SQL code for Weekly Sales Summary Report

This SQL code extract is designed to provide a summarized report of total sales per week. The code uses PostgreSQL's DATE_TRUNC function, JOIN operation, and aggregate functions like SUM.

Let's break this code down:

'SELECT' Clause

SELECT
    DATE_TRUNC('week', soh.orderdate) AS week_start_date,
    SUM(sod.orderqty * sod.unitprice) AS total_sales

This part of the code is responsible for defining which information will be extracted from the database.

• DATE_TRUNC('week', soh.orderdate) AS week_start_date: Here, the DATE_TRUNC function is used to get the first day of the week (by default Monday) from the orderdate. The 'week' parameter instructs the function to truncate the orderdate down to the week, effectively standardizing the time to the start of the week.

• SUM(sod.orderqty * sod.unitprice) AS total_sales: This calculates the total sales by multiplying orderqty and unitprice and then summarizing it with the SUM function.

'FROM' and 'JOIN' Clauses

FROM
    {{ Table("salesorderheader") }} soh
JOIN
    {{ Table("salesorderdetail") }} sod ON soh.salesorderid = sod.salesorderid

This part of the code indicates the source of the data needed for the retrieval operation.

• FROM {{ Table("salesorderheader") }} soh: This specifies that the data is being retrieved from the salesorderheader table. soh is an alias used for brevity.

• JOIN {{ Table("salesorderdetail") }} sod ON soh.salesorderid = sod.salesorderid: This statement joins the salesorderheader table with the salesorderdetail table based on the condition soh.salesorderid = sod.salesorderid.

'GROUP BY' and 'ORDER BY' Clauses

GROUP BY
    week_start_date
ORDER BY
    week_start_date;

• GROUP BY week_start_date: This statement organizes the selected data into groups by each week's start date. This is necessary for aggregate functions such as SUM to operate correctly.

• ORDER BY week_start_date;: Finally, the ORDER BY clause organizes the output rows by the week start date in ascending order.

Please note that {{ Table("") }} is a placeholder and it should be replaced with the actual table name, if you want to run the query in any SQL-based database management system.