Sql server 如何在批量插入中使用一些变量为Lastrow和Firstrow参数赋值？

我在执行上述脚本时出错 任何人都可以解释在大容量插入语句中使用某个变量来指定Lastrow和firstrow参数的正确方法是什么？

类似这样的内容：

DECLARE @sqlCommand VARCHAR(MAX) DECLARE @NAME varchar (100)
DECLARE @FIRSTROW INT,@LASTROW INT
SET @FIRSTROW =
  (SELECT TOP 1 [Id]
   FROM [dbo].[TableB]
   ORDER BY [Id] DESC) + 1
SET @LASTROW = @FIRSTROW + 4
SELECT @NAME =
  (SELECT 'C:\InsertTestdata.txt')
SET NOCOUNT ON;


SET @sqlCommand = 'BULK INSERT [dbo].[TableA] FROM ''' + @NAME + '''
                            WITH (DATAFILETYPE = ''char'',
                            FIELDTERMINATOR = '','',
                            ROWTERMINATOR = '''+CHAR(10)+''',
                            FIRSTROW = 2,
                            LASTROW = '''+ @LASTROW +'''
                            );' 
EXEC (@sqlCommand);

输出

DECLARE @sqlCommand VARCHAR(MAX) DECLARE @NAME varchar (100)
DECLARE @FIRSTROW INT,@LASTROW INT
SET @FIRSTROW = 4
  --(SELECT TOP 1 [Id]
  -- FROM [dbo].[TableB]
  -- ORDER BY [Id] DESC) + 1
SET @LASTROW = @FIRSTROW + 4
SELECT @NAME =
  (SELECT 'C:\InsertTestdata.txt')
SET NOCOUNT ON;


SET @sqlCommand = concat('BULK INSERT [dbo].[TableA] FROM ''' , @NAME , '''
                            WITH (DATAFILETYPE = ''char'',
                            FIELDTERMINATOR = '','',
                            ROWTERMINATOR = ''\n'',
                            FIRSTROW = 2,
                            LASTROW = ', @LASTROW ,'
                            );' );
print @sqlCommand;

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执行上述脚本时出错

错误是什么？将varchar值“BULK INSERT[dbo].[TableA]从“C:\InsertTestData.txt”转换为（DATAFILETYPE='char'，FIELDTERMINATOR='，'，ROWTERMINATOR=''，FIRSTROW=''转换为数据类型int。尝试将查询中的所有int转换为varchar..ex:`2` FIRSTROW将变为varyYou知道如何将变量分配给表中的值。

BULK INSERT [dbo].[TableA] FROM 'C:\InsertTestdata.txt'
                            WITH (DATAFILETYPE = 'char',
                            FIELDTERMINATOR = ',',
                            ROWTERMINATOR = '\n',
                            FIRSTROW = 2,
                            LASTROW = 8
                            );