SQL Server Convert Date Time

Welcome, Dev! Date and time manipulation is an essential part of SQL Server development. The CONVERT function is a valuable tool that SQL Server provides for manipulating date and time data. In this article, we will explore the different methods to convert date and time data types in SQL Server.

Understanding Date and Time Data Types in SQL Server

Before we dive into converting date and time data types, it is essential to understand the different data types used in SQL Server for date and time.

SQL Server provides four different data types for date and time:

Keep in mind that the conversion methods we discuss in this article are specific to these data types. When working with other data types, you may need to use different conversion methods.

Converting Date and Time Data Types in SQL Server

1. Using CONVERT Function

The CONVERT function is used to convert one data type to another in SQL Server. When converting date and time data types, the CONVERT function can handle various formats and styles.

The following code demonstrates how to use the CONVERT function to convert a DATETIME value to a DATE value:

SELECT CONVERT(DATE, '2022-02-14 10:30:00', 120);

The result of the above code will be:

The above code uses the 120 format style to convert the DATETIME value ‘2022-02-14 10:30:00’ to a DATE value.

2. Using CAST Function

The CAST function is another way to convert one data type to another in SQL Server. When converting date and time data types, the CAST function can handle fewer formats and styles compared to the CONVERT function.

The following code demonstrates how to use the CAST function to convert a DATETIME value to a DATE value:

SELECT CAST('2022-02-14 10:30:00' AS DATE);

The result of the above code will be:

The above code uses the CAST function to convert the DATETIME value ‘2022-02-14 10:30:00’ to a DATE value.

3. Using DATEFROMPARTS Function

The DATEFROMPARTS function is used to create a DATE value from year, month, and day values.

The following code demonstrates how to use the DATEFROMPARTS function to create a DATE value:

SELECT DATEFROMPARTS(2022, 2, 14);

The result of the above code will be:

The above code uses the DATEFROMPARTS function to create a DATE value from year, month, and day values.

4. Using TIMEFROMPARTS Function

The TIMEFROMPARTS function is used to create a TIME value from hour, minute, second, and millisecond values.

The following code demonstrates how to use the TIMEFROMPARTS function to create a TIME value:

SELECT TIMEFROMPARTS(10, 30, 0, 0, 0);

The result of the above code will be:

The above code uses the TIMEFROMPARTS function to create a TIME value from hour, minute, second, and millisecond values.

FAQs

Q1.What is the difference between the CONVERT and CAST functions?

Both CONVERT and CAST functions are used to convert one data type to another in SQL Server. The main difference between the two functions is the number of formats and styles that they can handle. CONVERT function can handle more formats and styles than the CAST function.

Q2. Can I convert a DATE value to a DATETIME value?

Yes, you can convert a DATE value to a DATETIME value in SQL Server. You can use either the CONVERT function or the CAST function to perform this conversion.

Q3. Can I convert a STRING value to a DATE value?

Yes, you can convert a STRING value to a DATE value in SQL Server. You can use either the CONVERT function or the CAST function to perform this conversion.

Q4. Can I convert a TIME value to a DATETIME value?

No, you cannot convert a TIME value to a DATETIME value directly in SQL Server. However, you can combine a DATE value and a TIME value to create a DATETIME value.

Q5. What is the maximum and minimum date and time values that SQL Server can store?

The maximum and minimum date and time values that SQL Server can store vary by data type. DATETIME can store values ranging from January 1, 1753, through December 31, 9999. SMALLDATETIME can store values ranging from January 1, 1900, through June 6, 2079. DATE can store values ranging from January 1, 0001, through December 31, 9999. TIME can store values ranging from 00:00:00.0000000 through 23:59:59.9999999.

Conclusion

We hope this article has provided you with a better understanding of the different methods to convert date and time data types in SQL Server. Remember that the CONVERT and CAST functions offer different formats and styles, and the DATEFROMPARTS and TIMEFROMPARTS functions allow you to create date and time values from their individual parts. Keep these tools in mind when working with date and time data in your SQL Server development projects.