The SQLite UPPER function is used to convert all the characters in a given string to uppercase. This function is useful when you want to perform case-insensitive comparisons in your SQL queries or when you want to standardize the format of your data.


The syntax for using the UPPER function in SQLite is:


Here, string is the string that you want to convert to uppercase.


For example, let’s say you have a table called employees with columns first_name and last_name, and you want to retrieve all the employees whose last name is “SMITH”, regardless of whether it is in uppercase or lowercase. You can use the UPPER function to convert the last_name column to uppercase and then compare it to the uppercase version of the string “SMITH” as follows:

FROM employees 
WHERE UPPER(last_name) = UPPER('SMITH');

This query will retrieve all the rows in the employees table where the last_name column is “SMITH”, “smith”, “Smith”, or any other variation of uppercase and lowercase characters.

In addition to the UPPER function, SQLite also provides a LOWER function that works in a similar way but converts all the characters in a given string to lowercase.