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Editorial Team
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Asked: 2026-06-13T11:07:07+00:00

In a SQL view, what is the best way to handle the problem of

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In a SQL view, what is the best way to handle the problem of reusing previous calculations such that they do not become complex/unreadable.

In a stored proc, we could store/output @variables and do the calcs using them as we went along, but my problem is that this must be done in a view.

What’s the best way to go about this? (bearing in mind there are a few thousand rows of data).

SELECT  
        /* CALC 1 output to view row */
        (SELECT Act.ValueInContractCurrency/dbo.[Contract].Value * 
            (SELECT ISNULL(SUM(dbo.Invoice.ValueInContractCurrency),0)
             FROM dbo.Invoice 
             WHERE dbo.Invoice.StageId = Act.StageId)) AS InvoicedValueInContractCurrency, 

        /* CALC 2 wraps CALC1 inside it and outputs to view row */
        (SELECT Act.ValueInContractCurrency - 
            (SELECT Act.ValueInContractCurrency/dbo.[Contract].Value * 
                (SELECT ISNULL(SUM(dbo.Invoice.ValueInContractCurrency),0)
                 FROM dbo.Invoice 
                 WHERE dbo.Invoice.StageId = Act.StageId))) AS RemainingValueInContractCurrency,        

        /* CALC 3 wraps CALC2 inside it (which in turn wraps CALC1) and outputs to view row */
        (SELECT ConCurrency.CurrentExchangeRate / dbo.[Contract].CostedExchangeRate *
            (SELECT Act.ValueInContractCurrency - 
                (SELECT Act.ValueInContractCurrency/dbo.[Contract].Value * 
                    (SELECT ISNULL(SUM(dbo.Invoice.ValueInContractCurrency),0)
                     FROM dbo.Invoice 
                     WHERE dbo.Invoice.StageId = Act.StageId)))) AS RemainingValueInFacilityCurrency

        /* etc... for 10 more calcs that get increasingly long and unreadable via wrapping */

        FROM dbo.Activity AS Act
        JOIN dbo.Stage ON Act.StageId = dbo.Stage.Id       
        JOIN dbo.[Contract] ON dbo.Stage.ContractId = dbo.[Contract].Id
        JOIN dbo.Facility  ON dbo.[Contract].FacilityId = Facility.Id
        JOIN dbo.Currency AS FacCurrency ON dbo.Facility.CurrencyId = FacCurrency.Id
        JOIN dbo.Currency AS ConCurrency ON dbo.[Contract].CurrencyId = ConCurrency.Id
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1 Answer

  1. Editorial Team

    Personally, I’d just subquery them. Although to be honest, SQL Server sees through the “wraps” and does reuse the expressions; you can verify that by checking the execution plan. 

            /* etc... for 10 more calcs that get increasingly long and unreadable via wrapping */

SELECT  *,
        /* CALC 3 wraps CALC2 inside it (which in turn wraps CALC1) and outputs to view row */
        (SELECT CurrentExchangeRate / CostedExchangeRate *
            RemainingValueInContractCurrency) AS RemainingValueInFacilityCurrency
FROM (
SELECT  *,
        /* CALC 2 wraps CALC1 inside it and outputs to view row */
        (SELECT ValueInContractCurrency - 
            InvoicedValueInContractCurrency) AS RemainingValueInContractCurrency
FROM (
SELECT  *,  
        /* CALC 1 output to view row */
        (SELECT Act.ValueInContractCurrency/dbo.[Contract].Value * 
            (SELECT ISNULL(SUM(dbo.Invoice.ValueInContractCurrency),0)
             FROM dbo.Invoice 
             WHERE dbo.Invoice.StageId = Act.StageId)) AS InvoicedValueInContractCurrency
        FROM dbo.Activity AS Act
        JOIN dbo.Stage ON Act.StageId = dbo.Stage.Id       
        JOIN dbo.[Contract] ON dbo.Stage.ContractId = dbo.[Contract].Id
        JOIN dbo.Facility  ON dbo.[Contract].FacilityId = Facility.Id
        JOIN dbo.Currency AS FacCurrency ON dbo.Facility.CurrencyId = FacCurrency.Id
        JOIN dbo.Currency AS ConCurrency ON dbo.[Contract].CurrencyId = ConCurrency.Id
        ) A
        ) B
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