Find Non Printable Characters In Sql Server

Understanding Non Printable Characters

When working with SQL Server, you may encounter non-printable characters that can cause issues with your data. These characters are not visible when you print or display the data, but they can still affect the way your database functions. Non-printable characters can be introduced into your database through various means, such as user input, data imports, or even through SQL scripts. It's essential to identify and handle these characters to ensure data integrity and prevent potential errors.

Non-printable characters can be challenging to detect, especially if you're not familiar with the ASCII character set. However, SQL Server provides several functions and techniques that can help you identify these characters. One way to detect non-printable characters is to use the ASCII function, which returns the ASCII code of a character. You can use this function to check for characters with ASCII codes that fall outside the printable range.

Detecting and Removing Non Printable Characters

To effectively detect and remove non-printable characters, you need to understand what they are and how they can affect your data. Non-printable characters include control characters, such as tabs, line breaks, and carriage returns, as well as other special characters that are not visible when printed. These characters can cause issues with data sorting, filtering, and aggregation, and can even lead to errors when trying to export or import data.

Once you understand what non-printable characters are, you can use various techniques to detect and remove them from your database. One approach is to use the REPLACE function to replace non-printable characters with a visible character, such as a space or a null character. You can also use the PATINDEX function to search for patterns that match non-printable characters. Additionally, you can use SQL Server's built-in data cleansing tools, such as the DATA_CLEANSE function, to automatically detect and remove non-printable characters from your data.