How to cast variables in T-SQL for bulk insert?

The following code gives an error (its part of a T-SQL stored procedure):

-- Bulk insert data from the .csv file into the staging table.
DECLARE @CSVfile nvarchar(255);
SET @CSVfile = N'T:\x.csv';
BULK INSERT [dbo].[TStagingTable]
-- FROM N'T:\x.csv' -- This line works
FROM @CSVfile -- This line will not work
WITH
(
FIELDTERMINATOR = ',',
ROWTERMINATOR = '\n',
FIRSTROW = 2    
)

Th开发者_开发技巧e error is:

Incorrect syntax near the keyword 'with'. 

If I replace:

FROM @CSVfile

with:

FROM 'T:\x.csv'

... then it works nicely.

As I know only literal string is required in the from. In that case you have to write a dynamic query to use bulk insert

declare @q nvarchar(MAX);
set @q=
    'BULK INSERT [TStagingTable]
    FROM '+char(39)+@CSVfile+char(39)+'
    WITH
    (
    FIELDTERMINATOR = '','',
    ROWTERMINATOR = ''\n'',
    FIRSTROW = 1  
    )'
exec(@q)

Have you tried with dynamic SQL?

SET @SQL = "BULK INSERT TmpStList FROM '"+@PathFileName+"' WITH (FIELDTERMINATOR = '"",""') "

and then

EXEC(@SQL)

Ref.: http://www.sqlteam.com/article/using-bulk-insert-to-load-a-text-file

you have to engage in string building & then calling EXEC() or sp_executesql BOL has an example:

DECLARE @bulk_cmd varchar(1000)
SET @bulk_cmd = 'BULK INSERT AdventureWorks2008R2.Sales.SalesOrderDetail
FROM ''<drive>:\<path>\<filename>'' 
WITH (ROWTERMINATOR = '''+CHAR(10)+''')'
EXEC(@bulk_cmd)

A string literal is required.

http://msdn.microsoft.com/en-us/library/ms188365.aspx

You could use dynamic sql to generate the string literal.

Most of the time the variable i'm looking for in a file name is the date, and this one works perfectly for bulk inserting files with date, for use such as in a daily job. Change as per your need, date format, table name, file path, file name and delimiters.

    DECLARE @DT VARCHAR (10)
    DECLARE @INSERT VARCHAR (1000)
    SET @DT = (CONVERT(VARCHAR(10),GETDATE()-1,120))
    SET @INSERT = 'BULK INSERT dbo.table FROM ''C:\FOLDER\FILE'+@DT+'.txt'''+' WITH  (FIRSTROW=2, FIELDTERMINATOR=''\t'', ROWTERMINATOR=''\n'')'
    EXEC (@INSERT);

Can you try FROM ' + @CSVfile + '