SQL 服务器 : summing two variables

Question

我正在尝试添加两个变量

DECLARE @RentsSum MONEY
SET @RentsSum = (SELECT SUM(Price)
                 FROM Rents
                 WHERE StartDate IS NOT NULL)
GO

DECLARE @SalesSum MONEY
SET @PriceSum = (SELECT SUM(Price)
                 FROM Purchases
                 WHERE DateBought IS NOT NULL)
GO

DECLARE @SalesAndRentsSum MONEY

SET @SalesAndRentsSum = @RentsSum + @PriceSum;

SELECT @SalesAndRentsSum

变成了一个，但我在这里遇到了一些奇怪的错误...

Must declare the scalar variable "@PriceSum".

Must declare the scalar variable "@RentsSum".

Answer 1

删除所有 GO 单词。这里有三个单独的批处理，必须在该批处理的范围内声明变量。

DECLARE @RentsSum MONEY, @SalesSum MONEY, @SalesAndRentsSum MONEY

SET @RentsSum = (SELECT SUM(Price)
                FROM Rents
                WHERE StartDate IS NOT NULL)

SET @SalesSum = (SELECT SUM(Price)
                FROM Purchases
                WHERE DateBought IS NOT NULL)

SET @SalesAndRentsSum = @SalesSum + @PriceSum

SELECT @SalesAndRentsSum