Question

I have a problem with a SQL query that I don’tr understand:
I am using WebMatrix with razor syntax.
I want to query my stock table and find how many of my top movers are in stock, as a percentage.

In the code bolock, i have:

var topmovers = db.QueryValue("select COUNT(STOCKCODE) from dbo.STOCK_ITEMS where STOCK_CLASSIFICATION = 170") ?? 0;   

var instock = db.QueryValue("select COUNT(STOCKCODE) from dbo.STOCK_ITEMS where STOCK_CLASSIFICATION = 170 and TOTALSTOCK > 0") ?? 0;   

var ofpc = instock/topmovers;`

then in the body, i have

@ofpc.ToString("P2")

It returns either 0 or 100, depending on which way around I have the variables instock and topmovers. I want a percentage, not 100% or 0%!

If i go @instock.ToString(); i get 862

If I go @topmovers.ToString(); i get 965

According to my maths, 862/965 is 0.8932 (89.32%)

However, I am getting 0.00% as the result of ofpc when I output it with @ofpc.ToString("P2")

I’m obviously wrong somewhere…

Answer 1

The same problem happens in SQL Server, which does integer division, so:

select 1/2

Always returns 0.

So, you need to cast one of the values to a floating point number. Can you use this expression:

var ofpc = cast(instock as float)/topmovers;

Or something similar? Perhaps:

var ofpc = (instock*1.0)/topmovers

You can also make the database return a floating point value:

var topmovers = db.QueryValue("select cast(COUNT(STOCKCODE) as float) from dbo.STOCK_ITEMS where STOCK_CLASSIFICATION = 170") ?? 0;`

What I’ve done is convert the first count to a float inside SQL. You can undoubtedly do this at the application level, but I’m more familiar with SQL. This should make the topmovers variable a float, and the division will be a floating point division.