SQL Server PDURATION Function

Updated 2024-02-28 20:29:28.027000

Description

Use the scalar function PDURATION to calculate the number of periods required by an investment to reach a specified value. The formula is:

PDURATION=\frac{\ln{fv}-\ln{pv}}{\ln{\left(rate+1\right)}

Where

column 1	column 2	column 3
fv	=	the future value of the investment
pv	=	the present value of the investment
rate	=	the periodic interest rate.

Syntax

   SELECT [westclintech].[wct].[PDURATION] (
      <@Rate, float,>
     ,<@PV, float,>
     ,<@FV, float,>)

Arguments

@Rate

Periodic interest rate. @Rate must be of type float or of a type that implicitly converts to float.

@PV

Present value of the investment. @PV must be of type float or of a type that implicitly converts to float.

@FV

Future value of the investment. @FV must of a type float or of a type that implicitly converts to float.

Return Type

float

Remarks

If @PV is NULL then @PV = 0.

If @PV = 0 then NULL is returned.

If @FV is NULL then @FV = 0.

If @FV = 0 then NULL is returned.

If @Rate is NULL then @Rate = 0.

If @Rate = 0 then NULL is returned.

If @Rate < -1 then NULL is returned.

Examples

SELECT wct.PDURATION(   wct.PERIODRATE(.08, 1, 12) / 12, --@Rate
                        1000,                            --@PV
                        1259.712                         --@FV
                    ) as PDURATION;

This produces the following result.

PDURATION
36.0000000000002