Time span accumulating fact tables design - data-warehouse

I need to design a star schema to process order processing. The progress of an order look like this:
Customer C place an order on item I with quantity 100
Factory F1 take the order partially with quantity 30
Factory F2 take the order partially with quantity 20
Buy from market 50 items
F1 delivery 20 items
F1 delivery 7 items
F1 cancel the contract (we need to buy 3 more item from market)
F2 delivery 20 items
Buy from market 3 items
Complete the order
How can I design a fact table in this case, since the number of step is not fixed, the data types of event is not the same.
I'm sorry for my bad English.

The definition of an Accumulating Snapshot Fact table according to Kimball is:
summarizes the measurement events occurring at predictable steps between the beginning and the end of a process.
For this particular use case I would go with a Transaction Fact Table as the events (steps) are unpredictable, it is more like an event fact table, something similar to logs or audits.
| order_key | date_key | full_datetime | entity_key (customer, factory, etc. varchar) | entity_type | state | quantity |
|-----------|----------|---------------------|----------------------------------------------|-------------|----------|----------|
| 1 | 20190602 | 2019-06-02 04:30:00 | C1 | customer | request | 100 |
| 1 | 20190602 | 2019-06-02 05:30:00 | F1 | factory | receive | 30 |
| 1 | 20190602 | 2019-06-02 05:30:00 | F2 | factory | receive | 20 |
| 1 | 20190602 | 2019-06-02 05:40:00 | Company? | company | buy | 50 |
| 1 | 20190603 | 2019-06-03 06:40:00 | F1 | factory | deliver | 20 |
| 1 | 20190603 | 2019-06-03 02:40:00 | F1 | factory | deliver | 7 |
| 1 | 20190603 | 2019-06-03 04:40:00 | F1 | factory | deliver | 3 |
| 1 | 20190603 | 2019-06-03 06:40:00 | F1 | factory | cancel | |
| 1 | 20190604 | 2019-06-04 07:40:00 | F2 | factory | deliver | 20 |
| 1 | 20190604 | 2019-06-04 07:40:00 | Company? | company | buy | 3 |
| 1 | 20190604 | 2019-06-04 09:40:00 | Company? | company | complete | 100 |
I'm not sure about your reporting needs as they were not specified, but assuming you need to measure lag/durations of unpredictable steps, you could PIVOT and use dynamic SQL to create the required view
SQL Server dynamic PIVOT query?
Let me know if you came up with something different as I'm interested on this particular use case. Good luck

Related

Union Vertical Blending in Data Studio

I want to blend several tables into 1 table. All of the tables have the same column so I'm thinking to UNION vertical all of the tables.
My data source is Google Sheets/ Spreadsheets.
The data will look like this:
Table1
| Type | Object | Amount |
|:---- |:---------:| ------:|
| Tech | PC | $100 |
| Tech | Keyboard | $50 |
| Tech | Mouse | $60 |
Table2
| Type | Object | Amount |
|:----- |:-----------------------:| ------:|
| Sales | Sales Incentives | $1000 |
| Sales | Meeting with Client | $400 |
| Sales | Visiting stores | $80 |
While the desired output would be:
| Type | Object | Amount |
|:----- |:-----------------------:| ------:|
| Sales | Sales Incentives | $1000 |
| Sales | Meeting with Client | $400 |
| Sales | Visiting stores | $80 |
| Tech | PC | $100 |
| Tech | Keyboard | $50 |
| Tech | Mouse | $60 |
If you can't see the table you can see the picture here
enter image description here
Anyone can help me with this? Thank you
I just got the the answer:
You can use the blending FULL OUTER JOIN and use the formula:
COALESCE(Name (Source #1),Name (Source #2),Name (Source #3))
You can see full information here
Thank you for Mehdi Oidjida for the help.

Rails Many to many relationships with connecting or cloning two table with references?

I'm a new with Rails and I'm having trouble with some types of associations that seem a bit more complex than the ones I've been exposed to so far.
Zombie_users Body_parts_status Body_parts
| id | name | | id | user_id | body_part_id | recovery | | id | name |
|-----------| --> |----------------------------------------| --> |---------------|
| 1 | Joe | | 1 | 1 | 2 | 10% | | 1 | left leg |
| 2 | Max | | 2 | 1 | 3 | 43% | | 2 | brain |
| 3 | hair |
| 4 | blue eye |
Zobmie_users Recovery_tools Body_parts_impacts
| id | name | | id |user_id| name | | id|recovery_tool_id| body_part_id | impact |
|-----------|-->|-------------------|-->|--------------------------------------------|
| 1 | Joe | | 1 | 1 |hammer| | 1 | 1 | 2 | 10% |
| 2 | Max | | 2 | 1 |magic | | 2 | 2 | 3 | 43% |
graphic illustration of the needed functionality
We have users and a list of body parts.
I need that the users will be able to create recovery tools with which they can through Body Parts impact recover their body parts status :)
and be able to check what part of the body still need to be fixed(compared to the list) and what body parts they have already corrected.
My problem is that I do not know how to implement such connections.
because I need to have some kind of clone of the body parts to body parts status for each user.
But how I reference it so it also works with Body Parts impacts
I do not have even a concept of where to start :)
body parts table is just a long listing of all the parts of the human body
and each user should have their own "copy" of all these parts.

How do you SUM two fields from two tables, even when the field in the second table could be null?

I have the following tables:
products.rb
# has_many :sales
+----+----------+----------+-------+
| id | name | quantity | price |
+----+----------+----------+-------+
| 1 | Pencil | 30 | 1.0 |
| 2 | Pen | 50 | 1.5 |
| 3 | Notebook | 100 | 2.0 |
+----+----------+----------+-------+
sales.rb
# belongs_to :product
+----+----------+------------+
| id | quantity | product_id |
+----+----------+------------+
| 1 | 10 | 1 |
| 2 | 2 | 1 |
| 3 | 5 | 1 |
| 4 | 2 | 2 |
| 5 | 10 | 2 |
+----+----------+------------+
I'd like to know, first, how many items I have left, regardless of their type. The answer is of course 151, but that'd be cheating. I could simply make a SUM of both tables individually, then put them together to know the final number, but I'm wondering if this could be done via activerecord in a single command.
I tried the following:
Product.includes(:sales).group('products.id').sum('products.quantity - sales.quantity')
but I get:
=> {1=>73, 2=>88, 3=>0}
which is understandable, as it is going through each one to do the sum like this:
+-------------------+----------------+-----+
| products.quantity | sales.quantity | sum |
+-------------------+----------------+-----+
| 30 | 10 | 20 |
| 30 | 2 | 28 |
| 30 | 5 | 25 |
+-------------------+----------------+-----+
which equals 73.
Anyway, how could this be achieved with ActiveRecord? I want to know the total number of items, but I'd also like to know the total of each type.
I'm not familiar of any ActiveRecord way to achieve what you want but you can try mixing a little sql in there
Product
.group('products.id')
.sum('products.quantity - (SELECT SUM(sales.quantity) AS sales_quantity FROM sales WHERE sales.product_id = products.id)')

Ideal solution for the following case scenario in database

There are 50 exams to be written by around millions of students online, One person may or may not write more than one exam. A person can also write a single exam more than one time ( retries ) ..
So which of the below solution is better for this case, I am okay with a better solution than these two as well
Option 1. Store each exam in a single table :
Subject 1
+----------------+---------+
| student id | Marks |
+----------------+---------+
| 1 | 85 |
| 2 | 32 |
| 2 | 60 |
+----------------+---------+
Subject 2
+----------------+---------+
| student id | Marks |
+----------------+---------+
| 1 | 85 |
| 2 | 32 |
| 2 | 60 |
+----------------+---------+
Like above with each table will have the student id only if that particular person has taken that exam , and have multiple occurrences of the student id if he has taken it more than once.
Option 2 :
+----------------+---------+---------+
| student id | Subject | Marks |
+----------------+---------+---------+
| 1 | Subj1 | 85 |
| 2 | Subj1 | 32 |
| 2 | Subj1 | 60 |
| 1 | Subj2 | 80 |
| 3 | Subj2 | 90 |
+----------------+---------+---------+
with all the values in a single table.
Which is better in terms of performance and storage perspective.
My various que
I think the best here is following:
Table STUDENT with information about students
Table EXAM with information about exams
Table EXAM_TRY with reference to STUDENT and EXAM tables, and fields DATE_OF_EXAM and RESULT_OF_EXAM
2 indexes on foreign keys in table EXAM_TRY
Depending on situation - index on date field (for example, you would need it for planning work for examiners)

SpecFlow - Repeat test X times with list?

Scenario: Change a member to ABC 60 days before anniversary date
Given Repeat When+Then for each of the following IDs:
| ID |
| 0047619101 |
| 0080762602 |
| 0186741901 |
| 0311285102 |
| 0570130101 |
| 0725968201 |
| 0780265749 |
| 0780265750 |
| 0780951340 |
| 0780962551 |
#-----------------------------------------------------------------------
When these events occur:
| WorkflowEventType | WorkflowEntryPoint |
| ABC | Status Change |
Then these commands are executed:
| command name |
| TerminateWorkflow |
And For Member, the following documents were queued:
| Name |
| ABC Packet |
In the above scenario I would like to:
GIVEN - Lookup 10 members from the DB
WHEN + THEN - Do these steps 10 times, once for each record.
Is this possible with SpecFlow?
If so, how would you set it up?
TIA
This is actually quite easy to do, although the documentation takes a bit of searching.
What you want is a scenario outline, like so:
Scenario Outline: Change a member to ABC 60 days before anniversary date
Given I have <memberId>
When these events occur:
| WorkflowEventType | WorkflowEntryPoint |
| ABC | Status Change |
Then these commands are executed:
| command name |
| TerminateWorkflow |
And For <memberId>, the following documents were queued:
| Name |
| ABC Packet |
Examples:
| memberId |
| 0047619101 |
| 0080762602 |
| 0186741901 |
| ...etc... |
This will execute your scenario once for each id in the examples table. You can extend the table to have multiple columns, if needed.
Or, more simply (if you really only have one row in each of your example tables above)
Scenario Outline: Change a member to ABC 60 days before anniversary date
Given I have <memberId>
When A 'ABC' Event Occurs with EntryPoint 'Status Change'
Then a TerminateWorkflow command is executed
And For <memberId>, the 'ABC Packet' document was queued
Examples:
| memberId |
| ...etc... |
For more information see the specflow-wiki on github and the cucumber language syntax for scenario outlines

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