I am working with a table containing the purchase history for a shop. There is a purchase id, a date column and a customer id. I am trying (without much success so far) to do two things:
Add a column which for each purchase tells how many purchases the customer made before this (in the last month). I started by joining the table on itself but haven't got much further. I know I'll need to somehow filter the date so it only counts purchases before this date and not more than a month ago. Any suggestions on a simple way to tackle this?
The second thing I would like to see is what the weekly rate of returning customer transactions is. That is, what proportion of the purchases are by someone who purchased recently (in the last month). Ideally I would be able to graph this so from my sql queries I would like to end up with a date, weekly total (the 7 days up to the date) and weekly rate. I have been reading up on rolling windows and to be honest am having a bit of trouble getting my head around it. My SQL level is still quite low unfortunately. Any tips on a relatively simple way to do this would be much appreciated.
Thanks
I would need to see your data structure for the table(s) to better answer your question. But right off the top of my head is seems like you just need a simple SELECT COUNT.
So something like this would return all transactions from a single customer made in the past month:
SELECT COUNT(purchase_id)
FROM purchases
WHERE customer_id='some_customer_id'
AND date >= DATEADD(m, -1, GETDATE());
As for your second question you would probably want to setup a job (jenkins, ect..) that would run a query every month. The results of which you would plot. Checkout https://oss.oetiker.ch/rrdtool/ for graphing
Related
I have a problem here, i would like to sum the work time from my employee based on the data (time2 - time 1) daily and here is my query:
Effective Minute Work Time = 24. * 60 * (LASTNONBLANK(time2,0) -FIRSTNONBLANK(time1,0))
It works daily, but if i drill up to weekly / monthly data it show the wrong sum as it shown below :
What i want is summary of minute between daily different times (time2-time1)
Thanks for your help :)
You have several approaches you can take: the hard way or the easier way :). The harder (at least for me :)) is to use DAX to do this. You would:
1) create a date table,
2) Use the DAX calculate function to evaluate your last non-blank and first non-blank values (you might need to use calculate table, but I'm not sure; DAX experts jump in). Then subtract one vs. the other.
This will give you correct values for a given day for a given person. You can enforce the latter condition by putting a 'has one value' guard on the person name so that your measure informs the report author if they're not using it right.
Doing the same for dates is a little trickier. In the example you show you are including the date in the row grouping. But if you change your mind and want instead to have 'total hours worked by person' or 'total hours worked by everyone' you're not done with modelling yet.
Your next step is to use calculate table in combination with calculate to create a measure that returns the total. You'll use calculate table so you evaluate each date and the hours worked on that date by person. Then you'll use calculate to summarize that all down to a single number. If you're not careful with your DAX (or report authoring) you might mix which person you're summarizing for so that your first/last non blank are not at the person level. It gets intense quickly.
Your easier solution, though it might be more limited in its application - depends really on your scenario - is to use the query to transform the data into a summary by day and person using the group by command. This will give you a row per person per day with their start and end times. Then you can quickly calculate the hours worked on that day. Then you can quite easily build visuals on top of the summary data. Of course you give up some of the flexibility of the having a proper data model. However if you have a date table, a person table, and your summary table and then setup your relationships correctly you can achieve answers to the most common questions.
Probably get shot for posting this again but last attempt was put on hold so sorry in advance. i am very new at this so apologies if its a simple answer;
I created a table with name of purchaser, items purchased, date of purchase and cost of purchase. From that i wanted to create a report that would show each purchasers name only once with a combined total cost of all purchases.
I created a query that did just that using only the purchasers name and the total cost of their purchases. I then created the report from that query.
The report shows each name once with a total cost of purchases which was great except for the query continually adds those total purchases without the ability to select a date range and likewise the report shows the same info.
When i add the purchased date to the query/report so i can filter between 2 date ranges it then shows each name "X" amount of times with a total for each purchase made which is not what i am looking for as this ends up with a long report.
Hope this makes more sense than my last attempt at this question. I am very new at this so a simple answer would be great.
Thanks in advance
You need to get two parameters for the query, say [Start] and [End].
You need to add the date column twice so that it can be compared to [Start] AND [End]
You need to add the date column (on both occasions) with a Total "Where"; this tells access that the column has no other purpose than to impact a WHERE-constraint on the base dataset.
If you run into trouble, take the SQL below, correct all names in it, paste it into the query's SQL view, and then see what the design view looks like!
SELECT table.customer, Sum(table.price) AS sum
FROM table
WHERE (((table.date)>=[Start]) AND ((table.date)<=[End]))
GROUP BY table.customer;
I implemented an own program to manage my incomes and expenses some years ago. However, I realized that I need some kind of "standing orders" - incomes or expenses which repeat monthly, quarterly or yearly. I would add them in an own table (with the value, description, start and end date, repetition rate, ...). But how do I query them with SQL/HQL in a smart way? For example: I want all incomes for a given month. Now I have to run through all entries and check somehow whether the start date plus a multiple of the repetition rate "hits" the current month. Seems to me very cumbersome. Is there an easy way to implement such operations?
