Task list database table
From TaskDepender
(→Design) |
(→Design) |
||
| Line 26: | Line 26: | ||
The id of the current container can be retrieved by using the [[State variables database table]]. | The id of the current container can be retrieved by using the [[State variables database table]]. | ||
| − | When the table is created using the AS-SELECT statement, the constraint is not implemented yet. Therefore, after the table is created, the table must be [http://www.sqlite.org/lang_altertable.html altered] to create a reference to the original task in the [[ | + | When the table is created using the AS-SELECT statement, the constraint is not implemented yet. Therefore, after the table is created, the table must be [http://www.sqlite.org/lang_altertable.html altered] to create a reference to the original task in the [[Tasks database table|tasks table]]. The [www.sqlite.org SQLite] only supports a limited subset of [http://www.sqlite.org/lang_altertable.html ALTER TABLE] and it does not allow renaming or removing a column, or add or remove constraints from a table. Therefore, to implement the constraint, an additional column <tt>Parent</tt> is added that is referenced to the <tt>Id</tt> of the [[Tasks_database_table|tasks table]]. After creating this column, it must still be filled with the same value as the <tt>Id</tt>. |
== Implementation == | == Implementation == | ||
