Introduction to the UPPER Function in GBase 8s

GBase databases offer a variety of string manipulation functions. This article provides a detailed introduction to the UPPER function in GBase 8s, including its functionality, syntax, important considerations, and practical examples.

Overview of the UPPER Function

The UPPER function accepts a string expression as a parameter and returns a string where every lowercase letter in the expression is replaced by its corresponding uppercase letter.

The following example uses the UPPER function to perform a case-insensitive search on the lname column for all employees with the last name "Curran":

SELECT title, INITCAP(fname), INITCAP(lname) 
FROM employees 
WHERE UPPER(lname) = 'CURRAN';

Since the INITCAP function is specified in the projection list, the database server returns the results in mixed case format.

For example, the output for a matching row could be: accountant James Curran.

Function Syntax

Where char is the input parameter to the function. This can be a column name, a string literal, or another expression. The result of the function will be a new string with all lowercase letters converted to uppercase. It's important to note that the UPPER function does not modify non-alphabetic characters, such as numbers, punctuation, or spaces.

Considerations

• If the string already contains uppercase letters, the UPPER function will only convert lowercase letters.
• Non-alphabetic characters remain unchanged.
• If the input string is NULL, the function will return NULL.
• The function name UPPER is not case-sensitive.
• The UPPER function can be nested with other functions to enable more complex string manipulations.

Examples

To better understand the usage of the UPPER function, here are a few practical query examples:

• Converting a lowercase string to uppercase:

SELECT UPPER('abc') FROM dual;

• If the string contains numbers, the numbers remain unchanged:

SELECT UPPER('abc123') FROM dual;

• If the string is NULL, the result will also be NULL:

SELECT UPPER(NULL) FROM dual;

• Real-world example: performing a case-insensitive query based on the last name:

SELECT title, INITCAP(fname), INITCAP(lname) 
FROM employees 
WHERE UPPER(lname) = 'CURRAN';

The query results might look like this:

Conclusion

The UPPER function is a powerful and practical string manipulation tool in GBase 8s. It allows you to quickly convert lowercase letters to uppercase, simplifying case-insensitive search operations. Thank you for reading!