How to output the results of a stored procedure with a while loop MS SQL Server?

Question

I'm performing some calculations on tsunami's wave time between different radii. I'm having trouble outputting the results of the stored procedure into a table. The output I get is a blank table without any data stored. The log says "0 rows affected". For some reason my inputs and outputs are not registering. I thinking it could have something to do with the way I'm using the loop inside to SP.

    CREATE PROCEDURE SP_Tsunami
(
    @oceanDepth int,
    @radii1 int,
    @radii2 int,
    @tsunamiSpeed int OUTPUT,
    @tsunamiTimeDifference int OUTPUT
)
    AS
    BEGIN
        SET @tsunamiSpeed = sqrt(32.1725 * @oceanDepth) * (60.0/88.0);
        Truncate Table dbo.Tsunami

        DECLARE @i int
            SET @i = 0;
            WHILE (@i <= 10000)
            BEGIN
                INSERT INTO dbo.Tsunami (Radius, Wavetime)
                VALUES
                    (@i, (@i / @tsunamiSpeed))
                SET @i = @i + 100;  
            END         

        DECLARE @tsunamiTime1 int
        DECLARE @tsunamiTime2 int
        SET @tsunamiTime1 = (Select Wavetime From Tsunami WHERE Radius = @radii1);
        SET @tsunamiTime2 = (Select Wavetime From Tsunami WHERE Radius = @radii2);
        SET @tsunamiTimeDifference = (@tsunamiTime2 - @tsunamiTime1);   
    END

    /* Outputs */
    DECLARE @Out_tsunamiSpeed int
    DECLARE @Out_tsunamiTimeDifference int


    /* Inputs */
    DECLARE @IN_oceanDepth int
    DECLARE @IN_radii1 int
    DECLARE @IN_radii2 int
    SET @IN_oceanDepth = 15088; 
    SET @IN_radii1 = 2500; 
    SET @IN_radii2 = 7500;

    Execute SP_Tsunami @oceanDepth = @IN_oceanDepth, @radii1 = @IN_radii1, @radii2 = @IN_radii2, @tsunamiSpeed = @Out_tsunamiSpeed OUTPUT, @tsunamiTimeDifference = @Out_tsunamiTimeDifference OUTPUT

Answer 1

Doesn't make much sense to insert the data into table and then read it from there. All the rows you are inserting into your table eventually only one row is being read from the table to assign values to variables.

Also change the procedure name prefix from sp_ to something else, sp_ is system stored procedure prefix.

I have changed the procedure definition a little bit hope it makes sense.

ALTER PROCEDURE SP_Tsunami
(
    @oceanDepth int,
    @radii1 int,
    @radii2 int,
    @tsunamiSpeed int OUTPUT,
    @tsunamiTimeDifference int OUTPUT
)
AS
BEGIN
    SET @tsunamiSpeed = sqrt(32.1725 * @oceanDepth) * (60.0/88.0);


    DECLARE @tsunamiTime1 int
    DECLARE @tsunamiTime2 int

    SET @tsunamiTime1 = @radii1 / @tsunamiSpeed;
    SET @tsunamiTime2 = @radii2 / @tsunamiSpeed;

    SET @tsunamiTimeDifference = (@tsunamiTime2 - @tsunamiTime1);   
END
GO

Execute the procedure with your provided data.

/* Outputs */
DECLARE @Out_tsunamiSpeed int
DECLARE @Out_tsunamiTimeDifference int


/* Inputs */
DECLARE @IN_oceanDepth int
DECLARE @IN_radii1 int
DECLARE @IN_radii2 int
SET @IN_oceanDepth = 15088; 
SET @IN_radii1 = 2500; 
SET @IN_radii2 = 7500;

Execute SP_Tsunami @oceanDepth = @IN_oceanDepth
                 , @radii1 = @IN_radii1
                 , @radii2 = @IN_radii2
                 , @tsunamiSpeed = @Out_tsunamiSpeed OUTPUT
                 , @tsunamiTimeDifference = @Out_tsunamiTimeDifference OUTPUT

SELECT @Out_tsunamiSpeed AS Out_tsunamiSpeed
      ,@Out_tsunamiTimeDifference AS Out_tsunamiTimeDifference

Result Set:

Out_tsunamiSpeed    Out_tsunamiTimeDifference
     475                         10