Summary: in this tutorial, you will learn how to use the Db2 UPPER()
function to convert all characters of a string to uppercase.
DB2 UPPER()
function overview
The UPPER()
function accepts a string and returns a new string in which all characters in the original string are converted to uppercase.
Here is the syntax of the UPPER()
function
UPPER(expression)
In this syntax, the expression
must evaluate to a character string or a value that can be implicitly converted to a character string.
The UPPER()
function is useful for case-insensitive searches.
Db2 UPPER()
function examples
Let’s take some examples of using the UPPER()
function.
1) Using Db2 UPPER()
to convert a literal string to uppercase.
This example uses the UPPER()
function to convert the string 'Db2 upper'
to uppercase:
SELECT
UPPER('Db2 upper') result
FROM
sysibm.sysdummy1;
Here is the result set:
RESULT
---------
DB2 UPPER
2) Using Db2 UPPER()
to perform case insensitive searches
See the following authors
table from the sample database:

The following example uses the UPPER()
function to search for authors whose last name are Anderson
:
SELECT
author_id,
first_name,
last_name
FROM
authors
WHERE
UPPER(last_name) = 'ANDERSON';
Here is the output:

To speed up this query, you should consider creating an expression-based index for the last_name
column:
CREATE INDEX ix_ulastname
ON authors(UPPER(last_name));
In this tutorial, you have learned how to use the Db2 UPPER()
function to convert all characters of a string to uppercase.