Should you choose the MONEY or DECIMAL(x,y) datatypes in SQL Server?

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时光取名叫无心
时光取名叫无心 2020-11-22 03:45

I\'m curious as to whether or not there is a real difference between the money datatype and something like decimal(19,4) (which is what money uses

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  •  悲哀的现实
    2020-11-22 03:48

    Never ever should you use money. It is not precise, and it is pure garbage; always use decimal/numeric.

    Run this to see what I mean:

    DECLARE
        @mon1 MONEY,
        @mon2 MONEY,
        @mon3 MONEY,
        @mon4 MONEY,
        @num1 DECIMAL(19,4),
        @num2 DECIMAL(19,4),
        @num3 DECIMAL(19,4),
        @num4 DECIMAL(19,4)
    
        SELECT
        @mon1 = 100, @mon2 = 339, @mon3 = 10000,
        @num1 = 100, @num2 = 339, @num3 = 10000
    
        SET @mon4 = @mon1/@mon2*@mon3
        SET @num4 = @num1/@num2*@num3
    
        SELECT @mon4 AS moneyresult,
        @num4 AS numericresult
    

    Output: 2949.0000 2949.8525

    To some of the people who said that you don't divide money by money:

    Here is one of my queries to calculate correlations, and changing that to money gives wrong results.

    select t1.index_id,t2.index_id,(avg(t1.monret*t2.monret)
        -(avg(t1.monret) * avg(t2.monret)))
                /((sqrt(avg(square(t1.monret)) - square(avg(t1.monret))))
                *(sqrt(avg(square(t2.monret)) - square(avg(t2.monret))))),
    current_timestamp,@MaxDate
                from Table1 t1  join Table1 t2  on t1.Date = traDate
                group by t1.index_id,t2.index_id
    

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