PostgreSQL – UPPER function
In PostgreSQL, the UPPER function is used to convert a string into upper case.
Syntax: UPPER(string_expression)
Like the LOWER function, the UPPER function accepts a string expression or string-convertible expression and converts it to an upper case format. In case the argument is not a string, the user must use the CAST function to explicitly convert it.
Example 1:
The following statement uses the CONCAT function and UPPER function to return the full name of staff in the upper case from the staff table of the
SELECT CONCAT ( UPPER (first_name), UPPER (last_name) ) as full_name FROM staff;
Output:
Example 2:
The following statement converts a lower case string to an upper case format:
SELECT UPPER('w3wiki');
Output: