We can use Oracle Supplied functions in our queries. Alternatively, we can create our own functions and later use them in queries. We will learn about functions in the following chapters. In this section, we will explore a few commonly used functions. A complete list of Oracle Supplied functions is out of the scope of this book. You can refer to the Oracle documentation for more details.
Functions in Oracle can be of type scalar or aggregate. Scalar functions operate on a single row whereas the aggregate functions work on multiple rows. In this book we will cover the following Oracle Supplied functions:
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The UPPER function converts the character string to uppercase. Similarly, the LOWER function converts a given string to lowercase. The following is a sample query from an HR schema:
SQL> SELECT...