Sorry for answering my own question, but in the meantime I think that it is not that difficult. Even when using HQL it is possible to calculate the number of months between two dates (if not with an existing function, it can still be done in the HQL expression using an obvious formula). Of course one has to handle the case correctly with days which exist in one month but not in the other (e.g., february), but this is a detail which can likely be ignored in my case.
Knowing the number of months between the current month, a simple modulo expression can check whether the current month is "hit" by the standing order. The rest is simple.
I have a 2 access 2007 tables with the following fields:
Table 1: Loan Release Table
ReleaseDate as Date
Maturity as Date
MemberName as Text
MemberNo as Text
Term (in months) as Number
Mode (M/Q/Semi-Monthly) as Text
LoanType as Text
LoanAmount as Currency
LoanCode as Text
Table 2: Payments Table
ReceiptNo as Text
DatePaid as Date
MemberName as Text
MemberNo as Text
LoanCode as Text
LoanReceivable as Currency
InterestPaid as Currency
I would like to ask on how to use Query to create a temporary table that will display Members that should pay on current date or a specified date base on their Term, Mode of Payment and Loan Type (Regular Loans every 30 days to pay, Special Loans every 45 days to pay) and their remaining balance.
Here's my First Attempted Query: I tried to subtract 30 days from Current Date and it obviously gave me just the transactions last month. I would like it to list all transactions including those for example Member with Regular Loan 12 month term on their 3rd monthly payment, Member with Special Loan that is due today.
I am thinking of creating another table that contains the schedule of payments of every Loan released and then go from there.
Is there another way than this? Like a Query that can be run everyday without the need for a bulky ScheduleOfPayments table?
I'm an office clerk who 'graduated' from Excel and a novice using Access at worst and I'm not afraid of VBA codes if that is necessary.
If you know of a better way of doing this, please do tell me or point me in the right direction. I'm all for learning new things and having read and learned a lot from stackoverflow before, I am sure that with your help, my question is as good as solved.
Thank you guys for reading my inquiry.
You have here two solutions:
You can write a procedure that will, when needed, calculate\generate a matrix containing payment schedule for each loan and compare it to payment done.
You can write a procedure that will, when a loan is created, generate corresponding records in a payment schedule table. further comparison will be done between the ScheduledPayment table and the Payment table.
So basically you have to manage a similar set of data, either as a calculated/on the fly matrix or as a permanent set of data kept in a table.
The second version is by very very far the most effective one. You think of it as bulky but it is exactly the opposite, and indeed what is done every time you get a loan from a bank, where your banker will let you sign the reimbursement schedule.
The table solution will allow you to make use of all querying facilities, while the calculated solution will force you to write specific procedures each time you'll want to do some data mining. Just think about a question like "What are the expected reimbursements for the month of April 2014?". Answering this question with the ScheduledPayment table will be as easy as getting a cafe out of your nespresso machine. The same answer without the ScheduledPayment table will be like having to do the whole coffee production process before getting your cup ready.
Suppose that I am using a sql server to keep track of all my personal expenses and that I am tagging everything with a date and a category.
This allows me to do things like aggregate monthly expenses per category and look at the last several months of expenses with each category as a row and the most recent months as columns.
What I am stuck on is the fact that I am having to name the columns things like "most recent month", "previous month", and "2 months ago". I would really prefer to be able to name them something like "Jan10", "Feb10", or "Mar09" or something like that and have them update automatically every month.
Calculating the names is simple enough, but I'm not sure how to get sql server to interpret a formula or join or anything like that as the alias for a column.
Any insights on this one?
What I am stuck on is the fact that I am having to name the columns things like "most recent month", "previous month", and "2 months ago". I would really prefer to be able to name them something like "Jan10", "Feb10", or "Mar09" or something like that and have them update automatically every month.
That approach means creating multiple columns, which will eventually hit the limit. In SQL Server, that's 1,024 for a non-wide and 30,000 for a wide table ...
A better approach is to store the date, and section/partition the data in the query as needed. Because Jan 10th is going to have a different value for 2009, 2010, 2011, etc...
It looks to me like you're trying to store data the same way you want to view it. That is not a very good way of going about it. I would suggest the following:
Your table should have the essentials, say:
Store (This could become its own table, but we can leave it as a string)
Category
Amount Spent
Date
Then, once you have this data, you can report on it. This report will do the heavy lifting, and will be dynamic in the sense that you don't need to hardcode values. The following is just an example, and I can't promise the syntax is even correct.
SELECT Store, SUM(CASE WHEN Date > GETDATE() - 14 THEN AmountSpent ELSE 0 END)
FROM YourTable
GROUP BY Store
The above will give you all money spent at each store in the last 14 days. This window will be "sliding", every time you run it, it will look back two weeks; no hardcoding.
You may wish to acquaint with Entity-attribute-value model and approaches.