I'm planning to create a dimension Location in my existing cube, based on a production database. The problem is that this database consists of a hierarchy with a selfreferencing object, a table called locations:
+----+----------+------------+
| id | parentId | name |
+----+----------+------------+
| 1 | NULL | Building A |
+----+----------+------------+
| 2 | 1 | Floor 1 |
+----+----------+------------+
| 3 | 2 | Room 11 |
+----+----------+------------+
| 4 | 2 | Room 12 |
+----+----------+------------+
| 5 | 2 | Room 13 |
+----+----------+------------+
| 6 | 1 | Floor 2 |
+----+----------+------------+
| 7 | 6 | Room 21 |
+----+----------+------------+
| 8 | 6 | Room 22 |
+----+----------+------------+
| 9 | NULL | Building B |
+----+----------+------------+
| 10 | 9 | Room 1 |
+----+----------+------------+
| 11 | 9 | Room 2 |
+----+----------+------------+
| 12 | 9 | Room 3 |
+----+----------+------------+
| 13 | NULL | Storage |
+----+----------+------------+
| 14 | NULL | Reception |
+----+----------+------------+
Normally I'd create a hierarchy like a date, the attribute month is a parent of attribute day and attribute year is a parent of attribute month. However, in this case the attribute Name from dimension Location could be the parent of another Name.
How can I create a hierarchy out of these records?
This is what Parent Child Hierarchies are meant for. See documentation.
Related
I have a JSON column containing col_values for another table. I want to return rows from that other table for each item in the JSON object.
If this was an INT column, I would use JOIN, but I need to JOIN every entry in the JSON object.
Take:
writers :
| id | name | projects (JSON) |
|:-- |:-----|:------------------|
| 1 | Andy | ["1","2","3","4"] |
| 2 | Hank | ["3","4","5","6"] |
| 3 | Alex | ["1","7","8","9"] |
| 4 | Joe | ["1","5","6","7"] |
| 5 | Ken | ["2","4","5","6"] |
| 6 | Zach | ["2","7","8","9"] |
| 7 | Walt | ["2","5","6","7"] |
| 8 | Mike | ["2","3","4","5"] |
cities :
| id | name | project |
|:-- |:---------|:--------|
| 1 | Boston | 1 |
| 2 | Chicago | 2 |
| 3 | Cisco | 3 |
| 4 | Seattle | 4 |
| 5 | North | 5 |
| 6 | West | 6 |
| 7 | Miami | 7 |
| 8 | York | 8 |
| 9 | Tainan | 9 |
| 10 | Seoul | 1 |
| 11 | South | 2 |
| 12 | Tokyo | 3 |
| 13 | Carlisle | 4 |
| 14 | Fugging | 5 |
| 15 | Turkey | 6 |
| 16 | Paris | 7 |
| 17 | Midguard | 8 |
| 18 | Fugging | 9 |
| 19 | Madrid | 1 |
| 20 | Salvador | 2 |
| 21 | Everett | 3 |
I need every city ordered by name for Mike (id=8).
Desired results:
This is what I'm getting and what I need to get (ORDER BY name).
Output :
| id | name | project |
|:---|:---------|:--------|
| 13 | Carlisle | 4 |
| 2 | Chicago | 2 |
| 3 | Cisco | 3 |
| 21 | Everett | 3 |
| 14 | Fugging | 5 |
| 5 | North | 5 |
| 20 | Salvador | 2 |
| 4 | Seattle | 4 |
| 11 | South | 2 |
| 12 | Tokyo | 3 |
Current query, but this can't be the best way...
SQL >
SELECT c.*
FROM cities c
WHERE EXISTS (
SELECT 1
FROM writers w
WHERE JSON_CONTAINS(
w.projects, CONCAT('\"', c.project, '\"'))
AND w.id = '8'
)
ORDER BY c.name;
DB Fiddle with the above. Is there a better way to do this "properly"?
Background
If it matters, I need to keep using JSON as the datatype because my server-side software that uses this database normally reads that column best if presented as a JSON object.
I would normally just do several database calls and iterate through that JSON object in my server-side language, but that is way too expensive with so many database calls, notwithstanding that it is even more costly to do multiple database calls for pagination.
I need all the results in a single database call. So, I need to JOIN or otherwise loop through each item in the JSON object within SQL.
Start with JOIN
Per a comment from a user, there is a better way...
