SQL - EXP() Mathematical Function

SQL - EXP()

Exponential is a mathematical function which is almost always understood to mean the natural exponential function. The function EXP() returns the exponential value for the numeric expression. I have come across the EXP built in function in SQL Server and this function plays a very important role in data analytics calculations.

This function has one mandatory argument and it returns float type exponential value. In SQL, we have use the following syntax:

SQL Syntax: EXP(Argument) Argument: Any numeric expression. Return Type: float. Note: If value is numeric and not equal to zero then it will return float type otherwise it will return 1 for the 0 value. if argument is null then return type should be null.

The exponential function is equal to e^x. The value for the constant float number e is approximately 2.718281828 (natural logarithm).

----- declare local veriables declare @inpfloat float=1.2, @inpInt INT=1, @inpDecimal Decimal=1.2   ----- output parameters select EXP(@inpfloat) as 'Float EXP()', EXP(@inpINT) as 'Int EXP()', EXP(@inpDecimal) as 'Decimal EXP()'   Float EXP() Int EXP() Decimal EXP() 3.320116923 2.718281828 2.718281828 ---- set value 0 for veriable SET @inpfloat=0 SET @inpInt=0 SET @inpDecimal=0   ----- output parameters select EXP(@inpfloat) as 'Float EXP()', EXP(@inpINT) as 'Int EXP()', EXP(@inpDecimal) as 'Decimal EXP()' Float EXP() Int EXP() Decimal EXP() 1 1 1 We can view the difference on the above results. this is because 0 is to the power anything is equal to 1.

Conclusion

In simple words EXP() function is used to get the value of e ^ x because Exp expects a float and returns one, so the results from a decimal type include an implicit conversion to and from float and in turn this behaviour is due to inherent imprecision of FP numbers.