使用 CROSS APPLY 取消透视列，其中值包括 int 和 varchar

Question

我正在尝试取消透视表列，但遇到从 varchar 到 int 的转换错误。我的表中的所有列都是整数，除了一列，即 varchar。错误详情如下。

将 varchar 值“View Test”转换为数据类型 int 时转换失败。

DECLARE @tableData AS TABLE (
    TD_ID INT PRIMARY KEY IDENTITY(1,1)
    , View0 INT
    , View1 INT
    , View2 INT
    , Remarks Varchar(20)
)

INSERT INTO @tableData (View0, View1, View2, Remarks)
VALUES(1, 0, 1, 'View Test')

SELECT column_Name, column_value
FROM @tableData
CROSS APPLY (
    VALUES
    ('View0',View0)
    , ('View1',View1)
    , ('View2',View2)
    , ('Remarks',Remarks)
) Q (column_Name, column_value)

Answer 1

就像@Dale K所说，你可以先转换为varchar。这是示例代码：

DECLARE @tableData AS TABLE (
    TD_ID INT PRIMARY KEY IDENTITY(1,1),
    View0 INT,
    View1 INT,
    View2 INT,
    Remarks Varchar(20)
)

INSERT INTO @tableData (View0, View1, View2, Remarks)
VALUES (1, 0, 1, 'View Test')

SELECT column_Name, column_value
FROM (
    SELECT
        CAST(View0 AS VARCHAR(20)) AS View0,
        CAST(View1 AS VARCHAR(20)) AS View1,
        CAST(View2 AS VARCHAR(20)) AS View2,
        Remarks
    FROM @tableData
) src
UNPIVOT (
    column_value FOR column_Name IN (View0, View1, View2, Remarks)
) unpvt;

这是小提琴链接