在SQL中，如何将VARCHAR转换为字符串？

我正在尝试使用参数在SQL Server 2008 R2上执行大容量插入操作。但是，我遇到了这样的问题：函数需要一个字符串，而我要传递一个VARCHAR。我的SQL在下面

DECLARE @filepath VARCHAR(30)
DECLARE @current_symbol VARCHAR(30)

DECLARE symbol_cursor CURSOR FOR
SELECT symbol FROM stocks.dbo.description WHERE 1=1

OPEN symbol_cursor;

FETCH NEXT FROM symbol_cursor INTO @current_symbol

WHILE @current_symbol is not null
BEGIN
SET @filepath = 'C:\Users\stkerr\Desktop\stockPricing\' + @current_symbol + '.prices'
BULK
INSERT stocks.dbo.pricing
FROM @filepath
WITH
(
    FIRSTROW = 2,
    FIELDTERMINATOR=',',
    ROWTERMINATOR='\n',
    ORDER   ( [date], [open], high, low, [close],volume),
        ERRORFILE='C:\Users\stkerr\errors.txt'.
)

FETCH NEXT FROM symbol_cursor INTO @current_symbol
END 
GO

问题是在执行SET@filepath语句时出现的

---

有什么想法吗？

为了将变量（

@filepath

）中的文件指定为

批量插入

，您需要构造动态TSQL并执行它

e、 g

sql中没有“字符串”类型。如果您在使用

set

语句时遇到问题，很可能是因为您给了它最大长度30个字符，而您的文本比这个长度长

如果是@filepath中的

给您带来了麻烦，那是因为大容量插入不会在
From
语句中使用变量

总的来说，我认为您的选择可能是通过动态sql执行大容量插入。在变量中构建语句，然后执行它。
我同意Mitch Wheat的观点，动态SQL是一种可行的方法。我认为，你还有一些其他问题需要解决。您的文件路径需要用引号括起来，我认为在您的错误文件名之后可能会有一个零散的点。试着做一些类似的事情

DECLARE @filepath VARCHAR(30)
DECLARE @current_symbol VARCHAR(30)
DECLARE @sql VARCHAR(8000)

SET QUOTED_IDENTIFIER OFF

SET @current_symbol = (SELECT "tst") 

IF @current_symbol is not null
BEGIN
SET @filepath = "C:\Users\stkerr\Desktop\stockPricing\" + @current_symbol + ".prices"

SET @sql = "BULK INSERT stocks.dbo.pricing FROM '" + @filepath + "' WITH ( FIRSTROW = 2, FIELDTERMINATOR=',', ROWTERMINATOR='\n', ORDER   ( [date], [open], high, low, [close],volume), ERRORFILE='C:\Users\stkerr\Desktop\stockPricing\errors.txt') "
END 

PRINT @SQL -- Check out the result of this, and try and run it by itself.

EXEC (@SQL)

祝你好运。注意，我的示例不能像Mitch建议的那样使用动态SQL。首先让它工作，然后用Mitch的例子重新实现

DECLARE @filepath VARCHAR(30)
DECLARE @current_symbol VARCHAR(30)
DECLARE @sql VARCHAR(8000)

SET QUOTED_IDENTIFIER OFF

SET @current_symbol = (SELECT "tst") 

IF @current_symbol is not null
BEGIN
SET @filepath = "C:\Users\stkerr\Desktop\stockPricing\" + @current_symbol + ".prices"

SET @sql = "BULK INSERT stocks.dbo.pricing FROM '" + @filepath + "' WITH ( FIRSTROW = 2, FIELDTERMINATOR=',', ROWTERMINATOR='\n', ORDER   ( [date], [open], high, low, [close],volume), ERRORFILE='C:\Users\stkerr\Desktop\stockPricing\errors.txt') "
END 

PRINT @SQL -- Check out the result of this, and try and run it by itself.

EXEC (@SQL)