Oracle has a lot of powerful functions.
SQL functions have a name, followed by one or more arguments (between parentheses) in a comma-separated list.
You can use functions in expressions, in the same way that you can use operators.
These are the six SQL function categories, based on their operand types:
T?he following table lists some examples of SQL functions.
| Function | Explanation |
|---|---|
| AVG(MSAL) | The average monthly salary |
| SQRT(16) | The square root of 16 |
| LENGTH(INIT) | The number of characters in the INIT column value |
| LOWER(ENAME) | ENAME column value, in lowercase |
| SUBSTR(ENDDATE,4,3) | Three characters of the ENDDATE column value, from the fourth position |
Oracle allows you to create your own SQL functions by using the PL/SQL or Java languages.