SQL Server Convert Date Time to Date: A Complete Guide for Devs

Greetings, Dev! In this article, we’ll be discussing everything you need to know about converting date time to date in SQL Server. We know that working with dates and times can be a bit tricky, but we’ve got you covered. Let’s dive in!

Understanding Date Time and Date Data Types in SQL Server

Before we get to the conversion process, let’s first understand the two data types that we’ll be working with.

First up, we have the datetime data type. This data type stores both date and time values in a single field. The format for datetime data type is YYYY-MM-DD HH:MI:SS.

The second data type is date. As the name suggests, this data type stores only the date value. The format for date data type is YYYY-MM-DD.

Now that we know the difference between the two data types, let’s move on to the conversion process.

Converting Date Time to Date in SQL Server

There are multiple ways to convert date time to date in SQL Server. Let’s take a look at some of the most commonly used methods.

Method 1: Using CAST Function

The CAST function is used to convert one data type to another in SQL Server. We can use this function to convert a datetime value to a date value.

Original Value	Converted Value
2022-01-01 10:30:45	2022-01-01

To use the CAST function, we’ll need to specify the datetime value that we want to convert and the data type we want to convert it to.

Here’s an example:

SELECT CAST('2022-01-01 10:30:45' AS DATE);

This query will return the date value ‘2022-01-01’.

It’s important to note that the CAST function only works if the datetime value is in a valid format. If the datetime value is not in a valid format, we’ll need to use a different method to convert it to a date value.

Method 2: Using CONVERT Function

The CONVERT function is another way to convert a datetime value to a date value in SQL Server.

Here’s an example:

SELECT CONVERT(DATE, '2022-01-01 10:30:45');

This query will return the date value ‘2022-01-01’.

Similar to the CAST function, the CONVERT function only works if the datetime value is in a valid format.

Method 3: Using DATE Function

The DATE function is a newer function that was introduced in SQL Server 2012. This function can be used to extract the date value from a datetime value.

Here’s an example:

SELECT DATE('2022-01-01 10:30:45');

This query will return the date value ‘2022-01-01’.

The DATE function ensures that the datetime value is in a valid format before extracting the date value. This makes it a more reliable method compared to the CAST and CONVERT functions.

FAQs

Q: Can I convert a date value to a datetime value?

A: Yes, you can convert a date value to a datetime value using the CAST or CONVERT functions. Here’s an example:

SELECT CAST('2022-01-01' AS DATETIME);

This query will return the datetime value ‘2022-01-01 00:00:00’.

Q: What happens if the datetime value is in an invalid format?

A: If the datetime value is in an invalid format, the CAST and CONVERT functions will return an error. To avoid this, you can use the TRY_CAST and TRY_CONVERT functions instead. These functions will return NULL if the conversion fails.

Q: Can I convert a datetime value to a time value?

A: Yes, you can convert a datetime value to a time value using the CAST or CONVERT functions. Here’s an example:

SELECT CAST('2022-01-01 10:30:45' AS TIME);

This query will return the time value ’10:30:45′.

Conclusion

That’s it, Dev! We’ve covered everything you need to know about converting date time to date in SQL Server. We hope this article was helpful to you. If you have any questions or feedback, feel free to reach out to us. Happy coding!