Date Convert in SQL Server

Hello Dev! Are you looking for ways to convert dates in SQL Server? You’ve come to the right place. In this article, we will explore the different ways to convert dates in SQL Server. We’ll cover everything from the basic syntax to advanced techniques. By the end of this article, you’ll be able to convert dates like a pro.

Introduction to Dates in SQL Server

In SQL Server, dates are stored as a number. The number represents the number of days since January 1, 1900. For example, January 1, 1900, is represented by the number 1. January 2, 1900, is represented by the number 2, and so on. SQL Server provides a set of functions that allow you to work with dates in a variety of formats.

The DATE Function

The DATE function is used to return the current date and time in SQL Server. The syntax of the function is as follows:

Function	Description
GETDATE()	Returns the current date and time

The GETDATE() function is commonly used in SQL Server to get the current date and time. It returns a datetime data type.

The following example shows how to use the GETDATE() function to get the current date and time:

SELECT GETDATE()

The result of the query will look like this:

Result
2021-06-10 12:34:56.789

You can also use the CURRENT_TIMESTAMP function to get the current date and time.

The CAST Function

The CAST function is used to convert a data type into another data type. It is commonly used to convert dates into different formats. The syntax of the function is as follows:

CAST(expression AS data_type)

The expression is the value you want to convert, and the data_type is the data type you want to convert it to. For example, if you want to convert a date into a varchar, you can use the following query:

SELECT CAST(GETDATE() AS varchar)

The result of the query will look like this:

Result
Jun 10 2021 12:34PM

You can also use the CONVERT function to convert dates into different formats.

Working with Dates in SQL Server

Formatting Dates

In SQL Server, you can use the CONVERT or FORMAT function to format dates into different formats. The syntax for the CONVERT function is as follows:

CONVERT(data_type, expression, style)

The data_type is the data type you want to convert the expression to, and the style is the style code that specifies the format of the date. For example, if you want to convert a date into a varchar in the format of YYYY-MM-DD, you can use the following query:

SELECT CONVERT(varchar, GETDATE(), 23)

The result of the query will look like this:

Result
2021-06-10

The FORMAT function works in a similar way to the CONVERT function. The syntax for the FORMAT function is as follows:

FORMAT(expression, format)

The expression is the date you want to format, and the format is the format you want to use. For example, if you want to format a date into the format of dd/MM/yyyy, you can use the following query:

SELECT FORMAT(GETDATE(), 'dd/MM/yyyy')

The result of the query will look like this:

Result
10/06/2021

Extracting Parts of Dates

In SQL Server, you can use the DATEPART function to extract specific parts of a date. The syntax of the function is as follows:

DATEPART(datepart, date)

The datepart is the part of the date you want to extract, and the date is the date you want to extract from. For example, if you want to extract the year from a date, you can use the following query:

SELECT DATEPART(year, GETDATE())

The result of the query will look like this:

Result
2021

You can also use the YEAR, MONTH, and DAY functions to extract the year, month, and day from a date, respectively.

Adding and Subtracting Dates

In SQL Server, you can use the DATEADD function to add or subtract a certain amount of time from a date. The syntax of the function is as follows:

DATEADD(datepart, number, date)

The datepart is the part of the date you want to add or subtract from, the number is the amount of time you want to add or subtract, and the date is the date you want to add or subtract from. For example, if you want to add 1 month to a date, you can use the following query:

SELECT DATEADD(month, 1, GETDATE())

The result of the query will look like this:

Result
2021-07-10 12:34:56.789

You can also use the DATEDIFF function to calculate the difference between two dates.

FAQs

What is the default date format in SQL Server?

The default date format in SQL Server is YYYY-MM-DD HH:MI:SS.

How do I convert a date into a specific format?

You can use the CONVERT or FORMAT function to convert a date into a specific format. The syntax for the functions are as follows:

CONVERT(varchar, GETDATE(), format_code)

FORMAT(GETDATE(), 'format_code')

The format_code is the code that specifies the format you want to use.

How do I extract the year from a date?

You can use the DATEPART function to extract the year from a date. The syntax of the function is as follows:

DATEPART(year, date)

The date is the date you want to extract the year from.

How do I add or subtract time from a date?

You can use the DATEADD function to add or subtract time from a date. The syntax of the function is as follows:

DATEADD(datepart, number, date)

The datepart is the part of the date you want to add or subtract from, the number is the amount of time you want to add or subtract, and the date is the date you want to add or subtract from.

What is the difference between the CONVERT and FORMAT functions?

The CONVERT function is used to convert a data type into another data type. It is commonly used to convert dates into different formats. The FORMAT function is used to format a value into a specific format. It is commonly used to format dates into different formats.