Revealing Hidden Characters in Oracle: A Guide to Non-Printable Characters
What are Non-Printable Characters?
When working with databases, it's essential to be aware of all the characters that are stored, including those that are not visible to the naked eye. Non-printable characters, also known as control characters, can be problematic if not handled properly. In Oracle, these characters can be particularly troublesome, but fortunately, there are ways to reveal them.
Non-printable characters are used for various purposes, such as formatting and control. They can be introduced into your database through user input, data imports, or even through SQL scripts. If left unchecked, these characters can cause issues with data processing, reporting, and even data integrity. It's crucial to identify and manage these characters to ensure the health and reliability of your database.
How to Identify Non-Printable Characters in Oracle
What are Non-Printable Characters? Non-printable characters are ASCII characters that are not visible on the screen. They include characters such as tabs, line feeds, and carriage returns. In Oracle, these characters can be represented using the CHR function, which returns the character represented by the specified ASCII code. For example, the ASCII code for a tab character is 9, so the expression CHR(9) would return a tab character.
How to Identify Non-Printable Characters in Oracle To identify non-printable characters in Oracle, you can use the DUMP function, which returns a string that represents the data type and the internal representation of the input value. By using the DUMP function, you can see the ASCII code for each character in your data, making it easier to spot non-printable characters. Additionally, you can use SQL scripts to search for specific non-printable characters and replace them with printable equivalents, ensuring your data is clean and reliable.