main_java
jeeeraaah datamodel
task and task group
The composition relation between TaskGroup and Task expresses, that at no time there is a Task that has no associated TaskGroup1.
//: # (TaskGroup “ 1” *-r “many” Task : “ tasks “)
tasks in detail
Tasks have a couple of relations to other Tasks as shown in the diagram below.
//: # (Task “ 1” *-> “ many” Task : children)
//: # (Task “ 1” *-> “ many” Task : predecessors)
//: # (Task “ 1” *-> “ many” Task : successors)
The fields are pretty self explaining. However there is one thing to mention with regard to the boolean field closed in Task. If it is true the fields start and end are no longer regarded as schedule information but as timestamps for the effective action carried out. Note that in general it is not assumed that the timestamps correspond to the effective amount of time the action required. It can be less than the period between the timestamps.
task object relations
| //: # (SubTask1 –u | > Task) |
| //: # (SubTask2 –u | > Task) |
| //: # (SubTask3 –u | > Task) |
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Technically there is a very short timed temporary exception from this constraint when a
Taskis to be deleted from persistent storage. ↩