Summary: in this tutorial, you will learn how to use the Db2
LOWER() function to transform all characters of a string to lowercase.
LOWER() function overview
LOWER() function accepts a string and returns a new string in which all characters in the original string are converted to lowercase.
The following shows the syntax of the
In this syntax, the
expression is a character string expression that evaluates to a string or a value which can be implicitly converted to a string.
Similar to the
UPPER() function, the
LOWER() function can be useful for case insensitive searches.
LOWER() function examples
Let’s take some examples of using the
1) Using Db2
LOWER() to convert a literal string to lowercase
The following example uses the
LOWER() function to convert the string
'Db2 lower' to uppercase:
SELECT LOWER('Db2 lower') result FROM sysibm.sysdummy1;
Here is the result set:
RESULT --------- db2 lower
2) Using Db2
LOWER() to perform case insensitive searches
See the following
publishers table in the sample database:
This example uses the
LOWER() function to find the publisher whose name is
SELECT publisher_id, name FROM publishers WHERE LOWER(name) = 'apress';
Here is the output:
PUBLISHER_ID NAME ------------ ------- 14 Apress
To improve the speed of the query, you can create an expression-based index on the name column of the
CREATE INDEX ix_uname ON publishers(UPPER(name));
In this tutorial, you have learned how to use the Db2
LOWER() function to convert all characters of a string to lowercase.