Month-until-date rolling calculation in BigQuery - google-bigquery

Can anyone help with calculating sales figures for month-until-date rolling sum on a data table carrying Datetime column and Sales figures column?
Using OVER in standard sql can help me calculate rows/dates preceding the current row, but I am having trouble with starting from day one of a month.

If you create columns for day, month, year (see:date extract function), you can use the month and year in the "PARTITION BY" part of your OVER function and the day in the "ORDER BY" part.
UPDATE
AliveToLearn worked it out: AVG(events_US) OVER (Partition by event_month, event_year ORDER BY day) AS moving_avg_month

Related

Write a SQL Query in Google Big Query which pulls all values from last week, all values from 2 weeks ago, and calculate percent change between them

I'm trying to query a table comparing order numbers from last week (Sunday to Saturday) vs 2 weeks ago, and calculate percent change between the two. My thought process so far has been to group my date column by week, then use a lag function to pull last week and the previous week in to the same row. From there use basic arithmetic functions to calculate percent change. In practice, I haven't been able to get a working query, but I picture the table to look as follows:
Week
Orders
Orders - Previous Week
% Change
2023-02-05
5
10
-0.5
2023-01-29
10
2
+5.0
2023-01-29
2
Important to note that the days in last week should not change regardless of what day it is today (i.e not use today -7 days to calculate last week, and -14 days to calculate 2 weeks ago)
My query so far:
SELECT
min(date) as date,
orders,
coalesce(lag(order) over (order by (date), 0)) as Orders - Previous Week
FROM `table`
WHERE date BETWEEN '2023-01-01' AND current_date()
group by date_trunc(date, WEEK)
ORDER BY date desc
I realize I'm not using coalesce and my lag function correctly, but a bit lost on how to correct it
To calculate the percent change, you can use the following query:
sql
Copy code
SELECT
min(date) as Week,
sum(orders) as Orders,
coalesce(sum(lag(orders) over (order by date_trunc(date, WEEK))), 0) as "Orders - Previous Week",
(sum(orders) - coalesce(sum(lag(orders) over (order by date_trunc(date, WEEK))), 0)) / coalesce(sum(lag(orders) over (order by date_trunc(date, WEEK))), 0) as "% Change"
FROM `table`
WHERE date BETWEEN '2023-01-01' AND current_date()
group by date_trunc(date, WEEK)
ORDER BY Week desc
In this query, the sum function is used to aggregate the orders by week. The coalesce function is used to handle the case where there is no previous week data, and default to 0. The percent change calculation uses the same formula you described.

Calculate Monthly Average With Multiple Records in a Month

I have a dataset with the structure below.
I want to calculate a monthly average of the views.
I attempted to calculate the yearly frequency with the following code and I believe it is correct
SELECT
EXTRACT (YEAR FROM TO_DATE("date",'Month YYYY') ) AS "year",
AVG("views")
FROM talks
GROUP BY EXTRACT (YEAR FROM TO_DATE("date",'Month YYYY') )
ORDER BY "year" DESC
When it comes to the monthly analysis I have the problem that there several records for the same month in a year and there several years with the same months (in reality the dataset has information for many years - this a reduced version).
How can I go to implement this?
If you want the average per month then just group by your current date field.
If you want the average per month regardless of year then you would have to extract the month part of the current date field and group by that.
But your date field now appears to be having string data type; it would be better to use proper date data type. Then your analysis would be much easier, more flexible, better performing.

BigQuery, Sum by week

I am using standard SQL and am trying to add the weekly sum for product usage by week.
Using code below, I was able to add to each row the respective week and year it falls into. How would I go about summing the totals for an item by week and outputting it in columns, say up to the last 8 weeks.
extract(week from Metrics_Date) as week, EXTRACT(YEAR FROM Metrics_Date) AS year
Image is my raw data with the week and year next to an item:
This image is of above raw data being analyzed further(grouping them together). Here is where I would want to add columns, current_week & firstday of week date, and a sum of that weeks totals.
Any help would be appreciated.
You don't need the extract() by the way, you can do truncation DATE_TRUNC(your_date, WEEK) and it will truncate it to the week, usually easier.
Also, because the result of the truncation is a date, you will have the first day of the week already.
The rest I believe you have it figured out already, but just in case:
SELECT DATE_TRUNC(your_date_field, WEEK) AS week, SUM(message_count) AS total_messages FROM your_table GROUP BY 1

How to get last and first date of every week from predefined date table (oracle SQL)

I have Table D_date in which all dates of a year, week number,quarter number etc attributes are defined. I just want to get first and last date of every week of year 2015.
Sample D_date tabe attached.
It is simple min/max if I understand you right
SELECT calendar_year_nbr, week, min(actual_date),max(actual_date)
FROM D_date
GROUP BY calendar_year_nbr, week
I just want to get first and last date of every week of year 2015.
Since you have precomputed values already stored in the table, you could directly use MIN and MAX as aggregate functions along with GROUP BY.
For example,
SELECT MIN(actual_date) min_date,
MAX(actual_date) max_date,
calendar_week_nbr
FROM d_date
WHERE calendar_year_nbr = 2015
GROUP BY calendar_week_nbr
ORDER BY min_date;
Another way is to use ROWNUM() OVER() analytic function.

Sql select statement that will bring back my data in weeks, using derived tables with JasperReports

I'm currently running the following sql statement in JasperReports Server to bring back my data using derived tables.
Select count(createddate) as ModulesCreatedDuringPastWeek,
count(updateddate) as ModulesUpdatedDuringPastWeek,
createddate,
updateddate
from merchendisingmodule
group by merchendisingmodule.createddate, merchendisingmodule.updateddate
However when grouping my data, I am only able to do it in Year, quarter, month and day. However for my report I'm needing the data to be group weeks, and so I was wondering what I will need to add to my code to do this.
DATEADD(D,-DATEPART(weekday,createddate)+1,createddate)
I use this method to prevent issues around the year transitions (week 53 in first days of januari and also in the last days of december, will group days together that are 360 days apart).
I use the first day of the week, instead of week numbers. I can use these dates to group by.
Also this will ensure that every week is 7 days long, instead of the last week of the year being only 3 or 4 days long.
Btw, in this example the first day of the week is sunday.
If your dates include time, use:
CAST(FLOOR(CAST(createddate AS FLOAT)) AS DATETIME)
instead of createddate in the above SYNTAX