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Unleashing the Power of SQL Server DATENAME() Function

SQL Server DATENAME() Function: A Comprehensive Guide

Have you ever found yourself trying to extract the day or month from a date in SQL Server? If yes, then you might want to try using the DATENAME() function.

This powerful function extracts date parts from an input date and returns the corresponding character string. In this article, we will explore the DATENAME() function in detail, including its syntax, date_part abbreviations, and differences from the DATEPART() function.

Additionally, we will provide an example usage of this function to help you understand it better.

Syntax of the DATENAME() function

The syntax of the DATENAME() function is straightforward. Here is a breakdown of the primary keywords:

  • DATENAME(): This is the function name that identifies it as the DATENAME() function.
  • string: This refers to the name of the date part that you want to extract from the input date. – NVARCHAR type: This is the data type that the function returns.
  • date part: This is a date or time element, such as year or hour, that you want to extract from the input date. – input_date: This is the date or time value that you want to extract the date parts from.

For instance, to extract the year from a date, you need to use this syntax:

DATENAME(string, input_date)

Date_part abbreviations

The DATENAME() function supports various date_part abbreviations that you can use to extract specific parts of the date. Here is a list of the most commonly used date_part abbreviations:

  • Year (yyyy, yy)
  • Quarter (qq, q)
  • Month (mm, m)
  • Day (dd, d)
  • Week (wk, ww)
  • Weekday (dw)
  • Hour (hh)
  • Minute (mi, n)
  • Second (ss, s)
  • Millisecond (ms)
  • Microsecond (mcs)
  • Nanosecond (ns)
  • TZoffset
  • ISO_WEEK (isowk)

These date_part abbreviations denote different elements of the input_date, and they can be used interchangeably with the string parameter in the DATENAME() function.

DATENAME() vs. DATEPART()

The DATENAME() function is often confused with the DATEPART() function in SQL Server.

While they both extract date parts from an input date and return an integer value, they differ in that the DATENAME() function returns a character string, while the DATEPART() function returns an integer. Here is an example of the date parts extraction using the DATENAME() function:

SELECT DATENAME(year, '2020-10-02 10:20:30.1234567 +08:10') as 'Year'
-- Returns '2020'

Here is an example of the date parts extraction using the DATEPART() function:

SELECT DATEPART(year, '2020-10-02 10:20:30.1234567 +08:10') as 'Year'
-- Returns 2020

Example usage of the DATENAME() function

Suppose you want to extract multiple date parts, such as year, month, and day, from a date. In that case, you can use the DATENAME() function to achieve this easily.

Here is an example that shows how to extract the year, month, and day from a date:

SELECT DATENAME(year, '2020-10-02 10:20:30.1234567 +08:10') as 'Year',
       DATENAME(month, '2020-10-02 10:20:30.1234567 +08:10') as 'Month',
       DATENAME(day, '2020-10-02 10:20:30.1234567 +08:10') as 'Day'
-- Returns Year: '2020', Month: 'October', Day: '02'

By combining multiple DATENAME() function calls on a single date, you can make it easier to extract specific parts of the date.

Conclusion

In conclusion, the DATENAME() function is a handy SQL Server function that makes it easier to extract specific parts of the date. By using the string parameter and date_part abbreviations, you can extract different date and time elements from the input date.

Additionally, by comparing it with the DATEPART() function, you can see how the DATENAME() function differs in its return data types. Finally, you can use an example to illustrate how to use the DATENAME() function to extract multiple date parts from an input date.

With this comprehensive guide, you can use the DATENAME() function in your SQL Server queries with confidence.

Recap of how to use the SQL Server DATENAME() Function

The SQL Server DATENAME() function is an essential feature that enables users to extract date parts from an input date. It is a powerful tool used in SQL Server for manipulating and analyzing data with dates and times.

Syntax of the DATENAME() function

The syntax of the DATENAME() function is straightforward, consisting of the function name, a string parameter, and an input date. The syntax is as follows:

DATENAME(string, input_date)

The string parameter refers to the specific date_part that you want to extract from the input date.

It is a character string and must be enclosed in quotes. The input_date parameter represents the date or time value that you want to extract the date part from.

It can be in any format, but it is recommended to use the international date format.

Date_part Abbreviations

The DATENAME() function supports various date_part abbreviations that you can use to extract specific parts of the input_date. The most commonly used date_part abbreviations are:

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

These date_part abbreviations denote different elements of the input_date, and you can use them interchangeably with the string parameter in the DATENAME() function.

For instance, to extract the year from an input date, you can use the abbreviation ‘year’ or ‘yyyy’ as follows:

SELECT DATENAME(year, '2022-11-10') AS 'Year'
-- Returns '2022'

SELECT DATENAME('yyyy', '2022-11-10') AS 'Year'
-- Also returns '2022'

Using the DATENAME() function with datetimeoffset Data Type

The datetimeoffset data type was introduced in SQL Server 2008 to store date and time values along with the offset from Coordinated Universal Time (UTC). If you want to extract the time zone information, you can use the TZoffset date_part abbreviation in the DATENAME() function.

SELECT DATENAME(tzoffset, '2022-11-10 16:12:30.1234567 +08:00') AS 'TimeZone'
-- Returns '+08:00'

The function returns the offset as ‘+hh:mm’ where ‘hh’ represents hours and ‘mm’ represents minutes.

Extracting Day Name and Month Name from Input Date

In addition to extracting date parts, the DATENAME() function can also extract the name of the day and month from the input date. The DATENAME() function returns a character string, so it can be used to extract the day name and month name.

SELECT DATENAME(weekday, '2022-12-04') AS 'DayName'
-- Returns 'Sunday'

SELECT DATENAME(month, '2022-12-04') AS 'MonthName'
-- Returns 'December'

By using the DATENAME() function, you can easily extract the name of the day or month from a given date.

Conclusion

In summary, the SQL Server DATENAME() function is a powerful tool for extracting date parts from an input date. You can use the function with various date_part abbreviations to extract date elements such as year, month, day, hour, and minute.

The function also supports extracting time zone information if you are working with the datetimeoffset data type. Additionally, the DATENAME() function can extract the name of the day and month from a given date.

By using this function, you can perform more complex date and time-related calculations and manipulations in your SQL Server queries with ease. In conclusion, the SQL Server DATENAME() function is a versatile tool that allows users to extract date parts from input dates with ease.

With the string parameter and date_part abbreviations, this function can extract various date/time elements such as year, month, day, hour, and minute. Additionally, it can extract the time zone information and the names of the day or month from a given date.

By using the DATENAME() function, you can perform more complex date and time-related calculations and manipulations in your SQL Server queries. It is a powerful feature that can save you time and effort.

Therefore, anyone working with SQL Server should take the time to learn and master this function.

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