Check Child Dependency

Question

I am looking for help writing an elegant t-sql query for following scenario:
In this scenario I have Task and TaskDependency tables. I would like to get a value of 1, 0, -1 based on the TaskStatus and TaskDependency table for each row in Task table. For example for TaskID = 1, there is no dependency in TaskDependency and Task Status
= 'Completed' it should return a value of 0. In case of Task.TaskID = 2 it should return value of -1. For Task.TaskID = 5 there is dependency on 2 and 4. Since 2 failed and 4 is completed it should still return value of 0.
Any help would be appreciated.
    Table: Task
    TaskID     TaskStatus
    1    Completed
    2    Failed
    3    Scheduled
    4    Scheduled
    5    Scheduled
    Table: TaskDependency
    TaskID    ParentTaskID
    1    NULL
    2    NULL
    3    2
    5    4
    4    NULL
    5    2
    Expected Result:
    Task.TaskID = 1 should return value of 0.
    Task.TaskID = 2 should return value of -1.
    Task.TaskID = 3 should return value of 0.
    Task.TaskID = 4 should return value of 1.
    Task.TaskID = 5 should return value of 0.

Answer 1

+In this scenario I have Task and Task_Dependencies tables. I would like to get a value of 1, 0, -1 based on the task_status  and Task_Dependencies table for each row in Task table. For example for task_nbr = 1, there is no dependency in Task_Dependencies
and Task Status = 'Completed' it should return a value of 0. In case of Tasks.task_nbr = 2 it should return value of -1. For Tasks.task_nbr = 5 there is dependency on 2 and 4. Since 2 failed and 4 is completed it should still return value of 0. 
Please post DDL, so that people do not have to guess what the keys, constraints, Declarative Referential Integrity, data types, etc. in your schema are. Learn how to follow ISO-11179 data element naming conventions and formatting rules. Tables are sets, so
their names are plural or (better) collective nouns. Temporal data should use ISO-8601 formats. Code should be in Standard SQL as much as possible and not local dialect. 
This is minimal polite behavior on SQL forums. Here is a correction on for your narrative description. A status is a “state of being” and has to have a duration; this is a basic concept of data modeling.
Please read this article: 
https://www.simple-talk.com/sql/t-sql-programming/state-transition-constraints/
The task dependencies are separate from the tasks and the particular job using the recipe, not blended into a mix of entities and relationships. Think of a recipe; it is a set of steps. It is not a particular meal, as you are doing. 
A forum is not a good place for this level of details. Do you know about PERT charts, Petri Nets or state transition diagrams? You will need extra states if some states require complicated precursors.  
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