PostgreSQL Alphanumeric String isalnum
In PostgreSQL, you can use the isalnum function to determine if a string is alphanumeric or not. The isalnum function returns TRUE if all characters in the string are either alphabetic or numeric. It returns FALSE otherwise.
Here is an example of how to use the isalnum function in PostgreSQL:
SELECT isalnum(‘hello123’); — Returns TRUE
SELECT isalnum(‘Hello, world!’); — Returns FALSE
SELECT isalnum(‘12345’); — Returns TRUE
In the first example, the Alphanumeric String isalnum function returns TRUE. It does so because all characters in the string 'hello123' are either alphabetic or numeric.
In the second example, the isalnum function returns FALSE. This happens because the string 'Hello, world!' contains non-alphanumeric characters.
In the third example, the isalnum function returns TRUE. The string '12345' contains only numeric characters.
Real-life data examples of using the PostgreSQL Alphanumeric String isalnum function appear in many applications that handle user input or data validation. For example, a web application might use the isalnum function to validate the username field during registration. This ensures that it contains only alphanumeric characters.
Similarly, a data analytics application might use the isalnum function to validate input data before processing. This ensures the application uses only valid data in the analysis.
