Adventures in Machine Learning

Manipulating Dates and Times with SQL Server’s DATEPART() Function

As SQL developers, understanding how to manipulate dates and times is fundamental to working with any database management system. The SQL Server DATEPART() function allows us to extract specific date and time parts from a given input date, making it a crucial function for database manipulation.

SQL Server DATEPART() Function Overview

The DATEPART() function in SQL Server is used to extract specific date and time parts from a given input date. It takes two arguments: the date part (which is the specific date or time part to extract) and the input date (the date or time value from which the date part will be extracted).

Syntax of the DATEPART() Function

The syntax of the DATEPART() function looks like this:

DATEPART(date_part, input_date)

Where:

  • date_part: This is the specific date part to be extracted from the input_date argument. It can be any of the valid date parts (which we will discuss in the next section).
  • input_date: This is the date or time value from which the date_part argument will be extracted.

Valid Date Part Abbreviations

The DATEPART() function supports several valid date part abbreviations that can be used with the function. They include:

  • year (or yy, yyyy)
  • quarter (or qq, q)
  • month (or mm, m)
  • dayofyear (or dy, y)
  • day (or dd, d)
  • week (or wk, ww)
  • weekday (or dw)
  • hour (or hh)
  • minute (or mi, n)
  • second (or ss, s)
  • millisecond (or ms)
  • microsecond (or mcs)
  • nanosecond (or ns)

SQL Server DATEPART() Examples

Let’s look at some examples of how to use the DATEPART() function in SQL Server.

Example Using DATEPART() Function with Variables

DECLARE @input_date DATETIME2 = '2022-01-01 12:30:00';
DECLARE @year INT;
SET @year = DATEPART(year, @input_date);
SELECT @year AS [Year];

In this example, we declared a variable called @input_date and assigned it a DATETIME2 value of ‘2022-01-01 12:30:00’. We then declared another variable called @year, extracted the year from the @input_date variable using the DATEPART() function, and assigned it to the @year variable.

Finally, we selected the @year variable to display the result.

Example Using DATEPART() Function with Table Columns

SELECT YEAR(shipped_date) AS [Year], 
   DATEPART(quarter, shipped_date) AS [Quarter], 
   DATEPART(month, shipped_date) AS [Month], 
   DATEPART(day, shipped_date) AS [Day], 
   SUM(gross_sales) AS [Total Sales]

FROM sales
GROUP BY YEAR(shipped_date), 
   DATEPART(quarter, shipped_date), 
   DATEPART(month, shipped_date), 
   DATEPART(day, shipped_date);

In this example, we selected various date parts from the shipped_date column in the sales table and used them to group the results by year, quarter, month, and day. We also used the SUM() function to calculate the total gross sales for each date range.

Conclusion

In conclusion, the SQL Server DATEPART() function is a powerful tool for extracting specific date and time parts from an input date. By knowing the valid date part abbreviations and how to use the function with variables and table columns, SQL developers can manipulate data more effectively and efficiently.

We hope that this article has provided you with an informative overview of the DATEPART() function in SQL Server. In this article, we have explored the SQL Server DATEPART() function, which is used to extract specific date and time parts from an input date.

We looked at the syntax of the function, as well as the valid date part abbreviations, such as year, quarter, month, and day. We also provided examples of how to use the DATEPART() function with both variables and table columns.

Understanding how to manipulate dates and times is essential for any SQL developer, and the DATEPART() function can help us work with databases more effectively. By mastering this function, you will be able to extract the date parts you need and take your SQL development skills to the next level.

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