pb_new2) Метод update объекта datawindow обновляет все данные вне зависимости были ли они изменены, или только измененные\добавленные в datawindow?

Вот из хэлпа:

When data is retrieved
When data is retrieved into a DataWindow, all rows and columns initially have a status of NotModified!.
After data has changed in a column in a particular row, either because the user changed the data or the data was changed programmatically, such as through the SetItem function, the column status for that column changes to DataModified!. Once the status for any column in a retrieved row changes to DataModified!, the row status also changes to DataModified!.

When rows are inserted
When a row is inserted into a DataWindow, it initially has a row status of New!, and all columns in that row initially have a column status of NotModified!. After data has changed in a column in the row, either because the user changed the data or the data was changed programmatically, such as through the SetItem function, the column status changes to DataModified!. Once the status for any column in the inserted row changes to DataModified!, the row status changes to NewModified!.

When a DataWindow column has a default value, the column's status does not change to DataModified! until the user makes at least one actual change to a column in that row.

When Update is called
A row's status flag determines what SQL command the Update function uses to update the database. INSERT or UPDATE is called depending upon the following row statuses:


A column is included in an UPDATE statement only if the following two conditions are met:

The column is on the updatable column list maintained by the DataWindow object

For more information about setting the update characteristics of the DataWindow object, see the PowerBuilder User's Guide.


The column has a column status of DataModified!

The DataWindow control includes all columns in INSERT statements it generates. If a column has no value, the DataWindow attempts to insert a NULL. This causes a database error if the database does not allow NULLs in that column.