I have these 2 tables and I need to create a relationship between them so that I can import them into SSAS Tabular and run some analysis.
The first table has RollingQuarter(Moving Quarter) data. The second is a basic Date table with Date as PK.
Can anyone suggest ways to create a relationship with these?
Ill be using SQL Server 2012.
I could re-create a new date table also.
I think you may have a rough time finding a relationship with these tables.
Your top data table is derived data. It's an average over three months, reported monthly. The Quantity column applies to that window, not to a particular date like all of the stuff in the second table. So what would any relationship really mean?
If you have the primary data that were used to calculate your moving average, then use those instead. Then you can relate dates between the two tables.
But if your analysis is such that you don't need the primary data for the top table, then just pick the middle of each quarter (March 15th 2001 for the first record) and use that as your independent variable for your time series on the top. Then you can relate them by that.
Related
I have a table "holidays" which represents people's holidays. It contains a FK to a person table, a from date column and a to date column. I want to add a constraint so that no person can have an over lapping holiday with themselves. So if Billy has a skiing holiday from 15th Jan - 20thJan, he can't have another vacation on the 18th Jan? But it's fine for him to do it on the 21st Jan?
Is this possible to do at database level via a constraint?
DB2 or Oracle can suffice?
Thanks
In DB2 you could use Temporal Tables and Time Travel Queries - check out the doumentation
Using Business Time with Business Period Temporal Tables will allow to define an index which enforces that periods do not overlap
CREATE UNIQUE INDEX I_vacation ON vacation (person, BUSINESS_TIME WITHOUT OVERLAPS)
Not directly. Constraints (at least in Oracle, I can't speak for other databases) work on one row at a time, they don't look at other rows - EXCEPT the UNIQUE constraint which looks across rows.
So - two solutions. One is, instead of storing ranges, to store one row per holiday DAY. (By the way, I believe what you call "holiday" is called "vacation", at least in America; "holiday" is reserved for common holidays, the same for all people, such as New Year or Christmas, etc.) In this arrangement, add a UNIQUE constraint on (person_id, vacation_day). Then re-work your input and reporting apps to translate from ranges to individual days, and respectively from individual days back to ranges.
The other solution, if you must store ranges, is to create a materialized view with refresh on commit (preferably fast refresh if the conditions permit), which shows person_id and vacation_day, one row per day - and put a UNIQUE constraint on the materialized view.
You can create a stored procedure wich take datestart and dateend of current row and use them parameter of this procedure. This procedure return 1 if exist in table a bad range and otherwise 0. Then you create your constraint check when this result procedure =0
I know there are a lot of solutions to this but I am looking for a simple query to get all the dates between two dates.
I cannot declare variables.
As per the comment above, it's just guesswork without your table structures and further detail. Also, are you using a 3NF database or star schema structures, etc. Is this a transaction system or a data warehouse?
As a general answer, I would recommend creating a Calendar table, that way you can create multiple columns for Working Day, Weekend Day, Business Day, etc. and add a date key value, starting at 1 and incrementing each day.
Your query then is a very simple sub-select or join to the table to do something like
SELECT date FROM Calendar WHERE date BETWEEN <x> AND <y>
How to create a Calender table for 100 years in Sql
There are other options like creating the calendar table using iterations (eg, as a CTE table) and linking to that.
SQL - Create a temp table or CTE of first day of the month and month names
I have a fact table that has 4 date columns CreatedDate, LoginDate, ActiveDate and EngagedDate. I have a dimension table called DimDate whose primary key can be used as foreign key for all the 4 date columns in fact table. So the model looks like this.
But the problem is, when I want to do sub-filtering for the measures based on the date column. For ex: Count all users who were created in the last month and are engaged in this month. This is not possible to do with this design, coz when I filter the measure with create date , I can’t further filter for a different time window for engaged date. Since all the connected to same dimension, they are not working independently.
However, If I create a separate date dimension table for each of the columns, and join them like this then it works.
But this looks very cumbersome when I have 20 different date columns in fact table in real world scenario, where I have to create 20 different dimensions and connect them one by one. Is there any other way I can achieve my scenario w/o creating multiple duplicated date dimensions?
This concept is called a role-playing dimension. You don't have to add the table to the DSV or the actual dimensions one time for each date. Instead add the date once, then go to the dimension usage tab. Click Add Cube Dimension, and then choose the date dim. Right-click and rename it. Then update the relationship to use the correct fields.
There's a good article on MSSQLTips.com that covers this topic.
Can Dimension Table became a fact table as well? For instance, I have a Customer dimension table with standard attributes such as name, gender, etc.
I need to know how many customers were created today, last month, last year etc. using SSAS.
I could create faceless fact table with customer key and date key or I could use the same customer dimension table because it has both keys already.
Is it normal to use Customer Dimension table as both Fact & Dimension?
Thanks
Yes, you can use a dimension table as fact table as well. In your case, you would just have a single measure which would be the count - assuming there is one record per customer in this customer table. In case you would have more than one record per customer, e. g. as you use a complex slowly changing dimension logic, you would use a distinct count.
Given your example, it is sufficient to run the query directly against the Customer dimension. There is no need to create another table to do that, such as a fact table. In fact it would be a bad idea to do that because you would have to maintain it every day. It is simpler just to run the query on the fly as long as you have time attributes in the customer table itself. In a sense you are using a dimension as a fact but, after all, data is data and can be queried as need be.
I am in a mission to devise an application database in MS ACCESS. In my database there are 5 tables:
Master
Cash
Cheque
Detail
Month (displays month in a year)
Here I have made Master as parent record and 3 others Cash, Cheque and Detail are children to Master table.
Here are the fields in master table
Lt no Name Regfee AssessmentYear April May June .......... March
The last 12 fields are months in a financial which takes amount as value.
These values should be populated from cheque/cash table through a query.
cheque
LTno **month** chqueno date bank **amount** are fields.
In this cheque table amount for a particular month is to be populated on master table for the corresponding month. What query do I make.
Expecting your valuable suggestions.
As the database is not normalised, you will have to make a very complicated query to update the table. You have to either make twelve updates that look almost the same, or a huge query that does almost the same thing twelve times.
It would be better to move the month values out of the master table and into a separate table where the month is a field in the table instead of a field name. Then it would be easy to add the records to it:
insert into MasterMonths (LTno, month, value)
select LTno, month, sum(amount)
from cheque
group by LTno, month
I do something similar, except that I include credit card slips and cash purchases as well as checks. It's basic bookkeeping.
For a variety of reasons, I chose to have a table called "almanac" with one row (record) for every date. There are columns (fields) for such things as day of the week, month of the year, and so on. I populate this table with a little code fragment written in VB. Even with ten years worth of dates, that's only about 3,653 rows in the table. I then use simple joins with this table to reduce transaction data to data that's summarized by month. I can summarize in other ways, too.
The query is so easy that I just did it with the graphical query interface. However, my summary would have twelve times as many rows as yours, with only one month in each row.
When I want data laid out in the format of your master table, I use one of two tools: the crosstab query tool in MS Access, or the Pivot Table tool in MS Excel. They are both very powerful, but the pivot tool is more flexible. I had to install an add in called MS query in Excel in order to query database data from Excel. That may be a function of the version I'm using.
This is very different from your framework, and it's your choice whether to use it. It's worked well for me.