Qualification Processing
When a user runs the frame, the frame appears with a blank form; the user then can enter a query qualification to retrieve selected records.
Next Master Menu Item
Vision generates a Next menu item to let the user retrieve each record from the Master table (and corresponding records from the Detail table, if any) that satisfy the frame's query conditions.
The Next Master Menu Item frame behavior is not available if you have specified that the Master table appear as a table field.
For a description of how to modify any of the default frame definition specifications, see
Defining Frames with Visual Queries.
Default Transaction Processing
Vision-generated frames run in autocommit off mode. In Append frames, and Browse and Update frames that allow user qualifications, Vision inserts the following statements in the initialize block of the generated 4GL code:
commit work:
set autocommit off;
These statements are run before the form is displayed and before any Form-Start escape code is run. (For details on escape code, see
Using Vision Advanced Features.)
If an error occurs during a query when a generated frame is run, a rollback statement in the generated code causes any changes made since the last commit to be backed out.
Last modified date: 04/03/2024