Find Non Printable Ascii Characters In Sql

Understanding Non-Printable ASCII Characters

When working with SQL databases, it's not uncommon to encounter non-printable ASCII characters. These characters, also known as control characters, are used to control the flow of data or perform specific actions, but they can cause issues when trying to display or manipulate data. In this article, we'll explore how to find non-printable ASCII characters in SQL and discuss techniques for handling them.

Non-printable ASCII characters can be problematic because they can be invisible, making it difficult to detect them. However, there are ways to identify these characters using SQL queries. One approach is to use the ASCII function to get the ASCII value of each character in a string, and then filter out the values that correspond to non-printable characters.

Detecting and Handling Non-Printable Characters in SQL

Non-printable ASCII characters have values between 0 and 31, as well as 127. These characters include tabs, line breaks, and other control characters. To detect these characters, you can use a SQL query that selects the ASCII value of each character in a string and checks if it falls within the range of non-printable characters. For example, you can use the following query: SELECT * FROM table WHERE ASCII(char) < 32 OR ASCII(char) = 127;

Once you've identified non-printable ASCII characters in your SQL database, you'll need to decide how to handle them. One approach is to replace them with a printable character, such as a space or a null character. You can use the REPLACE function in SQL to achieve this. Alternatively, you can use the TRIM function to remove non-printable characters from the beginning and end of a string. By using these techniques, you can ensure that your data is clean and free of non-printable ASCII characters.