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SQL Query: 3 Methods for Calculating Cumulative SUM

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SQL provides various constructs for calculating cumulative sums, offering flexibility and efficiency in data analysis. In this article, we explore three distinct SQL queries that facilitate the computation of cumulative sums. Each query leverages different SQL constructs to achieve the desired outcome, catering to diverse analytical needs and preferences. Using Window Functions (e.g., PostgreSQL, SQL Server, Oracle) SELECT id, value, SUM(value) OVER (ORDER BY id) AS cumulative_sum  FROM your_table; This query uses the SUM() window function with the OVER clause to calculate the cumulative sum of the value column ordered by the id column. Using Subqueries (e.g., MySQL, SQLite): SELECT t1.id, t1.value, SUM(t2.value) AS cumulative_sum FROM your_table t1 JOIN your_table t2 ON t1.id >= t2.id GROUP BY t1.id, t1.value ORDER BY t1.id; This query uses a self-join to calculate the cumulative sum. It joins the table with itself, matching rows where the id in the first table is greater than or

Python DateTime Objects: Manipulating and Calculating Dates

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Date and Time how to get and how to use is well needed in a software project. So in Python, you can find these features. Date and Time Features in Python Date feature you need it to get Date in the coding. Here the point is the Date and how to get it, and the various formats of it. Generally, you will find three different Date and Time formats. Before going into detail, here are those formats. Date and Time formats Epoch: It is a point where the time starts and is dependent on the platform. It is taken as January 1st of the current year, 00:00:00. But for UNIX systems, it is 1st January, 1970, 00:00:00 (UTC). UTC: UTC means Coordinated Universal Time (also known as Greenwich Mean Time) and is a compromise between English and French. DST: It is Daylight Saving Time which is an adjustment of the time zone by one hour during part of the year. In other words, the clock is forward by one hour in the spring and backward by one hour in the autumn to return to standard time. 1. How to get the