ATAN() Function in Oracle

In Oracle, the ATAN() function returns the arctangent (inverse tangent) of its argument.

In other words, it returns the value whose tangent is the argument.

Syntax

The syntax goes like this:

ATAN(n)

Where n can be in an unbounded range.

Example

Here’s an example:

SELECT ATAN(0.7)
FROM DUAL;

Result:

                                   ATAN(0.7) 
____________________________________________ 
   0.610725964389208616543758876490236093837

Non-Numeric Argument

The argument can be any numeric data type or any nonnumeric data type that can be implicitly converted to a numeric data type.

Here’s what happens when we provide a non-numeric argument that can’t be converted to a numeric data type:

SELECT ATAN('One')
FROM DUAL;

Result:

Error starting at line : 1 in command -
SELECT ATAN('One')
FROM DUAL
Error report -
ORA-01722: invalid number

Null Values

Passing null to ATAN() returns null:

SET NULL 'null';

SELECT ATAN(null)
FROM DUAL;

Result:

   ATAN(NULL) 
_____________ 
         null

By default, SQLcl and SQL*Plus return a blank space whenever null occurs as a result of a SQL SELECT statement.

However, you can use SET NULL to specify a different string to be returned. Here I specified that the string null should be returned.

Incorrect Argument Count

Calling ATAN() without passing any arguments returns an error:

SELECT ATAN()
FROM DUAL;

Result:

Error starting at line : 1 in command -
SELECT ATAN()
FROM DUAL
Error at Command Line : 1 Column : 8
Error report -
SQL Error: ORA-00909: invalid number of arguments
00909. 00000 -  "invalid number of arguments"
*Cause:    
*Action:

And passing the wrong number of arguments results in an error:

SELECT ATAN(1, 2)
FROM DUAL;

Result:

Error starting at line : 1 in command -
SELECT ATAN(1, 2)
FROM DUAL
Error at Command Line : 1 Column : 8
Error report -
SQL Error: ORA-00909: invalid number of arguments
00909. 00000 -  "invalid number of arguments"
*Cause:    
*Action: