UPPER is a case manipulation function that converts that converts text into uppercase. Text in this case is usually a column name or expression.
Here’s the syntax for Oracle UPPER function:
UPPER ( column-name | expression );
UPPER functions works with string data types. Once we input a column-name or expression it returns characters of string which are all in uppercase.
Oracle UPPER function Examples
1. Converting simple text to uppercase
Here’s the query:
SELECT UPPER ( 'qurosity' ) FROM dual;
Result:
The query simple returns the text in uppercase characters.
2. Converting entire column into uppercase using UPPER function
Here, we use the Employee table for this:
Here’s the query:
SELECT UPPER(first_name), last_name FROM employees;
Result:
The query returns all the text values in first_name column in uppercase while the last_name column remains unchanged.
In this tutorial, we learned how to use UPPER function to convert text characters to uppercase.