SQL >
SELECT c.*
FROM writers w
JOIN cities c ON JSON_CONTAINS(w.projects, CONCAT('\"', c.project, '\"'))
WHERE w.id = '8'
ORDER BY c.name;
Output is the same...
Output :
id
name
project
13
Carlisle
4
2
Chicago
2
3
Cisco
3
21
Everett
3
14
Fugging
5
5
North
5
20
Salvador
2
4
Seattle
4
11
South
2
12
Tokyo
3
DB Fiddle
I'm designing a table for product categories for a kinda-e-commerce site. The table currently looks a bit like this:
| id | name | level | value | parent_id |
+----+-------------+-------+-------------+-----------+
| 1 | Food | 0 | food | NULL |
| 2 | Phone | 0 | phone | NULL |
| 3 | Thing | 0 | thing | NULL |
| 4 | Pasta | 1 | pasta | 1 |
| 5 | Apple | 1 | apple | 2 |
| 6 | SubThing | 1 | subthing | 3 |
| 7 | Tagliatelle | 2 | tagliatelle | 4 |
| 8 | iPhone 11 | 2 | iphone_11 | 5 |
| 9 | SubSubThing | 2 | subsubthing | 6 |
Basically I don't want to create a whole new table and map the relationships every time people want to add a new sub-level to the category structure, and rely on level and parent_id columns to let my code know how to do with this category and what its parent is. I'm completely new to model designing and this is the best I could come up with. Is there any downside to this self-referencing structure that I'm just too noob to realize?
If you are certain the sub level (child) will only ever be referenced by that single row or parent then the design should suffice. You may run into issues if multiple child elements need to roll up into that parent entity.
Please, tell me an example how to mark all the child nodes to the parent id. Only need to mark those branches whose parent has the value "need" (see example image). Using a recursive query, it is not possible to rename all the children of a particular parent...
Initial data:
+-----+----------+----------+
| id | parentid | selector |
+-----+----------+----------+
| 1 | | |
| 2 | 1 | |
| 3 | 1 | need |
| 4 | 2 | |
| 5 | 2 | need |
| 6 | 3 | |
| 7 | 5 | |
| 8 | 5 | |
| 9 | 6 | |
+-----+----------+----------+
Need data:
+-----+----------+----------+----------------+
| id | parentid | selector | parentSelector |
+-----+----------+----------+----------------+
| 1 | null | | null |
| 2 | 1 | | null |
| 3 | 1 | need | 3 |
| 4 | 2 | | null |
| 5 | 2 | need | 5 |
| 6 | 3 | | 3 |
| 7 | 5 | | 5 |
| 8 | 5 | | 5 |
| 9 | 6 | | 3 |
+-----+----------+----------+----------------+
The task is to make the grouping by those elements whose parent has the value "need". I think, I should create a column with a mark, as in the example in the table above, or are there any other options?
I use SQL Server 2012
I dont't know if it work on Sql server 2012, but i found this microsoft, i think is what you want, to make the parentSelector with condition, I use CASE (Transact-SQL).
This is another example: stackoverflow question
I have a master table (Project List) along with several sub tables that are joined on one common field (RecNum). I need to get totals for all of the sub tables, by column and am not sure how to do it. This is a sample of the table design. There are more columns in each table (I need to pull * from "Project List") but I'm showing a sampling of the column names and values to get an idea of what to do.
Project List
| RecNum | Project Description |
| 6 | Sample description |
| 7 | Another sample |
WeekA
| RecNum | UserName | Day1Reg | Day1OT | Day2Reg | Day2OT | Day3Reg | Day3OT |
| 6 | JustMe | 1 | 2 | 3 | 4 | 5 | 6 |
| 6 | NotMe | 1 | 2 | 3 | 4 | 5 | 6 |
| 7 | JustMe | | | | | | |
| 7 | NotMe | | | | | | |
WeekB
| RecNum | UserName | Day1Reg | Day1OT | Day2Reg | Day2OT | Day3Reg | Day3OT |
| 6 | JustMe | 7 | 8 | 1 | 2 | 3 | 4 |
| 6 | NotMe | 7 | 8 | 1 | 2 | 3 | 4 |
| 7 | JustMe | | | | | | |
| 7 | NotMe | | | | | | |
So the first query should return the complete totals for both users, like this:
| RecNum | Project Description | sumReg | sumOT |
| 6 | Sample description | 40 | 52 |
| 7 | Another sample | 0 | 0 |
The second query should return the totals for just a specified user, (WHERE UserName = 'JustMe') like this:
| RecNum | Project Description | sumReg | sumOT |
| 6 | Sample description | 20 | 26 |
| 7 | Another sample | 0 | 0 |
Multiple parallel tables with the same structure is usually a sign of poor database design. The data should really be all in one table, with additional columns specifying the week.
