Kexi/Plugins/Tables/Simple alter table

From KDE Community Wiki
< Kexi‎ | Plugins‎ | Tables

Design page for task: Simple approach to fulfill "Add support for alter table's design without losing data" wish.

Rationale

Approach when modification to table schema is saved directly after user performed it is much easier than full alter table tired in Kexi 1.x and never delivered.

Analysis

  • Altering some physical properties would require immediate saving of the design but will not remove all the data.
  • Other properties (for which KexiDB::isExtendedTableFieldProperty() return true) can be modified without altering any data.

Alter actions

This section publishes details on particular actions of table altering.

Caption rename

  • triggers name change in property editor, so:
    • A: if name changed, ask for accepting name change:
      • if accepted go to Name change section
      • if not accepted, revert the recent name change and go to B
    • B: else, do nothing, caption should be saved on Save action

Name change

  • can happen after change of caption (see Caption rename)
  • can happen after changed name value in the property editor
  • request instant applying
  • Algorithm:
    • ALTER TABLE available: send to the backend
    • ALTER TABLE not available:

use ALTER TABLE RENAME TO

Field removing

Field removing

Fields reordering

Field inserting

Requirements

  • Full data safety
    • It's better to warn and request data removal than claiming it is not necessary and then doing that

Links