To get the day of the year from a date in SQL, use the DATEPART function. This function takes two arguments: the first is the unit of time you want to get (in this case, the day of the year), and the second is the date you want to get the day of the year from. For example, if you wanted to get the day of the year from the date 2020-01-01, you would use the following query:
This query would return the result 1, since 2020-01-01 is the first day of the year.
Let's look at a few examples of how this function can be used. Suppose you have a table called orders with the following data:
If you wanted to get the day of the year for each order date, you would use the following query:
This query would return the results 1, 46, and 90, since those are the days of the year for the given order dates.
The DATEPART function is supported by most major databases, including MySQL, PostgreSQL, and SQL Server. However, the syntax may vary slightly depending on the database you are using. For more information, check out the documentation for your particular database.