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Create Dates with Ease Using SQL Server’s DATEFROMPARTS() Function

SQL Server DATEFROMPARTS() Function: Creating Dates with Ease

Are you tired of manually constructing dates in SQL Server from separate year, month, and day values? Do you struggle with correctly formatting dates or dealing with NULL or out of range arguments?

Let the DATEFROMPARTS() function come to your rescue!

In this article, we will explore how the DATEFROMPARTS() function works, its syntax and return value, and how to use it for constructing dates in SQL Server. We will also provide examples of how to handle NULL and out of range arguments.

DATEFROMPARTS() Function Overview

The DATEFROMPARTS() function is a built-in date and time function in SQL Server that constructs a date value using separate year, month, and day values as arguments. It has the following syntax:

DATEFROMPARTS ( year, month, day )

The function returns a date value that represents the specified year, month, and day.

The return value is a date with a time value of 00:00:00. If the arguments are not valid, the function returns NULL.

The arguments for the DATEFROMPARTS() function must be integers. The year argument must be in the range from 1 to 9999, the month argument must be in the range from 1 to 12, and the day argument must be in the range from 1 to 31, depending on the month.

Let us look at an example of how to use the DATEFROMPARTS() function:

SELECT DATEFROMPARTS(2021,6,15)

The above query returns the date value ‘2021-06-15’. It is a simple way to construct dates in SQL Server.

DATEFROMPARTS() Function Examples

In the real world, you may encounter situations where the date arguments passed to the function are out of range or even NULL. In such cases, the function may not return the expected result, and an error may occur.

Let us look at some examples of how to handle such situations using the DATEFROMPARTS() function.

Constructing Date with NULL Argument

When one or more arguments to the DATEFROMPARTS() function is NULL, the function returns NULL. For example, the following query demonstrates:

SELECT DATEFROMPARTS(2021,NULL,15)

The above query returns NULL since the month argument is NULL.

In such cases, you can use the ISNULL() function or COALESCE() function to handle the NULL value. The following query returns the current date when the month argument is NULL:

SELECT DATEFROMPARTS(2021,ISNULL(NULL, MONTH(GETDATE())),15)

Constructing Date with Out of Range Argument

When one or more arguments to the DATEFROMPARTS() function is out of range, an error may occur. For example, the following query demonstrates:

SELECT DATEFROMPARTS(2021,2,31)

The above query generates an error message since the day argument is 31, which is out of range for February.

In such cases, you can use the TRY_PARSE() and TRY_CONVERT() functions to handle the error. The following query returns NULL when the day argument is out of range:

SELECT TRY_PARSE(‘2021-02-31’ AS DATE)

Using DATEFROMPARTS() Function with Shortcuts

The DATEFROMPARTS() function provides a shortcut to construct a date using fewer arguments. For example, you can omit the day argument and the function will default to the first day of the month.

Similarly, you can omit the month argument, and the function will default to January. The following query demonstrates:

SELECT DATEFROMPARTS(2021,6)

The above query returns ‘2021-06-01’.

You can use this shortcut to construct a date with either year and month or month and day arguments.

Conclusion

The DATEFROMPARTS() function is a powerful tool in SQL Server for constructing dates easily and efficiently. It is a simple function that requires only three arguments: year, month, and day.

However, it can cause errors when the arguments are out of range or NULL. In such cases, you can use functions such as ISNULL(), TRY_PARSE(), and TRY_CONVERT() to handle the issue.

With the knowledge gained from this article, you can now use the DATEFROMPARTS() function with ease and confidence in your SQL Server projects. In conclusion, the SQL Server DATEFROMPARTS() function is a vital tool for constructing dates by using separate year, month, and day values in SQL Server.

The function is easy to use and returns a date value representing the specified year, month, and day. However, you may encounter errors when the arguments are out of range or NULL.

By using functions such as ISNULL(), TRY_PARSE(), and TRY_CONVERT(), you can handle such issues. The DATEFROMPARTS() function shortcut can also be used for constructing a date with fewer arguments.

This knowledge can be useful in simplifying your SQL Server projects and making your work more comfortable, efficient, and error-free.

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