You can, however, use union all to bring the data together. The following is an example of a query:
select pl.recNum, pl.ProjectDescription,
sum(Day1Reg + Day2Reg + Day3Reg) as reg,
sum(Day1OT + Day2OT + Day3OT) as ot
from ProjectList pl join
(select * from weekA union all
select * from weekB
) w
on pl.recNum = w.recNum
group by l.recNum, pl.ProjectDescription,;
In practice, you should use select * with union all. You should list the columns out explicitly. You can add appropraite where clauses or conditional aggregation to get the results you want in any particular case.
Ok, so i have a bit of a complex query i am trying to come up with in my rails application. I have four tables: Clients, Projects, Invoices, Invoice_Line_Items. I am trying to get certain bits of data from all of those tables and display it in a "reports" type view in my application. This is what the structures look like for the four tables:
Clients
| id | name | archive |
----------------------------------------
| 1 | Client 1 | 0 |
| 2 | Client 2 | 0 |
Projects
| id | client_id | name | archive |
------------------------------------------------------
| 1 | 1 | Project 1 | 0 |
| 2 | 1 | Project 2 | 1 |
| 3 | 2 | Project 3 | 0 |
| 4 | 2 | Project 4 | 1 |
Invoices
| id | client_id | project_id | name | archive |
----------------------------------------------------------------------
| 1 | 1 | 1 | Invoice 1 | 0 |
| 2 | 1 | 1 | Invoice 2 | 0 |
| 3 | 1 | 2 | Invoice 3 | 1 |
| 4 | 1 | 2 | Invoice 4 | 1 |
| 5 | 2 | 3 | Invoice 5 | 0 |
| 6 | 2 | 3 | Invoice 6 | 0 |
| 7 | 2 | 4 | Invoice 7 | 1 |
| 8 | 2 | 4 | Invoice 8 | 1 |
Invoice_Line_Items
| id | invoice_id | name | amount_due |
---------------------------------------------------------
| 1 | 1 | Item 1 | 500 |
| 2 | 1 | Item 2 | 500 |
| 3 | 2 | Item 3 | 500 |
| 4 | 2 | Item 4 | 500 |
| 5 | 3 | Item 5 | 500 |
| 6 | 3 | Item 6 | 500 |
| 7 | 4 | Item 7 | 500 |
| 8 | 4 | Item 8 | 500 |
| 9 | 5 | Item 9 | 500 |
| 10 | 5 | Item 10 | 500 |
| 11 | 6 | Item 11 | 500 |
| 12 | 6 | Item 12 | 500 |
| 13 | 7 | Item 13 | 500 |
| 14 | 7 | Item 14 | 500 |
| 15 | 8 | Item 15 | 500 |
| 16 | 8 | Item 16 | 500 |
Ok, hope those diagrams make sense enough. What i am looking for as a result set is this (example data set taken from above example data):
| clients.name | current_projects | archived_projects | total_amount_due | total_amount_paid |
-----------------------------------------------------------------------------------------------------------
| Client 1 | 1 | 1 | 2000 | 2000 |
| Client 2 | 1 | 1 | 2000 | 2000 |
Ok, so here's what's going on there:
Getting all non-archived clients
Getting a count of all non-archived projects
Getting a count of all archived projects
Getting a total_amount_due from the invoice_line_items table that is a sum of all of the non-archived invoices
Getting a total_amount_paid from the invoice_line_items table that is a sum of all of the archived invoices
I am relatively new to Rails and this is a fairly complex query (at least in my head). Please let me know if there is a simpler solution that i am overlooking or if i am just over complicating it. If i need to do multiple queries in my controller that's fine, i was just wanting to see if i could get away with one sql call. I'm pretty sure i can do this pretty easily with some subqueries but i'm not sure how to write those in the controller in Rails.
Thanks for any help or direction you can provide and if this question is just outrageous or whatever just let me know and i'll delete it and go search the Googles more (have tried already to no avail).
Ok, well i ended up figuring out a solution myself. Not quite sure it's the best solution....feels heavy and messing but i just created quite a few objects in the controller to get the sql statements i needed to pull the data from the database. I basically have one object for each column (column, not each row). Let me know if anyone can figure out a better solution.