插入时违反主键约束

Question

我有一个表，其主键由 4 列组成，如下所示：

CREATE TABLE [dbo].[INV_STOCK_TEST]
(
    [STOCK_WRH_ID]  [varchar](6) NOT NULL,
    [STOCK_LOC_ID]  [varchar](6) NOT NULL,
    [STOCK_ITEM_NO] [varchar](20) NOT NULL,
    [STOCK_BEG_QTY] [decimal](9, 2) NULL,
    [YEAR]          [nvarchar](5) NOT NULL, 

    CONSTRAINT [PK__INV_STOC__3B64B7082B9540B9]
    PRIMARY KEY CLUSTERED  (
        [STOCK_WRH_ID] ASC,
        [STOCK_LOC_ID] ASC,
        [STOCK_ITEM_NO] ASC,
        [YEAR] ASC
    )WITH (
        PAD_INDEX = OFF,
        STATISTICS_NORECOMPUTE = OFF, 
        IGNORE_DUP_KEY = OFF,
        ALLOW_ROW_LOCKS = ON, 
        ALLOW_PAGE_LOCKS = ON
    ) ON [PRIMARY]
) ON [PRIMARY]

我有一个程序来更新这个表中的年度数据

DECLARE @YEAR nvarchar(20)

SET @YEAR = (SELECT TOP 1 [YEAR] FROM INV_STOCK_TEST ORDER BY [YEAR] DESC)

INSERT INTO INV_STOCK_TEST([STOCK_WRH_ID], [YEAR],
                           [STOCK_LOC_ID], [STOCK_BEG_QTY], [STOCK_ITEM_NO])
    SELECT
        STOCK_WRH_ID, @YEAR + 1,
        STOCK_LOC_ID, 0, STOCK_ITEM_NO
    FROM
        INV_STOCK_TEST

插入数据示例

A   A   ITEM_A  0.00    2014
A   A   ITEM_A  0.00    2015
B   B   ITEM_B  0.00    2014
B   B   ITEM_B  0.00    2015

2014 年到 2015 年没关系，但是当 2015 年到 2016 年运行程序时，我收到此错误：

违反主键约束“PK__INV_STOC__3B64B7082B9540B9”。 无法在对象“dbo.INV_STOCK_TEST”中插入重复键。这 重复键值为 (A, A, ITEM_A, 2017)。

我无法更改主键，如何解决这个问题？

Answer 1

拥有一个与记录相关的 ID 字段并将其用作主键，而不是尝试创建多个非唯一标识字段。

CREATE TABLE [dbo].[INV_STOCK_TEST]
(
[PK_ID]         [INT] PRIMARY KEY CLUSTERED,
[STOCK_WRH_ID]  [varchar](6) NOT NULL,
[STOCK_LOC_ID]  [varchar](6) NOT NULL,
[STOCK_ITEM_NO] [varchar](20) NOT NULL,
[STOCK_BEG_QTY] [int] NULL, -- decimals lack precision
                            -- use integers when dealing with discrete.
[YEAR]          [varchar](5) NOT NULL --I would use a datetime here
                                      --purely for formatting reasons
)

该过程应该完全相同。