Question

我通过where子句和数量和角色（更新或减少数量）。

我的存储过程是：

ALTER PROCEDURE [dbo].[spUpdateQuantity]
(
    @WhereClause AS NVARCHAR,
    @Qty AS INT,
    @Role AS INT
)
AS
BEGIN
    DECLARE @CurrentQty AS INT;

    SELECT @CurrentQty = Quantity 
    FROM ProductMaster 
    WHERE SKUCode = @WhereClause;

    IF(@Role = 1)
    BEGIN
        UPDATE  ProductMaster
        SET     Quantity = (@CurrentQty + @Qty)
        WHERE   SKUCode = @WhereClause;
    END

    IF(@Role = 2)
    BEGIN
        UPDATE  ProductMaster
        SET     Quantity = (@CurrentQty - @Qty)
        WHERE   SKUCode = @WhereClause;
    END
END

目前的状态是

=====================================================
| ProductId   |  SKUCode     | Quantity  | 
------------------------------------------
| GA10000005  |  GA.42205    |  5        |

使用查询命令我更新状态，如...

DECLARE @return_value int

EXEC    @return_value = [dbo].[spUpdateQuantity]
        @WhereClause = N'GA.42205',
        @Qty = 3,
        @Role = 1

SELECT  'Return Value' = @return_value
GO

我的结果为0 ，状态与之前相同

有没有人有想法以这种方式更新库存数量？

Answer 1

如果要获取某个值而不是使用返回值，那么您应该将OUTPUT变量添加到存储过程，这是为了返回执行proc的状态：

ALTER PROCEDURE [dbo].[spUpdateQuantity]
(
    @WhereClause AS NVARCHAR(100),
    @Qty AS INT,
    @Role AS INT,
    @NewQty INT OUTPUT
)
AS
BEGIN
    DECLARE @CurrentQty AS INT;
    SELECT @CurrentQty = Quantity FROM ProductMaster WHERE SKUCode = @WhereClause;

    IF(@Role = 1)
    BEGIN
        SET @NewQty = @CurrentQty + @Qty

        UPDATE  ProductMaster
        SET     Quantity = @NewQty
        WHERE   SKUCode = @WhereClause;
    END
    IF(@Role = 2)
    BEGIN
        SET @NewQty = @CurrentQty - @Qty

        UPDATE  ProductMaster
        SET     Quantity = @NewQty
        WHERE   SKUCode = @WhereClause;
    END
END

并使用它：

DECLARE @return_value int, @NewQty INT

EXEC    @return_value = [dbo].[spUpdateQuantity]
        @WhereClause = N'GA.42205',
        @Qty = 3,
        @Role = 1,
        @NewQty = @NewQty OUTPUT

SELECT  @NewQty AS 'Return Value'

结果是0。问题的第二部分是显而易见的：将类型更改为@WhereClause AS NVARCHAR(100)。其他方式，它被视为@WhereClause AS NVARCHAR(1)，您传递的值被截断为N'G'。

https://msdn.microsoft.com/en-us/library/ms186939.aspx

nvarchar [（n | max）] 在数据定义或变量声明中未指定n时声明，默认长度为1.使用时未指定n CAST和CONVERT函数，默认长度为30。

Answer 2

这应该有效：

ALTER PROCEDURE [dbo].[spUpdateQuantity]
(
    @WhereClause AS NVARCHAR,
    @Qty AS INT,
    @Role AS INT
)
AS
BEGIN

        UPDATE  ProductMaster
        SET     Quantity = Quantity + case when @Role = 1 then @Qty else (@Qty*-1) end
        WHERE   SKUCode = @WhereClause;
END

Answer 3

你能完全删除@role并以正数或负数调用它吗？

ALTER PROCEDURE [dbo].[spUpdateQuantity]
(
    @SKUCode AS NVARCHAR,
    @Qty AS INT
)
AS
BEGIN   
        UPDATE  ProductMaster
        SET     Quantity = Quantity + @Qty
        WHERE   SKUCode = @SKUCode;
END

还将@WhereClause重命名为@SKUCode，因为它更容易理解它是什么。

使用存储过程获取和更新SQL中的数量

3 个答案: