Demystifying SQL Server Format Function for Devs

Hello, Dev! Are you tired of the never-ending struggle of formatting date and time values in SQL Server? Do you find yourself constantly googling formatting codes and syntax? Then you have come to the right place! In this article, we will dive deep into the SQL Server Format function and explore its myriad of capabilities. From custom date and time formats to handling null values, we’ve got you covered. So, sit back, relax, and let’s get started!

What is the SQL Server Format Function?

The SQL Server Format function is a built-in function that converts a date, time, or datetime2 value to a string using the specified format. It allows developers to format the output of date and time values in a way that suits their needs. The Format function was first introduced in SQL Server 2012 and is available in later versions as well. Let’s take a look at the syntax of the Format function:

Parameter
Description
value
The date, time, or datetime2 value to be formatted.
format
The format string to be applied to the value.

Custom Date and Time Formats

The Format function supports a wide range of custom date and time formats that can be used to format the output in any desired way. Let’s take a look at some of the commonly used format codes:

Date Formats

The following table showcases some of the commonly used date format codes:

Format Code
Description
Example
yyyy
Four-digit year
2022
yy
Two-digit year
22
MMMM
Full month name
January
MMM
Abbreviated month name
Jan
MM
Two-digit month
01
M
Single-digit month
1
dddd
Full weekday name
Monday
ddd
Abbreviated weekday name
Mon
dd
Two-digit day
01
d
Single-digit day
1

Time Formats

The following table showcases some of the commonly used time format codes:

Format Code
Description
Example
HH
Two-digit hour (24-hour clock)
14
H
Single-digit hour (24-hour clock)
14
hh
Two-digit hour (12-hour clock)
02
h
Single-digit hour (12-hour clock)
2
mm
Two-digit minute
05
m
Single-digit minute
5
ss
Two-digit second
30
s
Single-digit second
30
tt
AM/PM indicator
PM

Combining Formats

The Format function allows developers to combine date and time formats to create custom formats that meet their specific needs. For example, if you want to display the date and time in the format of “MM/dd/yyyy hh:mm:ss tt”, you can use the following format code:

SELECT FORMAT(GETDATE(), 'MM/dd/yyyy hh:mm:ss tt')

The above query will output the current date and time in the desired format.

Handling Null Values

The Format function also provides the option to handle null values using the ISNULL() function. The ISNULL() function checks whether the input value is null and returns a specified replacement value if it is. Let’s take a look at an example:

SELECT FORMAT(ISNULL(NULL, '01/01/2000'), 'MM/dd/yyyy')

The above query will output “01/01/2000” since the input value is null and the ISNULL() function replaces it with the specified value.

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FAQ

What versions of SQL Server support the Format function?

The Format function was first introduced in SQL Server 2012 and is available in later versions as well.

Can I use the Format function to format datetimeoffset values?

Yes, the Format function supports datetimeoffset values as well as date, time, and datetime2 values.

Can I use the Format function to format strings?

No, the Format function is specifically designed to format date, time, and datetime2 values. If you need to format strings, you can use the CONVERT() function instead.

Are custom date and time formats case-sensitive?

No, the custom format codes are not case-sensitive. Both “MM” and “mm” will produce the same output.

Can I use the Format function to format multiple date and time values simultaneously?

Yes, you can use the Format function to format multiple date and time values using the CONCAT() function. Concatenating the formatted values will result in a single string output.

Can I use the Format function to display the day of the week as a number?

Yes, you can use the format code “d” to display the day of the week as a number (1-7).

The Wrap-Up

The SQL Server Format function is a versatile tool that can handle a wide range of formatting requirements. From custom date and time formats to handling null values, the Format function provides developers with a simple yet powerful way to manipulate date and time values. We hope that this article has helped you to demystify the Format function and unlock its full potential. Happy coding, Dev!