将列名声明为变量

Question

我在下面的查询中遇到了一个问题。

DECLARE @CC VARCHAR(100)
SET @CC = 'MKT_COV_CAR_LFR'
DECLARE @SQL VARCHAR(16384)
SET @SQL =      
'INSERT INTO PP_Industry
SELECT
    R.Year,
    ''01'' AS Carline,
    Sales_Locality,
    '+@CC+' AS Reg, 
    National_Reg,
    CAST('+@CC+' AS FLOAT) / CAST(National_Reg AS FLOAT) AS Reg_Share
FROM
    PP_Registrations AS R
    JOIN
        (
            SELECT
                Year,
                SUM('+@CC+') AS National_Reg
            FROM
                PP_Registrations
            GROUP BY
                Year
        ) AS SQ ON R.Year = SQ.Year'

EXEC @SQL

运行它时会收到以下错误。请帮帮我！

错误(2812)存储过程‘插入到PP_Industry中选择R.Year，'01’作为Carline，Sales_Locality，MKT_COV_CAR_LFR作为Reg，Nationa‘没有找到。指定owner.objectname或使用sp_help检查对象是否存在(sp_help可能产生大量输出)。

Answer 1

如果您运行自定义SQL语句，您应该像这样执行它：

exec (@SQL)