Hello Dev! If you are working with SQL Server, you may often find yourself needing to format dates in various ways. This can be a challenging task if you’re not familiar with the syntax and functions that SQL Server offers. In this article, we will cover the various ways in which you can format dates in SQL Server, including some helpful tips and frequently asked questions.
Understanding Date Formats
Before we dive into the specific functions and syntax for formatting dates in SQL Server, it’s important to have a basic understanding of date formats. A date in SQL Server is stored as a numerical value that represents the number of days since January 1, 1900. While this is not the most user-friendly format, it allows SQL Server to perform complex calculations and comparisons with ease.
To display a date in a more human-readable format, you will need to use formatting functions that convert the numerical value into a string. The specific format you choose will depend on your requirements and personal preferences.
Date Formats in SQL Server
SQL Server offers a variety of formatting options for dates, which can be overwhelming at first. Some of the most commonly used date formats in SQL Server include:
Format |
Output |
|---|---|
YYYY-MM-DD |
2022-06-15 |
MM/DD/YYYY |
06/15/2022 |
DD-MON-YYYY |
15-JUN-2022 |
MON DD, YYYY |
JUN 15, 2022 |
These are just a few examples of the many date formats that SQL Server supports. Don’t worry if you don’t see the format you need – we will cover how to create your own custom formats later in this article.
Using the Convert Function
One of the most common ways to format dates in SQL Server is by using the CONVERT function. This function allows you to convert a date from its internal numerical format into a string with the format of your choice. Here’s an example:
SELECT CONVERT(VARCHAR(10), GETDATE(), 101)
This query will return the current date in the format “MM/DD/YYYY”. Let’s break down what each part of this query does:
-
CONVERT(VARCHAR(10), ... ): This tells SQL Server to convert the date value into a string with a maximum length of 10 characters. -
GETDATE(): This function returns the current date and time. -
101: This is the style code that tells SQL Server to use the “MM/DD/YYYY” format.
Style Codes for Date Formats
The CONVERT function uses style codes to specify the output format of the date. Here are some of the most commonly used style codes for date formats in SQL Server:
Style Code |
Output Format |
|---|---|
101 |
MM/DD/YYYY |
102 |
YYYY.MM.DD |
103 |
DD/MM/YYYY |
104 |
DD.MM.YYYY |
You can find a full list of style codes in the SQL Server documentation.
Using the Cast Function
In addition to the CONVERT function, you can also use the CAST function to format dates in SQL Server. The CAST function is similar to CONVERT, but it requires the use of a specific data type. Here’s an example:
SELECT CAST(GETDATE() AS VARCHAR(10))
This query will return the current date as a string with a maximum length of 10 characters. The specific format will depend on your SQL Server settings.
Creating Custom Date Formats
If none of the built-in date formats in SQL Server meet your requirements, you can create your own custom format using the FORMAT function. The FORMAT function was introduced in SQL Server 2012 and allows you to specify a custom format string. Here’s an example:
SELECT FORMAT(GETDATE(), 'dddd, MMMM dd, yyyy')
This query will return the current date in the format “Wednesday, June 15, 2022”. Let’s break down what each part of this query does:
-
FORMAT(..., 'custom format string'): This tells SQL Server to format the date using the custom format string specified inside the single quotes. -
GETDATE(): This function returns the current date and time.
The custom format string can contain a combination of literal text and format specifiers. Here are some of the most commonly used format specifiers for dates in SQL Server:
Format Specifier |
Output |
|---|---|
yyyy |
Year (4 digits) |
yy |
Year (2 digits) |
MMMM |
Month (full name) |
MMM |
Month (short name) |
MM |
Month (2 digits) |
M |
Month (1 or 2 digits) |
dd |
Day (2 digits) |
d |
Day (1 or 2 digits) |
ddd |
Day of week (short name) |
dddd |
Day of week (full name) |
You can find a full list of format specifiers in the SQL Server documentation.
Frequently Asked Questions
How do I display only the date without the time?
To display only the date without the time, you can use the CONVERT or CAST function with a specific format code. Here’s an example:
SELECT CONVERT(VARCHAR(10), GETDATE(), 120)
This query will return the current date in the format “YYYY-MM-DD”. You can also use the CAST function with a specific data type to achieve the same result.
How do I add or subtract days from a date?
To add or subtract days from a date, you can use the DATEADD function. Here’s an example:
SELECT DATEADD(day, 7, '2022-06-15')
This query will add 7 days to the date ‘2022-06-15’, resulting in the date ‘2022-06-22’. You can also subtract days by using a negative number.
How do I convert a string to a date?
To convert a string to a date, you can use the CONVERT or CAST function with a specific format code. Here’s an example:
SELECT CONVERT(DATE, '2022-06-15', 120)
This query will convert the string ‘2022-06-15’ into a date value. The specific format code (120) tells SQL Server to expect the date in the “YYYY-MM-DD” format.
How do I display dates in a specific time zone?
SQL Server does not natively support time zones, but you can use the functions and syntax described in this article to convert dates to a specific time zone. Keep in mind that this may require some additional research or the use of third-party libraries.
How do I perform calculations with dates?
SQL Server supports a variety of functions for performing calculations with dates, such as DATEDIFF, DATEADD, and DATEPART. These functions allow you to determine the difference between two dates, add or subtract days, months, or years from a date, and extract specific parts of a date (such as the month or day).
How do I handle dates that are stored as text or in a non-standard format?
If your dates are stored as text or in a non-standard format, you will need to first convert them to a valid date format using the CONVERT or CAST function. Depending on the format of the original date, you may need to use a custom format code.
Conclusion
Formatting dates in SQL Server may seem like a daunting task at first, but with the right syntax and functions, it can be a breeze. Whether you need to display dates in a specific format, perform calculations with dates, or convert dates to and from strings, SQL Server has you covered. Remember to always consult the documentation and experiment with different functions and format codes to find what works best for your needs.