Using the SUBSTR() Oracle Function

Using SUBSTRING() in the SELECT clause

The SUBSTR() function is used to extract a character string from a given starting position for a given length. 

SELECT  
        SUBSTR(COURSE_DESIGNATER,6,3) as "Course number"                   
FROM    COURSES
WHERE   COURSE_DESIGNATER LIKE 'Excel%'     

Format a column using SUBSTR() and LOWER() and UPPER() functions

It is possible to use the Oracle LOWER() and UPPER() functions in conjunction with the SUBSTR() function to accomplish different types of formatting.

SELECT 
  UPPER(SUBSTR(lastname,1,1)) || LOWER(SUBSTR(lastname,2,29)) AS "Lastname"
FROM Students