How to write a SQL Query to reverse every word present in a string with an example?. SQL reverse string is one of the standard Interview Questions you might face in the interviews.
SQL Reverse String Word by Word Example
The SUBSTRING function allows you to extract and display the part of a string. In this SQL example, we show you how to Select the string before the space symbol and reverse those string words.
DECLARE @Source VARCHAR(MAX) DECLARE @Destination VARCHAR(MAX) DECLARE @Length INT SET @Source = 'Welcome to SQL Server Tutorial Service at Tutorial Gateway' SET @Destination = '' WHILE LEN(@Source) > 0 BEGIN IF CHARINDEX(' ', @Source) > 0 BEGIN SET @Destination = SUBSTRING(@Source, 0, CHARINDEX(' ', @Source)) + ' ' + @Destination SET @Source = LTRIM(RTRIM(SUBSTRING(@Source, CHARINDEX(' ', @Source) + 1, LEN(@Source)))) END ELSE BEGIN SET @Destination = @Source + ' ' + @Destination SET @Source = '' END END SELECT @Destination

First, we declared three variables using the DECLARE statement. Next, we used the WHILE Loop to iterate every character present in the @Source. For the condition inside the SQL Server while loop, we used the LEN Function to check whether the length of the source is greater than 0 or not.
Within the while loop of SQL reverse string example, we used the SUBSTRING Function to set the @Destination value. And it allows three parameters, and they are Source, start point, endpoint. Here we assigned the
- Source as @Source or you can use Column Name
- Next, we used the starting position as 0.
- Next, we used the CHARINDEX Function to find the ‘ ‘ So that the endpoint will be before the space.
- Lastly, we are adding this to @Destination, and it is empty at the starting of the loop
To set the @Source value (it means to update the @source variable), we are using the SUBSTRING Function. Here we assigned the
- Source as @Source or you can use Column Name
- Next, we used the CHARINDEX Function to find the empty space, and then we added 1. so that the starting point will be after space.
- Lastly, we used the LEN Function to specify the end value
From the above SQL reverse string analysis, you can observe that,
- SET @Destination means we are extracting the word starting at 0 indexes and up to empty space. That will be the first word.
- Once we got our first word, we will remove that word from @Source using the SET @Source code.
SQL Reverse String Word by Word Example 2
Although the above example will return the result, we want to wrap the reverse string in the User Defined Function. I suggest you refer to the User Defined article for better understanding.
CREATE FUNCTION [ReverseStringWords] ( @Source VARCHAR(MAX) ) RETURNS VARCHAR(MAX) BEGIN DECLARE @Destination VARCHAR(MAX) SET @Destination = '' DECLARE @Length INT WHILE LEN(@Source) > 0 BEGIN IF CHARINDEX(' ', @Source) > 0 BEGIN SET @Destination = SUBSTRING(@Source, 0, CHARINDEX(' ', @Source)) + ' ' + @Destination SET @Source = LTRIM(RTRIM(SUBSTRING(@Source, CHARINDEX(' ', @Source) + 1, LEN(@Source)))) END ELSE BEGIN SET @Destination = @Source + ' ' + @Destination SET @Source = '' END END RETURN @Destination END
We can find the user defined function in two ways. Please navigate to the Database that contains the function -> Programmability -> Scalar-valued Functions -> functionName. Next, right click on the function name will open the context menu. Here, please choose the Script Function as -> Select To -> New Query Editor Window option.

Or write the following code snippet to reverse string in SQL Server
-- String Reverse Example SELECT [dbo].[ReverseStringWords]('Welcome To SQL Server Tutorial Service at Tutorial Gateway') GO
